Gretchen and Charles Lambert

12001 11th Ave. NW, Seattle, WA 98177

206-365-3734 or

home page:


Number 59                                                                                                            September 2006


   Thanks again to all of you who have written in the last several months about AN and how valuable it has been and still is. A surprisingly frequent comment was similar to that by George Mackie: “It gave us ascidian fans a feeling of community, which I for one will miss.” Because we’ve done AN for 30 years, other comments were similar to Don Deibel’s: “AN has been a part of my professional life for my entire career. I will miss it.” We greatly appreciate your kind words and have decided to continue with AN for a few more years at least.

   Mike Thorndyke wrote: “One thing we'll all miss I am sure is the updates on what the both of you have been up to. That is not available on any database that I know of!” We’re not sure everyone is all that interested, but here goes the latest installment!  We spent a few weeks at the Friday Harbor Labs during June and July, then 3 exciting weeks in Panama in August teaching an intensive class on ascidian taxonomy and biology with Brazilian colleague Rosana da Rocha at the Smithsonian Tropical Research Institute at Bocas del Toro in the Caribbean. The class of 15 very dedicated, hard working participants from around the world gives us great hope for a next generation of knowledgeable ascidian taxonomists. Details about the Bocas lab are at  Details of the ascidian class are at  Adriaan Gittenberger, one of the class participants, added many excellent photos of Bocas ascidians to his website including a number of labeled photos of dissections made by his lab partner Lauren Stefaniak ( Click on the Bocas del Toro link. To our knowledge this is the only online source of labeled ascidian dissections and should be a very valuable resource for many of you.

   There are 181 new publications in this issue of the newsletter!  Keep up the good work and to assure that your new publications will appear in AN please don’t forget to send us hard copy color reprints (preferred as we do not have a color printer) or PDFs; thank you.


*Ascidian News is not part of the scientific literature and should not be cited as such.




1. Second announcement of 2007 Intl. Tunicata Conference From Christian Sardet, Station Zoologique, Observatoire, CNRS, Univ PM Curie, Villefranche sur Mer 06230, France   The meeting will be Saturday June 23 (arrivals) to Wednesday June 27 in Residence Delcloy situated in St. Jean Cap Ferrat about a mile from the Marine Station.  To see the conference site:, click on France then Mediterranee then St. Jean Cap Ferrat and click on the 360 panoramics to see the facilities.  We will establish a specific web site, and draft a preliminary program in Sept. /October. We hope you will participate and enjoy Good Science and the French Riviera.


The Villefranche team Christian Sardet, Janet Chenevert, Clare Hudson, Alex McDougall,

Hitoyoshi Yasuo, Remi Dumollard:  Things are going well and ascidians are firmly established with 3 groups (Sardet, McDougall, Yasuo) and a dozen researchers, Post Docs, technicians and students working on Ciona and Phallusia. The appendicularian work is reduced in Villefranche but is now strong in Bergen.

   We are looking for a new Director of Developmental/Cell Biology Research Unit at Villefranche-sur-mer. For further details contact our search committee



I have put an extensive collection of films of ascidian maturation, fertilization, development on the internet at

I also have 2 other fun sites The Bioclips site:

with some multimedia stories featuring ascidian eggs and embryos see "Polarity inside the egg cortex" and "Sparks of life".  The Portal with access to a large collection of films about cells issued from the new DVD "Exploring the living Cell" 3 hours of documents about the discovery, diversity, research and debates about cells: see:


2. While you have your 2007 calendar handy, please add Second Intl. Invasive Sea Squirt Conference Oct. 1-5, 2007, Prince Edward Island, Canada.   The Biology, Biogeography, and Ecology of Invasive Ascidians.

   Schedule from Mary Carman, organizer, Woods Hole Oceanog. Inst. (  arrival Monday Oct. 1 at Rodd-Brudenell River Hotel (30 min. from Charlottetown in the Brudenell River Provincial Park); Oct. 2, morning field trip/charter boat outing to view aquacultured mussel lines and walk to nearby floating docks, followed by afternoon taxonomic workshop given by Gretchen and Charles Lambert at Atlantic Veterinary College (ascidians collected during the field trip or brought from home will be welcome). Oct. 3-4 will include invited plenary talks, contributed research presentations, posters, and discussions at the hotel (banquet evening Oct. 3), with departure Oct. 5.  A special block of rooms has been reserved for us at the hotel; view their website at

   Registration and call for abstracts will open October 1, 2006.  Woods Hole Oceanographic Institution’s Ocean Life Institute (OLI) is the primary sponsor for this event.  View the conference website at for registration, details on the conference, and guidelines for abstract submission.

   Invasive ascidians are impacting ecosystems, creating a nuisance for the aquaculture industry, and are a major component of fouling communities. The aim of this conference is to bring together marine biologists, shellfishery scientists, representatives of the shellfish industry, members of local, state, and federal agencies concerned with coastal resources, and representatives from sponsoring organizations concerned with invasive ascidians, to explore the biology, ecology, impacts, management options for control, and other relevant topics.  Extended abstracts and full papers will be published.


3. From Bill Smith, UC Santa Barbara: NIH Funds Ascidian Stock Center at the University of California, Santa Barbara.

   An application for an NIH program entitled Tools for Genetic and Genomic Studies in Emerging Model Organisms, submitted by Bill Smith and Mike Levine, has been awarded. This four-year, $1 million award will provide funds for the construction of new ascidian culturing facilities at Univ. Calif.  Santa Barbara, and for staff support. The goal of the facility is the creation and distribution of transgenic Ciona lines, as well as the distribution of wild-type Ciona. This facility will be available for all researchers, and specific stable transgenic lines can be made on request. If you wish to learn more about the stock center please contact Bill Smith:


4. Van Name W.G. 1945. The North and South American ascidians. Bull.of the Am. Mus. of Nat. Hist. vol.84:1-476 is available online at  It is a very large pdf—209 mb. However, it is downloadable if you have access to high speed broadband. It can then be printed out (be sure to print double sided because of the large number of pages). Once downloaded, the advantage of having a digital copy is that it is searchable! You can easily find all the species listed for Panama or Chile, e.g., or all the pages where a particular species is mentioned or described. Although the availability of this publication online was mentioned in a previous AN, we think it is worth repeating. This very valuable monograph has been out of print for many years; we owe the AMNH a very big thanks for making it available again.



From Patrick Lamaire, Marseille, France:

The chordate Gateway vector set is now available to the ascidian community. Gateway technology allows to bypass the main problems encountered in traditional restriction enzyme-mediated cloning strategies. AgnХs Roure in the Lemaire lab in Marseille (France) generated a collection of Gateway vectors dedicated to overexpress native or fusion proteins in ascidians as well as to study the activity of cis-regulatory elements. 2 kinds of vectors were developed. The pSPE3 series is designed to synthetise mRNA in vitro, which can be micro-injected into embryos. The pSP1.72 series are transgenesis vectors designed to be electroporated into embryos. In both series, an ORF of interest can be introduced into an RfA Gateway cassette flanked by attR1 and attR2 recombination sites. Various vectors harbour N or C-terminal fusion tags (fluorescent protein or epitope) allowing to track the subcellular localisation of protein products. In addition, AgnХs developped a second, attR3-attR5 flanked Gateway cassette used to receive a cis-regulatory region (in attR3-attR5). This second cassette is placed upstream the ORF-accepting attR1-attR2 cassette in the pSP1.72 series. These vectors were all tested in vivo and shown to be functional in ascidian embryos. The whole collection is freely available upon request ( All details about the Gateway technology, vectors, sequences and procedures can be found in « V2.0 Chordate Gateway Vectors Manual » which is downloadable from our lab web site:



1. Society for Developmental Biology, Ann Arbor, Michigan June 17-21, 2006.

Two hearts beat as one: Experimental compartmentalization of the Ciona heart.  B. Davidson, W. Shi, J. Beh, L. Christiaen, M. Levine. Dev. Biol. 295: 334  #29.

   The evolution of the complex, multi-chambered vertebrate heart may have involved either sub-division of the ancestral heart field or progressive addition of supplementary cardiac lineages.  The single-chambered condition of the ancestral chordate heart has apparently been maintained within the tunicates, including Ciona intestinalis. Here, specific manipulations of progenitor cell recruitment cause compartmentalization of the Ciona heart.  We present evidence that FGF signaling induces cardiac mesoderm within a subset of competent cells. Targeted inhibition of FGF signaling blocks heart formation, and a similar loss is obtained with a constitutive repressor form of the RTK transcriptional effector, Ets1/2 (Ets-WRPW). Conversely, targeted expression of a constitutively active form of Ets1/2, Ets-VP16, throughout the heart field doubles the number of heart progenitor cells.  These excess heart cells produce an unexpected phenotype: the transformation of a one-chambered heart into a functional multi-compartment organ.  These results suggest that progenitor cell recruitment was an important step during the emergence of the vertebrate multi-chambered heart.  We propose that variability in the distribution of progenitor cells represents a general mechanism for potentiating evolution of novel internal structures. 


2.  77th annual meeting of the Zool. Soc. of Japan, Shimane Univ., Matsue, Japan, 21-24 September 2006.

a. Estrogen alters the gene expression profile in the ascidian, Ciona intestinalis. R. Koyanagi1,2, M. Yamashita3, N. Satoh4,5 and K. Azumi1,2,4.  (1, 2, 3) Hokkaido Univ., Sapporo, Japan; (4) Core Research for Evol. Sci. and Technol., Japan Science and Technology Agency, Kawaguchi, Saitama. 5) Kyoto Univ., Kyoto.

    The gene expression profile of the ascidian Ciona intestinalis in the presence of an estrogen, 17b-estradiol (E2) was analyzed. Mature adult animals were exposed to nanomolar concentrations of E2 under several different conditions. The gene expression profile of the experimental individuals has been explored using a series of DNA microarray analysis. Although no homologous gene for mammalian intracellular estrogen receptors was found in the C. intestinalis genome, the results of statistical study on the expression profiles revealed E2-dependent alteration of the profiles as well as the genes up- or down-regulated depending on the exposure time. On the other hand, the different (100-fold) concentration of E2 gave no significant effect on the profiles, suggesting that the concentration is not the primal parameter to drive the change in the gene expression profiles at the conditions tested in this study. These results show the presence of a signaling pathway to respond E2 stimulation which is independent of known vertebrate receptor and suggest E2 or estrogenic compounds as a potential endocrine disruptor for C. intestinalis. Further analysis on the expression profile will give a good scaffold to understand the molecular mechanism behind this phenomenon.


b. Roles of spermosin L-chain in fertilization of the ascidian Halocynthia roretzi. M. Akasaka, Y. Harada, and H. Sawada. Sugashima Mar. Biol. Lab., Graduate Sch. of Sci., Nagoya Univ., Sugashima, Toba 517-0004, Japan.

   We previously reported that two sperm trypsin-like proteases, acrosin and spermosin, are involved in fertilization of the ascidian Halocynthia roretzi, and that C-terminal CUB domain of ascidian proacrosin and L-chain of spermosin are capable of binding to the vitelline coat components.  But, the roles in fertilization of these regions of sperm trypsin-like proteases have not been studied well. In this context, we made the antibodies against HrProacrosin CUB-domain, HrSpermosin L2 region, and HrSpermosin L1 (BL2) region, and their effects on fertilization were examined. Although anti-CUB-domain antibody showed weak or no inhibition toward fertilization, anti-L2 antibody potently inhibited the fertilization. In contrast, anti-L1 (BL2) antibody increased the fertilization ratio in a concentration-dependent manner. These results suggest that spermosin plays a key role in ascidian fertilization and that Pro-rich L1 (BL2) region of spermosin type I may be involved in the block to fertilization. Further studies are necessary to elucidate the mechanism of stimulation in fertilization ratio by anti-spermosin L1 (BL2) antibody.


c. Vitelline-coat protein CiVC100, a candidate allorecognition protein during fertilization of the ascidian Ciona intestinalis. Y. Harada, Y. Takagaki, T. Saito, and H. Sawada.

   Ascidians are hermaphroditic, releasing both sperm and eggs almost simultaneously, but many species, such as Halocynthia roretzi and Ciona intestinalis, exhibit self-sterility.  It is reported that the barrier against self-sperm resides on the vitelline coat and that the barrier is impaired or removed by short treatment of eggs with weak acid.  We previously reported that a highly polymorphic 70-kDa vitelline-coat protein HrVC70, consisting of 12 epidermal-growth-factor (EGF)-like repeats, is a promising candidate for the allorecognition molecule during fertilization of the ascidian H. roretzi and that this protein is easily detached from the vitelline coat by short treatment with weak acid. Here, we show that a 100-kDa vitelline-coat-component CiVC100 is detached by acid treatment from the isolated vitelline coat of another ascidian, C. intestinalis. Based on the protein sequences of the protease-digested fragments of CiVC100, we attempted to identify this protein from C. intestinalis genome database. Interestingly, CiVC100 showed no homology to HrVC70, but turned out to be an apolipoprotein ortholog.


d. Functional analysis of HrUrabin, a sperm GPI-anchored protein capable of binding to a candidate allorecognition protein on the vitelline coat, HrVC70, in Halocynthia roretzi.

Y. Nakagawa, Y. Harada, and H. Sawada.

   Ascidians are hermaphrodites, but several ascidians, including Halocynthia roretzi, show strict self-sterility because of unknown molecular mechanisms. We previously reported that a highly polymorphic vitelline-coat sperm-receptor HrVC70 is a candidate allorecognition protein and that a sperm GPI-anchored 35-kDa glycoprotein HrUrabin in lipid raft fraction is capable of binding to HrVC70 in in vitroassay conditions. Here, we investigated the role of HrUrabin in fertilization by using a specific antibody against HrUrabin. We found that anti-HrUrabin antibody potently inhibited the fertilization in a concentration-dependent manner. Concerning the binding ability of sperm to HrVC70, the number of nonself-sperm bound to an HrVC70-agarose bead was significantly higher than that of self-sperm, as reported previously. Under these conditions, anti-HrUrabin antibody almost completely blocked the binding of both self- and nonself-sperm to HrVC70-agarose beads. These results indicate that HrUrabin plays a pivotal role in fertilization, in particular in the sperm binding process to HrVC70, and that there may be a sperm-derived novel allorecognition molecule in addition to HrUrabin.


3. Marine Genomics Congress, Sorrento, Italy Oct. 28-Nov. 1, 2006

HAP/APEX/Ref-1, apurinic/apyrimidic endonuclease mRNA is expressed in the oocytes of ascidian Ciona intestinalis. E. Tosti1, S. Bilotto2, S. El-Mouatassim3, Y. Menezo3, G. L. Russo1,4     1Lab Biologia Cellulare, Stazione Zoologica “Anton Dohrn”, Napoli; 2Dipartimento delle Scienze Biologiche, Univ. degli Studi di Napoli Federico II; 3Laboratoire Marcel Mérieux, Avenue Tony Garnier LYON, France; 4Istituto di Scienze dell’Alimentazione, Consiglio Nazionale delle Ricerche, Avellino.

   DNA repair is probably one of the most important processes to be performed in the oocytes and zygote, at the time of fertilization and immediately after, in order to allow complete embryonic development. APEX/Ref1, Apurinic/apyrimidinic endonuclease-Red-Ox factor1 is capable of initiating the repair of apurinic/apyrimidic (AP) sites, the most common decay, in damaged DNA. In vertebrate models, the enzyme is also supposed to play an important role in response to oxidative stress. The DNA-binding activity of APEX is modulated by a post translational mechanism involving reduction oxidation and so at least partly mediated by ROS. Preliminary data indicate that APEX mRNA is expressed in human spermatozoa and oocytes and in pre-implantation embryos. In order to investigate if the level of expression of APEX was evolutionarily conserved, we extended our study to oocytes ad spermatozoa of ascidian Ciona intestinalis, an organism intensively studied in developmental biology and, more recently, proposed as a model to study meiotic regulation. From an evolutionary point of view, tunicates (appendicularians, salps and sea squirts) have very recently been re-evaluated as the closest relatives of vertebrates, more than cephalochordates, like amphioxus. This important discovery has been made possible since the advent of genomics that actually provide the opportunity for phylogenetics to resolve a number of outstanding evolutionary questions. In this respect, the draft copy of the C. intestinalis genome became publicly available providing new insights into origin and evolution of chordates. Based on this evidence, we used C. intestinalis gametes as comparative model to study the conservativity of APEX function. Our data indicate that APEX transcripts were detected in oocytes and embryos, but not in spermatozoa, of C. intestinalis. Of phylogenetic significance is also the observation that ascidian APEX lacks redox transcriptional activity.


4. 5th Int'l Conf. on Vanadium Chemistry & Biochemistry, Am. Chem. Soc. meeting, San Francisco, Sept. 10-14, 2006

a. Towards the biological reduction mechanism of vanadyl ion in the blood cells of vanadium-sequestering tunicates. P. Frank, E.J. Carlson, R.M.K. Carlson, B. Hedman and K.O. Hodgson. Dept. of Chem., Stanford Univ., Stanford, CA.

   Nearly one hundred years after Henze reported high concentrations of vanadium and acid in some ascidians, the mechanism for the reduction of ambient V5+ to cellular V3+ remains unknown. We will report the results of x-ray absorption spectroscopic (XAS) measurements that queried the fate of vanadyl ion following uptake by living blood cells from the tunicate Ascidia ceratodes. These new results, in addition to previous results from XAS experiments and insights from the known inorganic chemistry of vanadium, will form the basis of a proposed mechanism for the biological reduction of vanadyl ion. The new field of vanadium redox-enzymology, long suspected but virtually undetected until now, has thus achieved infancy and awaits growth.


b. Genes and proteins involved in vanadium accumulation by ascidians.  H. Michibata, M. Yoshinaga, M. Yoshihara, N. Kawakami, and T. Ueki.  (

   Several species of ascidians (tunicates) accumulate high levels of vanadium in blood cells known as vanadocytes. The intracellular vanadium concentration can be as high as 350 mM, which is 107 times the concentration in seawater. Vanadium accumulated in the ascidians is reduced to the +3 oxidation state via the +4 oxidation state. From a vanadium-rich ascidian, Ascidia sydneiensis samea, genes and proteins, such as Vanabin family, enzymes in the pentose phosphate pathway, metal-ATPase, glutathione S-transferase and SO4-2 transporter, likely to be involved in vanadium accumulation, have been isolated. Molecular physiological roles of these proteins will be discussed.


c. Metal ion selectivity and affinity of wild type and mutant Vanabins. T. Ueki and H. Michibata. (  Dept. Biol. Sci. and Mar. Biol. Lab., Grad. Sch. Sci., Hiroshima Univ.

   Ascidians are well known to accumulate high levels of vanadium ion in the vacuole of one or more type(s) of blood cells. We previously identified five low molecular weight vanadium-binding proteins, designated Vanabin1, 2, 3 ,4 and P, from a vanadium-rich ascidian Ascidia sydneiensis samea. EPR and NMR analyses suggested that lysines and arginines in Vanabin1 and Vanabin2 mainly contribute as coordination sites for vanadium(IV) ions. We performed in vitro mutagenesis of Vanabin2 to modify lysines, arginines and some amino acid residues in possible binding sites, and assessed the metal binding ability of mutants by immobilized metal ion affinity chromatography. Mutation of some of lysines and arginines affected the vanadium binding ability of Vanabin2.


d. Characterization of the AsGSTs, vanadium-binding glutathione transferases isolated from the vanadium-rich ascidian Ascidia sydneiensis samea.  M. Yoshinaga, T. Ueki and H. Michibata

   Some ascidians accumulate high levels of vanadium. We have isolated novel proteins with a homology to glutathione transferases (GSTs), designated AsGST-I and AsGST-II from the digestive system of the vanadium-accumulating ascidian Ascidia sydneiensis samea. Because AsGSTs were highly expressed in the digestive system and showed vanadium-binding activity which has never been reported for GSTs isolated from other organisms, we postulate that AsGSTs play important roles in vanadium accumulation in the ascidian digestive system which is thought to be involved in vanadium-uptake. In this study, through analysis of the recombinant AsGST-I, we examined the metal-selectivity and the GST-activity in the presence of vanadium. As a result, the vanadium-binding activity was barely inhibited in the presence of magnesium(II) or molybdate(VI) ions, which indicated the high vanadium-selectivity of AsGSTs, and the GST-activity was partly inhibited in the presence of vanadium, which suggested that vanadium may be involved in control of the GST-activity.


5. 48th Symp. of the Soc. for Histochemistry: Histochemistry of Cell Damage and Death. Stresa, Lake Maggiore, Italy, 7-10 September, 2006.

a. Recognition and clearance of apoptotic cells in colonial ascidians. L. Ballarin, Dipartimento di Biologia, Università di Padova, Italy.

   The colonial ascidian Botryllus schlosseri forms new zooids by blastogenesis, through the formation of palleal buds which progressively grow and mature until an adult is formed. At a temperature of 19°C, adult zooids remain active for about one week; then they contract, close their siphons and are gradually resorbed, being replaced by buds which reach functional maturity, open their siphons and begin their filtering activity as adult zooids. This recurrent generation change, known as regression or take-over, is characterised by the occurrence of diffuse programmed cell death by apoptosis. During the take-over, circulating phagocytes infiltrate in zooid tissues and engulf apoptotic cells; in addition, the frequency of haemocytes showing nuclear condensation and annexin-V labelling significantly increases. Moreover, the number of circulating phagocytes showing a globular morphology and containing ingested cells or cell debris significantly rises whereas the frequency of hyaline amoebocytes, which represent mobile, active phagocytes decreases. Phagocytes, both professional and occasional, actively recognize senescent cells and ingest them. As regards the eat-me signals, PS seems to be involved in the recognition of effete cells, as the addition of phospho-L-serine, a soluble analogue of PS, inhibits in vitro phagocytosis of apoptotic cells. CD36, a part of the receptorial complex binding thrombospondin which act as a bridging molecule between phagocyte surface and apoptotic cells, is expressed on Botryllus phagocytes: the frequency of cells recognised by anti-CD36 antibodies significantly increases during the take-over and the expression pattern changes from a patchy distribution to a uniform staining of the phagocyte surface during the take-over. Anti-CD36 antibodies significantly decreases the phagocytosis of effete cells suggesting that similarly to that described in vertebrates the thrombospondin receptor play a role in apoptotic cell removal by phagocytes.


b. Cyclic apoptosis in the digestive tract of a protochordate. F. Cima, Dipartimento di Biologia, University of Padova, Italy.

   Tissue degeneration which occurs during development of organisms is often of morphogenetic importance as well as proliferation and differentiation. Cyclic apoptosis of organs was progressively lost in Chordates. Botryllus schlosseri is a colonial ascidian continuously forming new zooids by blastogenesis, through the recurrent formation of palleal buds, which grow and mature until an adult is formed. Three blastogenic generations are

commonly co-present: adult, filtering zooids, their buds and budlets on buds. At a temperature of 19°C, adult zooids remain active for about one week (mid-cycle stages); then they contract, close their siphons and are gradually resorbed, being replaced by a new generation of adult zooids, represented by buds which reach functional maturity, open their siphons and begin their filtering activity (regression or take-over stage). This stage is characterized by the occurrence of diffuse programmed cell death by apoptosis in zooid tissues, as evidenced by TUNEL reaction for chromatin fragmentation and annexin V labelling for detection of exposed phosphatidylserine, whereas infiltration of circulating phagocytes, which appear engulfed with apoptotic cells, is observed. With these characteristics, colonial tunicates are suitable subjects for studies on cyclical involution and resorption of tissues. In residual zooids remaining for a long time in the centre of each colony, melanin and lipofuscins accumulate as detected with Masson-Fontana, Ziehl-Nielsen and H2O2 bleaching methods.  Immunocytochemical assays to detect pro- and antiapoptotic factors reveal an opposite expression which progressively extends in tissues of adult zooids with an organ gradient starting from the branchial basket. Results support the idea that fundamental mechanisms for the induction of apoptosis are well conserved throughout Chordate evolution.


6. 12th Intl. Conf. on Biol. Inorganic Chem., July 31-Augst 5 2005, Ann Arbor, Michigan USA.

a. Vanadium in Biology: Accumulation Mechamism in Ascidians.  H. Michibata, T. Ueki, et al. Dept. Biol. Sci. and Mar. Biol. Lab., Grad. Sch. Sci., Hiroshima Univ.

   Ascidians are well known to contain high levels of vanadium.  In remarkable cases, the concentration of cellular vanadium reaches 350 mM, corresponding to about 107 times the concentration of seawater.  Vanadium accumulated in ascidians is reduced to the +3 oxidation state via the +4 oxidation state and stored in vacuoles of vanadocytes.  From the vanadocytes of a vanadium-rich ascidian, Ascidia sydneiensis samea, we isolated some vanadium binding proteins, designated as Vanabin.  Recently, we identified five types of Vanabin: Vanabin1, Vanabin2, Vanabin3, Vanabin4 and VanabinP that are likely to be involved in vanadium accumulation processes as so-called metallochaperones.  Among them, recombinant proteins of Vanabin1 and Vanabin2 bound to 10 and 20 vanadium(IV) ions with dissociation constants of 2.1 в 10-5 M and 2.3 в 10-5 M, respectively.  Multi-dimensional NMR experiments have revealed the first 3D structure of Vanabin2 in an aqueous solution which shows novel bow-shaped conformation, with four ?-helices connected by nine disulfide bonds.  There are no structural homologues reported so far. The 15N HSQC perturbation experiments of Vanabin2 indicated that vanadyl cations, which are exclusively localized on the same face of the molecule, are coordinated by amine nitrogens derived from amino acid residues such as lysines, arginines, and histidines, as suggested by the EPR results.  Recently, glutathione S-transferase (GST), known to protect organisms against oxidative stress induced by heavy metals, was extracted from digestive organs of a vanadium-rich ascidian.  Recombinant protein of ascidian GST was found to bind with vanadium(IV).  A significance of the vanadium-binding property is under investigation.


b. Study on vanadium-binding proteins of an ascidian Ascidia sydneiensis samea. T. Ueki, M. Yoshihara, N. Yamaguchi, K. Fukui, and H. Michibata.

   Ascidians are well known to accumulate high levels of vanadium ion in the vacuole of one or more type(s) of blood cells.  We previously identified five low molecular weight vanadium-binding proteins, designated Vanabins, from the vanadocytes and the ceolomic fluid of a vanadium-rich ascidian Ascidia sydneiensis samea. We examined the activities of Vanabins to bind vanadium(IV) ions by Hummel-Dreyer's method.  Recombinant proteins of the two Vanabins, Vanabin1 and Vanabin2, bound to 10 and 20 vanadium(IV) ions with dissociation constants of 2.1 X 10-5 M and 2.3 X 10-5 M, respectively.  EPR analysis supported these results and indicated that amine nitrogens coordinate with vanadium (IV) ions. VanabinP, which is one of most abundant proteins in ceolomic fluid, also bound to vanadium (IV) ions at a similar value (maximum 13 vanadium ions at Kd=2.8x10-5M).  Although Vanabin1, Vanabin2 and VanabinP are transcribed in blood cells, their distribution patterns are different; Vanabin1 and Vanabin2 are in cytoplasm of signet ring cells (vanadocytes) while VanabinP is in coelomic fluid.  These results suggested that Vanabin1 and VanabinP act as cytoplasmic vanadium carrier proteins, and VanabinP as a vanadium carrier protein in coelomic fluid, since vanadium(IV) is easily precipitated at physiological pH range. The distribution and function of Vanabins are discussed.


c. Glutathione S-transferase having vanadium-binding activity isolated from a vanadium-accumulating ascidian, Ascidia sydneiensis samea.  M. Yoshinaga, K. Kamino, N. Yamaguchi, T. Ueki, and H. Michibata. (M. Yoshinaga, a PhD student of Prof. Michibata, won the best poster award, Faustus Poster Award.)

   Several species of ascidians accumulate vanadium in their vanadocytes, vanadium containing blood cells, at high concentration and with high selectivity. Through the accumulation process, almost vanadium ions in the +5 oxidation state are mostly reduced to the +3 oxidation state via the +4 oxidation state and stored in the vacuole of vanadocytes. For hunting new factors involved in this unique phenomenon, we have tried to isolate novel vanadium-binding proteins from tissue extracts of a vanadium-rich ascidian, Ascidia sydneiensis samea, by using a vanadium-chelating column, and consequently several vanadium-associated proteins have been isolated. We aimed at one of the proteins expressed highly in the digestive organ, and its N-terminal amino acid sequence was determined. To screen the cDNA corresponding to the protein, a degenerate primer corresponding to the amino acid sequence and cDNA library of vanadocytes were used for polymerase chain reaction. As a result, a single DNA fragment was amplified. Analysis of the DNA sequence revealed that the estimated amino acid sequence of the protein shows a striking homology with glutathione S-transferase (GST), named as AsGST.  One of the most important functions of GSTs in organisms is protection against oxidative stress induced by heavy metals. Additionally glutathione (GSH), the cofactor of GSTs, is known to modulate mobilization and toxicity of metals such as cadmium and copper, and behaves as a reducing agent for metals including vanadium. Therefore, we supposed that AsGST and GSH might play important roles during the process of vanadium accumulation in ascidians.  Availability of one-step isolation of the recombinant protein of AsGST cloned and expressed in E. coli. We confirmed by a vanadium-chelating column confirmed that the recombinant protein of AsGST certainly has vanadium-binding activity using a vanadium-chelating column., In addition AsGST wais disclosed to be dimeric as same as other GSTs and have has GST activity with 1-chloro-2,4-dinitrobenzene (CDNB), one of general substances of GSTs. The correlation between vanadium-binding property and GST activity is under investigation.


7. 1st European Chemistry Congress, 27-31 Aug. 2006 Budapest, Hungary.

Selective metal binding by Vanabin2 from the vanadium-rich ascidian, Ascidia sydneiensis samea.  N. Kawakami, T. Ueki, K. Matsuo, K. Gekko & H. Michibata. Grad. Sch. Sci., Hiroshima Univ.

   Vanadium-binding proteins, or Vanabins, have recently been isolated from the vanadium-rich ascidian, Ascidia sydneiensis samea. Recent reports indicate that Vanabin2 binds 20 V(IV) ions at pH 7.5, and that it has a novel bow-shaped conformation. However, the role of Vanabin2 in vanadium accumulation by the ascidian has not yet been determined. In this study, the effects of acidic pH on selective metal binding to Vanabin2 and on the secondary structure of Vanabin2 were examined. Vanabin2 selectively bound to V(IV), Fe(III), and Cu (II) ions under acidic conditions. In contrast, Co(II), Ni(II), and Zn (II) ions were bound at pH 6.5 but not at pH 4.5. Changes in pH had no detectable effect on the secondary structure of Vanabin2 under acidic conditions, as measured by circular dichroism spectroscopy, and little variation in the dissociation constant for V(IV) ions was observed in the pH range 4.5-7.5, suggesting that the binding state of the ligands is not affected by acidification. Taken together, these results suggest that the reason for metal ion dissociation upon acidification is attributable not to a change in secondary structure but, rather, that it is caused by protonation of the amino acid ligands that complex with V(IV) ions.




1. Confocal scanning microscopy of fluorescent lectin- and antibody-labeled Ascidia ceratodes eggs. Mia Meeyaong-Won Botkin. M.S. thesis advisor: Robert A. Koch, Laboratory for Sperm Cell Biology and Gamete Ultrastructure, Dept. of Biol. Sci., California State Univ., Fullerton, USA ( )

   The distributions of carbohydrates and proteins on the membrane or in the extracellular matrix determine the characteristics of binding to and penetration of the egg complex by sperm.  The Ascidia ceratodes egg complex consists of several layers; moving from the outside to the central oocyte, the non-cellular vitelline coat consists of the outer fibrous, central dense, inner fibrous, and perivitelline fibrous layers (OFL, CDL, IFL, and PVFL, respectively), and cellular VC (CVC) consists of the follicle (FC) and test cells (TC).  This study sought to determine by confocal microscopy what glycans and extracellular matrix proteins were located in these layers of the VC.  The lectins succinyl-Concanavalia ensiformis agglutinin (suc-ConA), soybean agglutinin (SBA), Limulus polyphemus agglutinin (LPA), and Peanut agglutinin labeled CVC.  Ulex europaeus agglutinin-1 (UEA-1) and Maclura pomifera agglutinin (MPA) labeled FCs.  Succinyl-wheat germ agglutinin (suc-WGA) labeled the FCs and OFL.  Thus, mannose, glucose, N-acetyl-D-galactosamine (GalNAc), galactose, and sialic acid were found in the CVC; high amounts of fucose and low amounts of GalNAc and galactose were present in the FCs; and, N-acetyl-D-glucosamine was on the FCs and OFL.  Antibody labeling showed that fibronectin and chondroitin sulfate were present in and on the FCs and TCs; fibronectin was in the IFL; keratan sulfate was on the surface of the VC and CDL; and hyaluronan was distributed on the surfaces of the CVC.


2. Characterizing membrane potential changes during ascidian sperm activation. Reginald McNulty. M.S. thesis advisor: Robert A. Koch, Laboratory for Sperm Cell Biology and Gamete Ultrastructure, Dept. of Biol. Sci., California State Univ.. Fullerton

    In Ascidia ceratodes sperm activation, there is evidence that activation of a Na+/H+ exchanger causes an increase in pHi and a subsequent increase in [Ca2+]i from both intracellular and extracellular sources.  However, the link between pHi, Em, and [Ca2+]i has not been investigated.  The goal of this research was to characterize the membrane potential changes that take place during ascidian sperm activation.  A voltage-sensitive dye was used to measure changes in sperm membrane potential in batches of sperm.  When sperm were activated with pH 9.4 ASW and the G-protein activator mas7, a hyperpolarization and subsequent depolarization was observed.  Ion-substitution experiments supported that the hyperpolarization is K+-dependent and not Cl- -dependent and established an internal K+ concentration of 336mM.  Valinomycin experiments established a resting membrane potential of -68.9 mV.  The osmoregulator blocker furosemide, voltage-gated channel blocker 4-aminopyridine, and the Ca2+ low-voltage channels blockers pimozide and penfluridol inhibited hyperpolarization.  However, high, low, intermediate KCa blockers, and the voltage-gated K+ channel blocker TEA, had no effect on the hyperpolarization.  Identifying the cause of hyperpolarization is important because disabling it inhibits sperm activation.




Aiello, A., Fattorusso, E., Luciano, P., Mangoni, A. and Menna, M. 2005. Isolation and structure determination of aplidinones A-C from the Mediterranean ascidian Aplidium conicum: A successful regiochemistry assignment by quantum mechanical C-13 NMR chemical shift calculations. Eur. J. Org. Chem. 23: 5024-5030.

Anno, C., Satou, A. and Fujiwara, S. 2006. Transcriptional regulation of ZicL in the Ciona intestinalis embryo. Dev. Genes & Evol. 216 (10): 597-605.

Ballarin, L. and Burighel, P. 2006. RGD-containing molecules induce macropinocytosis in ascidian hyaline amoebocytes. J. Invert. Pathol. 91: 124-130.

Bandaranayake, W. M. 2006. The nature and role of pigments of marine invertebrates. Nat. Prod. Rep. 23: 223-255.

Barnes, D. K. A. 2005. Changing chain: past, present and future of the Scotia Arc's and Antarctica's shallow benthic communities. Scientia Marina 69 suppl. 2: 65-89.

Barnes, P. B., Davis, A. R. and Roberts, D. E. 2006. Sampling patchily distributed taxa: a case study using cost–benefit analyses for sponges and ascidians in coastal lakes of New South Wales, Australia. Mar. Ecol. Prog. Ser. 319: 55–64.

Bellas, J. 2005. Toxicity assessment of the antifouling compound zinc pyrithione using early developmental stages of the ascidian Ciona intestinalis. Biofouling 21: 289-96.

Bellas, J. 2006. Comparative toxicity of alternative antifouling biocides on embryos and larvae of marine invertebrates. Sci. Total Environ. 367: 573-585.

Berry, Y., Bremner, J. B., Davis, A. and Samosorn, S. 2006. Isolation and NMR spectroscopic clarification of the alkaloid 1,3,7-trimethylguanine from the ascidian Eudistoma maculosum. Nat. Prod. Res. 20: 479-483.

Bishop, J. D. D. and Pemberton, A. J. 2006. The third way: spermcast mating in sessile marine invertebrates. Integr. Comp. Biol. 46: 398-406.

Blunt, J. W., Copp, B. R., Munro, M. H., Northcote, P. T. and Prinsep, M. R. 2006. Marine natural products. Nat. Prod. Rep. 23: 26-78.

Bothwell, M. 2006. Evolution of the neurotrophin signaling system in invertebrates. Brain, Behav. & Evol. 68: 124-132.

Bourque, D., MacNair, N., LeBlanc, A., Landry, T. and Miron, G. 2005. Preliminary study of the diel variation of ascidian larvae concentrations in Prince Edward Island. Canad. Tech. Report of Fisheries and Aquatic Sci. 2571: 1-16.

Breton, G. 2005. Le Port du Havre (Manche Orientale, France) et ses peuplements: un exemple de domaine paralique en climat tempéré. Bull. Soc. Zool. France 130: 381 - 423.

Breton, G., Vincent, T., Painblanc, A. and Duchemin, A. 2005. L'endofaune des bassins du port du Havre (Manche orientale). Bull. Soc. géol. Normandie Amis Mus. Havre 92: 5-18.

Brown, E. R., Nishino, A., Bone, Q., Meinertzhagen, I. A. and Okamura, Y. 2005. GABAergic synaptic transmission modulates swimming in the ascidian larva. Eur. J. Neurosci. 22: 2541-2548.

Cañestro, C., Postlethwait, J. H., Gonzalez-Duarte, R. and Albalat, R. 2006. Is retinoic acid genetic machinery a chordate innovation? Evol. & Dev. 8: 394-406.

Cima, F., Burighel, P. and Ballarin, L. 2005. Ascidians as models for studying effects of antifouling compounds on biodiversity in the Lagoon of Venice. In: Lasserre, P., Viaroli, P. and Campostrini, P. (ed.), Lagoons and Coastal Wetlands in the Global Change Context: Impacts and Management Issues. Proc. of the Intl. Conf., Venice, 26-28 April 2004. UNESCO, pp. 315-322.

Cima, F., Burighel, P. and Ballarin, L. 2006. Temporal and biotic evolution of "Botryllus biocenosis" in the presence of antifouling paints. In: Campostrini, P. (ed.), Scientific Research and safeguarding of Venice. Research Programme 2004-2006. Venice, CORILA, pp. 239-246.

Cima, F., Sabbadin, A., Zaniolo, G. and Ballarin, L. 2006. Colony specificity and chemotaxis in the compound ascidian Botyllus schlosseri. Comp. Biochem. Physiol. A epub:

Cinar, M. E., Bilecenoglu, M., Ozturk, B. and Can, A. 2006. New records of alien species on the Levantine coast of Turkey. Aquatic Invasions 1: 84-90.

Coisy-Quivy, M., Sanguesa-Ferrer, J., Weill, M., Johnson, D. S., Donnay, J. M., Hipskind, R., Fort, P. and Philips, A. 2006. Identification of Rho GTPases implicated in terminal differentiation of muscle cells in ascidia. Biol. Cell epub:

Collin, R. 2005. Ecological monitoring and biodiversity surveys at the Smithsonian Tropical Research Institute’s Bocas del Toro Research Station. Caribb. J. Sci. 41: 367-373.

Collin, R., Diaz, M. C., Norenburg, J., Rocha, R. M., Sanchez, J. A., Schulze, A., Schwartz, M. and Valdes, A. 2005. Photographic identification guide to some common marine invertebrates of Bocas Del Toro, Panama. Caribb. J. Sci. 41: 638-707.

Cuomo, A., Silvestre, F., De Santis, R. and Tosti, E. 2006. Ca2+ and Na+ current patterns during oocyte maturation, fertilization, and early developmental stages of Ciona intestinalis. Molec. Repro. & Develop. 73: 501–511.

D'Agati, P. and Cammarata, M. 2006. Comparative analysis of thyroxine distribution in ascidian larvae. Cell Tiss. Res. 323: 529-535.

D'Aniello, S., D'Aniello, E., Locascio, A., Memoli, A., Corrado, M., Russo, M. T., Aniello, F., Fucci, L., Brown, E. R. and Branno, M. 2006. The ascidian homolog of the vertebrate homeobox gene Rx is essential for ocellus development and function. Differentiation 74: 222-234.

Davidson, B. and Christiaen, L. 2006. Linking chordate gene networks to cellular behavior in ascidians. Cell 124: 247-250.

De Tomaso, A. W., Nyholm, S. V., Palmeri, K. J., Ishizuka, K. J., Ludington, W. B., Mitchel, K. and Weissman, I. L. 2005. Isolation and characterization of a protochordate histocompatibility locus. Nature 438: 454-459.

DeLigio, J. T. and Ellington, W. R. 2006. The capacity for the de novo biosynthesis of creatine is present in the tunicate Ciona intestinalis and is likely widespread in other protochordate and invertebrate groups. Comp. Biochem. Physiol. D: Genomics & Proteomics 1: 167-178.

Delsuc, F., Brinkmann, H., Chourrout, D. and Philippe, H. 2006. Tunicates and not cephalochordates are the closest living relatives of vertebrates. Nature 439: 965-968.

Desnitskii, A. G. 2006. Evolutionary reorganizations of ontogenesis in ascidians of the genus Molgula. In Russian; English summary. Ontogenez 37: 85-90.

Di Gregorio, A. and Hadjantonakis, A. K. 2006. The multidimensionality of cell behaviors underlying morphogenesis: a case study in ascidians. BioEssays 28: 874-879.

Diyabalanage, T., Amsler, C. D., McClintock, J. B. and Baker, B. J. 2006. Palmerolide A, a cytotoxic macrolide from the Antarctic tunicate Synoicum adareanum. J. Amer. Chem. Soc. 128: 5630-5631.

Dubischar, C. D., Pakhomov, E. A. and Bathmann, U. V. 2006. The tunicate Salpa thompsoni ecology in the Southern Ocean. II. Proximate and elemental composition. Mar. Biol. 149: 625-632.

Dufour, H. D., Chettouh, Z., Deyts, C., de Rosa, R., Goridis, C., Joly, J. S. and Brunet, J. F. 2006. Precraniate origin of cranial motoneurons. Proc. Nat. Acad. Sci. 103: 8727-8732.

Dumollard, D., Duchen, M. and Sardet, C. 2006. Calcium signals and mitochondria at fertilisation. Semin. Cell Dev. Biol. 17: 314-323.

Fedorov, S. N., Radchenko, O. S., Shubina, L. K., Balaneva, N. N., Bode, A. M., Stonik, V. A. and Dong, Z. G. 2006. Evaluation of cancer-preventive activity and structure-activity relationships of 3-demethylubiquinone Q(2), isolated from the ascidian Aplidium glabrum, and its synthetic analogs. Pharm. Res. 23: 70-81.

Feng, D. Q., Huang, Y. and Ke, C. H. 2006. Settlement and metamorphosis of Styela canopus Savigny larvae in response to some neurotransmitters and thyroxin. Acta Oceanologica Sinica 25: 90-97.

Frank, P., De Tomaso, A., Hedman, B. and Hodgson, K. O. 2006. A new structural motif for biological iron: iron K-Edge XAS reveals a [Fe4-Ì-(OR)5(OR)9-10] cluster in the ascidian Perophora annectens. Inorg. Chem. 45: 3920-3931.

Fujiwara, S. 2006. Retinoids and nonvertebrate chordate development. J. Neurobiol. 66: 645-652.

Fukunaga, Y., Kurahashi, M., Tanaka, K., Yanagi, K., Yokota, A. and Harayama, S. 2006. Pseudovibrio ascidiaceicola sp. nov., isolated from ascidians (sea squirts). Intl. J. Syst. & Evol. Microbiol. 56: 343-7.

Gandra, M., Kozlowski, E. O., Andrade, L. R., de Barros, C. M., Pascarelli, B. M., Takiya, C. M. and Pavao, M. S. 2006. Collagen colocalizes with a protein containing a decorin-specific peptide in the tissues of the ascidian Styela plicata. Comp. Biochem. Physiol. B Biochem. Mol. Biol. 144: 215-222.

Ganot, P., Bouquet, J. M. and Thompson, E. M. 2006. Comparative organization of follicle, accessory cells and spawning anlagen in dynamic semelparous clutch manipulators, the urochordate Oikopleuridae. Biol. Cell 98: 389-401.

Garcia-Cagide, A., Hernandez-Zanuy, A. and Cardenas, A. 2005. Fecundity and early larval development of the ascidian Ecteinascidia turbinata (Ascidiacea: Perophoridae) in Cuba. Boletin de Investigaciones Marinas y Costeras 34: 141-159.

Gee, H. 2006. Evolution: careful with that amphioxus. Nature 439: 923-924.

Goodbody, I. and Cole, L. 2006. The tropical western Atlantic Perophoridae (Ascidiacea) II. The genus Ecteinascidia. Bull. Mar. Sci. 79: 49–70.

Green, P., Luty, A., Nair, S., Radford, J. and Raftos, D. 2006. A second form of collagenous lectin from the tunicate, Styela plicata. Comp. Biochem. Physiol. B.: Biochem. Mol. Biol. 144: 343-350.

Guenther, J., Southgate, P. C. and de Nys, R. 2006. The effect of age and shell size on accumulation of fouling organisms on the Akoya pearl oyster Pinctada fucata (Gould). Aquaculture 253: 366-373.

Gyoja, F. 2006. Expression of a muscle determinant gene, macho-1, in the anural ascidian Molgula tectiformis. Dev. Genes & Evol. 216 (5): 285-289.

Havenhand, J. N., Matsumoto, G. I. and Seidel, E. 2006. Megalodicopia hians in the Monterey submarine canyon: Distribution, larval development, and culture. Deep Sea Res. Part 1 -Oceanog. res. papers 53: 215-222.

Henry, L. A., Kenchington, E. L. R., Kenchington, T. J., MacIsaac, K. G., Bourbonnais-Boyce, C. and Gordon, D. C. J. 2006. Impacts of otter trawling on colonial epifaunal assemblages on a cobble bottom ecosystem on Western Bank (northwest Atlantic). Mar. Ecol. Prog. Ser. 306: 63–78.

Hinchey, E. K., Schaffner, L. C., Hoar, C. C., Vogt, B. W. and Batte, L. P. 2006. Responses of estuarine benthic invertebrates to sediment burial: the importance of mobility and adaptation. Hydrobiologia 556: 85-98.

Hirabayashi, S., Kasai, F., Watanabe, M. M. and Hirose, E. 2006. Contents of ultraviolet-absorbing substances in two color morphs of the photosymbiotic ascidian Didemnum molle. Hydrobiologia 571: 419–422.

Hirose, E., Adachi, R. and Kuze, K. 2006. Sexual reproduction of the Prochloron-bearing ascidians, Trididemnum cyclops and Lissoclinum bistratum, in subtropical waters: seasonality and vertical transmission of photosymbionts. J. Mar. Biol. Ass. U.K. 86: 175-179.

Hirose, E., Aoki, M. N. and Nishikawa, J. 2005. Still alive? Fine structure of the barrels made by Phronima (Crustacea: Amphipoda). J. Mar. Biol. Ass. U.K. 85: 1435-1439.

Hirose, E. and Fukuda, T. 2006. Vertical transmission of photosymbionts in the colonial ascidian Didemnum molle: the larval tunic prevents symbionts from attaching to the anterior part of larvae. Zool. Sci. 23: 669-674.

Hirose, E., Hirabayashi, S., Hori, K., Kasai, F. and Watanabe, M. M. 2006. UV protection in the photosymbiotic ascidian Didemnum molle inhabiting different depths. Zool. Sci. 23: 57-63.

Hirose, E., Hirose, M. and Neilan, B. A. 2006. Localization of symbiotic cyanobacteria in the colonial ascidian Trididemnum miniatum (Didemnidae, Ascidiacea). Zool. Sci. 23: 435-442.

Hiruta, J., Mazet, F. and Ogasawara, M. 2006. Restricted expression of NADPH oxidase/peroxidase gene (Duox) in zone VII of the ascidian endostyle. Cell Tiss. Res.

Horn, R. 2005. Electrifying phosphatases. Science epub

Hozumi, A., Satouh, Y., Makino, Y., Toda, T., Ide, H., Ogawa, K., King, S. M. and Inaba, K. 2006. Molecular characterization of Ciona sperm outer arm dynein reveals multiple components related to outer arm docking complex protein 2. Cell Motil. Cytoskel. 63: 591-603.

Hudson, C. and Yasuo, H. 2006. A signalling relay involving Nodal and Delta ligands acts during secondary notochord induction in Ciona embryos. Development 133: 2855-2864.

Iguchi, N. and Kidokoro, H. 2006. Horizontal distribution of Thetys vagina Tilesius (Tunicata, Thaliacea) in the Japan Sea during spring 2004. J. Plankton Res. 28: 537-541.

Imai, K. S., Levine, M., Satoh, N. and Satou, Y. 2006. Regulatory blueprint for a chordate embryo. Science 312: 1183-1187.

Jang, W. S., Kim, H. K., Lee, K. Y., Kim, S. A., Han, Y. S. and Lee, I. H. 2006. Antifungal activity of synthetic peptide derived from halocidin, antimicrobial peptide from the tunicate, Halocynthia aurantium. FEBS Lett. 580: 1490-1496.

Jeffery, W. R. 2006. Ascidian neural crest-like cells: phylogenetic distribution, relationship to larval complexity, and pigment cell fate. J. Exp. Biol. B: 306B (5): 470-480.

Jeong, J. H. and Weinreb, S. M. 2006. Formal total synthesis of the cytotoxic marine ascidian alkaloid haouamine A. Org. Lett. 8: 2309-2312.

Jewett, E. B., Hines, A. H. and Ruiz, G. 2005. Epifaunal disturbance by periodic low levels of dissolved oxygen: native vs. invasive species response. Mar. Ecol. Prog. Ser. 304: 31-44.

Jiang, A. L. and Wang, C. H. 2006. Antioxidant properties of natural components from Salvia plebeia on oxidative stability of ascidian oil. Process Biochem. 41: 1111-1116.

Jin, G., Zhang, Q. M., Satou, Y., Satoh, N., Kasai, H. and Yonei, S. 2006. Cloning and characterization of an ascidian homolog of the human 8-oxoguanine DNA glycosylase (Ogg1) that is involved in the repair of 8-oxo-7,8-dihydroguanine in DNA in Ciona intestinalis. Int. J. Radiat. Biol. 82: 241-250.

Johnson, D. S., Davidson, B., Brown, C. D., Smith, W. C. and Sidow, A. 2005. Noncoding regulatory sequences of Ciona exhibit strong correspondence between evolutionary constraint and functional importance. Genome Res. 14: 2448-2456.

Kano, S., Satoh, N. and Sordino, P. 2006. Primary genetic linkage maps of the ascidian, Ciona intestinalis. Zool. Sci. 23: 31-39.

Kawai, K., Adachi, S., Saito, H. and Imabayashi, H. 2006. Renewal of genetic composition of a lancelet, Branchiostoma belcheri, in the Seto Inland Sea, Japan. Zool. Sci. 23: 375-381.

Kawakami, N., Ueki, T., Matsuo, K., Gekko, K. and Michibata, H. 2006. Selective metal binding by Vanabin2 from the vanadium-rich ascidian, Ascidia sydneiensis samea. Biochim. Biophys. Acta 1760: 1096-1101.

Kawamura, K., Kariya, Y. and Ono, Y. 2006. Molecular collaborations between serpins and trefoil factor promote endodermal cell growth and gastrointestinal differentiation in budding tunicates. Dev. Growth & Differ. 48: 309-322.

Kawamura, K., Takeoka, S., Takahashi, S. and Sunanaga, T. 2006. In vitro culture of mesenchymal lineage cells established from the colonial tunicate Botryllus primigenus. Zool. Sci. 23: 245-254.

Kelmo, F., Attrill, M. J. and Jones, M. B. 2006. Mass mortality of coral reef ascidians following the 1997/1998 El Nino event. Hydrobiologia 555: 231-240.

Khalaman, V. V. 2005.  Long-term changes in shallow-water fouling communities of the White Sea. Biologiya Morya (Vladivostok) 31: 406-413.

Klein, J. 2006. The grapes of incompatibility. Dev. Cell 10: 2-4.

Konishi, I., Hosokawa, M., Sashima, T., Kobayashi, H. and Miyashita, K. 2006. Halocynthiaxanthin and fucoxanthinol isolated from Halocynthia roretzi induce apoptosis in human leukemia, breast and colon cancer cells. Comp. Biochem. Physiol. C Toxicol Pharmacol. 142: 53-59.

Kumano, G., Yamaguchi, S. and Nishida, H. 2006. Overlapping expression of FoxA and Zic confers responsiveness to FGF signaling to specify notochord in ascidian embryos. Dev.  Biol. epub: Aug.

Kuratani, S., Wada, H., Kusakabe, R. and Agata, K. 2006. Evolutionary embryology resurrected in Japan with a new molecular basis: Nori Satoh and the history of ascidian studies originating in Kyoto during the 20th century. Intl. J. Dev. Biol. 50: 451-454.

Kusakabe, T. 2005. Regulation and evolution of genes in ascidians. Zool. Sci. 22: 1372.

Kusakabe, T. and Tsuda, M. 2006. Photoreceptive systems in ascidians. Photochem. Photobiol. epub:

Lacalli, T. C. 2006. Prospective protochordate homologs of vertebrate midbrain and MHB, with some thoughts on MHB origins. Int. J. Biol. Sci. 2: 104-109.

Laird, D. J., De Tomaso, A. W. and Weissman, I. L. 2005. Stem cells are units of natural selection in a colonial ascidian. Cell 123: 1351-1360.

Lamb, A. and Hanby, B. P. 2005. Marine Life of the Pacific Northwest - A Photographic Encyclopedia of Invertebrates, Seaweeds and Selected Fishes. Harbour Publishing, Madeira Park, BC. 398 pp.

Lamy, C., Rothbacher, U., Caillol, D. and Lemaire, P. 2006. Ci-FoxA-a is the earliest zygotic determinant of the ascidian anterior ectoderm and directly activates Ci-sFRP1/5. Development 133: 2835-2844.

Lemaire, P. 2006. Developmental biology. How many ways to make a chordate? Science 312: 1145-1146.

Lindsay, H., Todd, C. D., Fernandes, T. and Huxham, M. 2006. Recruitment in epifaunal communities: an experimental test of the effects of species composition and age. Mar. Ecol. Prog. Ser. 307: 49–57.

Litman, G. W. 2006. How Botryllus chooses to fuse. Immunity 25: 13-15.

Liu, L. P., Wu, C. G., Cben, T. Y., Zhang, X. J., Li, F. H., Luo, W. and Xiang, J. H. 2006. Effects of infection of EGH-expressing Escherichia coli on haemocytes in Ciona intestinalis. J. Exp. Mar. Biol. Ecol. 332: 121-134.

Liu, L. P., Xiang, J. H., Dong, B., Natarajan, P., Yu, K. J. and Cai, N. E. 2006. Ciona intestinalis as an emerging model organism: its regeneration under controlled conditions and methodology for egg dechorionation. J. Zhejiang Univ. Sci .B 7: 467-474.

López-Legentil, S., Bontemps-Subielos, N., Turon, X. and Banaigs, B. 2006. Temporal variation in the production of four secondary metabolites in a colonial ascidian. J. Chem. Ecol. epub:

López-Legentil, S. and Turon, X. 2006. Population genetics, phylogeography and speciation of Cystodytes (Ascidiacea) in the western Mediterranean Sea. Biol. J. Linn. Soc. 88: 203-214.

López-Legentil, S., Turon, X. and Planes, S. 2006. Genetic structure of the star sea squirt, Botryllus schlosseri, introduced in southern European harbours. Mol. Ecol. epub:

López-Legentil, S., Turon, X. and Schupp, P. 2006. Chemical and physical defenses against predators in Cystodytes (Ascidiacea). J. Exp. Mar. Biol. Ecol. 332: 27– 36.

López-Victoria, M., Zea, S. and Weil, E. 2006. Competition for space between encrusting excavating Caribbean sponges and other coral reef organisms. Mar. Ecol. Prog. Ser. 312: 113-121.

Manni, L. and Burighel, P. 2006. Common and divergent pathways in alternative developmental processes of ascidians. BioEssays 28: 902–912.

Manni, L., Mackie, G. O., Caicci, F., Zaniolo, G. and Burighel, P. 2006. Coronal organ of ascidians and the evolutionary significance of secondary sensory cells in chordates. J. Comp. Neurol. 495: 363-373.

Manning, T., Rhodes, E., Loftis, R., Phillips, D., Demaria, D., Newman, D. and Rudloe, J. 2006. ET743: Chemical analysis of the sea squirt Ecteinascidia turbinata ecosystem. Nat. Prod. Res. 20: 461-473.

Manríquez, P. H. and Castilla, J. C. 2005. Self-fertilization as an alternative mode of reproduction in the solitary tunicate Pyura chilensis. Mar. Ecol. Prog. Ser. 305: 113-125.

Marchenkov, A. and Boxshall, G. A. 2002. The Buproridae Thorell, 1859, a family of ascidicolous copepods (Copepoda: Cyclopoida). Syst. Parasitol. 53: 191-198.

Marshall, D. J. 2006. Reliably estimating the effect of toxicants on fertilization success in marine broadcast spawners. Mar. Pollution Bull. 52: 734-738.

Marti, R., Uriz, M. J. and Turon, X. 2005. Spatial and temporal variation of natural toxicity in cnidarians, bryozoans and tunicates in Mediterranean caves. Scientia Marina 69: 485-492.

Mastrototaro, F. and Brunetti, R. 2006. The non-indigenous ascidian Distaplia bermudensis in the Mediterranean: comparison with the native species Distaplia magnilarva and Distaplia lucillae sp. nov. J. Mar. Biol. Ass. U.K. 86: 181-185.

Mastrototaro, F. and Dappiano, M. 2005. New record of the non-indigenous species Microcosmus squamiger (Ascidiacea: Stolidobranchia) in the harbour of Salerno (Tyrrhenian Sea, Italy). J. Mar. Biol. Ass. U.K. epub: JMBA2 Biodiversity Records 2005.

Maury, B., Martinand-Mari, C., Chambon, J. P., Soule, J., Degols, G., Sahuquet, A., Weill, M., Berthomieu, A., Fort, P., Mangeat, P. and Baghdiguian, S. 2006. Fertilization regulates apoptosis of Ciona intestinalis extra-embryonic cells through thyroxine (T4)-dependent NF-kappaB pathway activation during early embryonic development. Dev. Biol. 289: 152-165.

McKay, M. J., Carroll, A. R. and Quinn, R. J. 2005. Perspicamides A and B, quinolinecarboxylic acid derivatives from the Australian ascidian Botrylloides perspicuum. J. Nat . Prod. 68: 1776-1778.

Menin, A. and Ballarin, L. 2006. Exogenous IL-8 induces phagocyte activation in the compound ascidian Botryllus schlosseri. Invert. Survival J. 3: 18-24.

Miller, R. L. 2005. Gamete interactions and fertilization behavior in the larvacean, Oikopleura dioica. Invert. Repro. & Dev. 47: 73-89.

Minchin, D. 2006. The transport and the spread of living aquatic species. In: Davenport, J. L. and Davenport, J. (ed.), Environmental Pollution 10: The Ecology of Transportation: managing mobility for the environment. pp. 77-97.

Minchin, D., Davis, M. H. and Davis, M. E. 2006. Spread of the Asian tunicate Styela clava Herdman, 1882 to the east and south-west coasts of Ireland. Aquatic Invasions 1: 91-96.

Minchin, D., Floerl, O., Savini, D. and Occhipinti-Ambrogi, A. 2006. Small craft and the spread of exotic species. In: Davenport, J. L. and Davenport, J. (ed.), Environmental Pollution 10: The Ecology of Transportation: managing mobility for the environment. pp. chapt. 6: 99-118.

Minchin, D. and Gollasch, S. 2003. Fouling and ships' hulls: how changing circumstances and spawning events may result in the spread of exotic species. Biofouling 19: 111-122.

Miwata, K., Chiba, T., Horii, R., Yamada, L., Kubo, A., Miyamura, D., Satoh, N. and Satou, Y. 2006. Systematic analysis of embryonic expression profiles of zinc finger genes in Ciona intestinalis. Dev.  Biol. 292: 546-554.

Monniot, F. and Monniot, C. 2004. A new species of Plurellidae (Ascidiacea : Phlebobranchia) from Papua New Guinea. Zootaxa 423: 1–8.

Monniot, F. and Monniot, C. 2006. A deep water Ascidia (Ascidiidae, Tunicata) from the tropical western Pacific. Zootaxa 1168: 43–49.

Monniot, F. and Monniot, C. 2006. Ascidians (Polyclinidae, Pseudodistomidae and Polycitoridae) from the western Indian Ocean. Zoosystema 28: 113-156.

Munro, E., Robin, F. and Lemaire, P. 2006. Cellular morphogenesis in ascidians: how to shape a simple tadpole. Curr. Opin. Genet. Dev. 16: 399-405.

Nakamura, Y., Makabe, K. W. and Nishida, H. 2006. The functional analysis of Type I postplasmic/PEM mRNAs in embryos of the ascidian Halocynthia roretzi. Dev. Genes & Evol. 216: 69-80.

Nohara, M., Nishida, M. and Nishikawa, T. 2005. New complete mitochondrial DNA sequence of the lancelet Branchiostoma lanceolatum (Cephalochordata) and the identity of this species' sequences. Zool. Sci. 22: 671-674.

Nyholm, S. V., Passegue, E., Ludington, W. B., Voskoboynik, A., Mitchel, K., Weissman, I. L. and De Tomaso, A. W. 2006. fester, A candidate allorecognition receptor from a primitive chordate. Immunity 25: 163-173.

Ogasawara, M., Nakazawa, N., Azumi, K., Yamabe, E., Satoh, N. and Satake, M. 2006. Identification of thirty-four transcripts expressed specifically in hemocytes of Ciona intestinalis and their expression profiles throughout the life cycle. DNA Res. 13: 25-35.

Ogawa, M., Kuramochi, T., Takayama, S., Tanimoto, D. and Naganuma, T. 2005. Inferring the feeding habit of the deep-sea 'big mouth' ascidian tunicate, Megalodicopia hians, by fatty acid analysis. Aquatic Ecosystem Health & Management 8: 185-193.

Ohtsuka, Y. and Okamura, Y. 2006. Voltage-dependent calcium influx mediates maturation of myofibril arrangement in ascidian larval muscle. Dev.  Biol. epub:

Ooishi, S. 2006. Two species of Botryllophilus (Copepoda: Cyclopoida) living in compound ascidians, and a revision of female morphotype A of the genus. J. Crust. Biol. 26: 23-47.

Pakhomov, E. A., Dubischar, C. D., Strass, V., Brichta, M. and Bathman, U. V. 2006. The tunicate Salpa thompsoni ecology in the Southern Ocean. I. Distribution, biomass, demography and feeding ecophysiology. Mar. Biol . 149: 609-623.

Pasini, A., Amiel, A., Rothbacher, U., Roure, A., Lemaire, P. and Darras, S. 2006. Formation of the ascidian epidermal sensory neurons: insights into the origin of the chordate peripheral nervous system. PLoS Biol. 4: e225.

Passamaneck, Y. J., Di Gregorio, A., Papaioannou, V. E. and Hadjantonakis, A. K. 2006. Live imaging of fluorescent proteins in chordate embryos: from ascidians to mice. Microsc. Res. Tech. 69: 160–167.

Patalano, S., Pruliere, G., Prodon, F., Paix, A., Dru, P., Sardet, C. and Chenevert, J. 2006. The aPKC-PAR-6-PAR-3 cell polarity complex localizes to the centrosome attracting body, a macroscopic cortical structure responsible for asymmetric divisions in the early ascidian embryo. J. Cell Sci. 119: 1592-1603.

Pechenik, J. A. 2006. Larval experience and latent effects—metamorphosis is not a new beginning. Integr. Comp. Biol. 46: 323-333.

Pennati, R., Groppelli, S., Zega, G., Biggiogero, M., De Bernardi, F. and Sotgia, C. 2006. Toxic effects of two pesticides, Imazalil and Triadimefon, on the early development of the ascidian Phallusia mammillata (Chordata, Ascidiacea). Aquatic Toxicol. 79: 205–212.

Perez-Portela, R., Duran, S., Estoup, A. and Turon, X. 2006. Polymorphic microsatellite loci isolated from the Atlanto-Mediterranean colonial ascidian Pycnoclavella sp (Ascidiacea, Tunicata). Mol. Ecol. Notes 6: 518-520.

Prodon, F., Chenevert, J. and Sardet, C. 2006. Establishment of animal-vegetal polarity during maturation in ascidian oocytes. Dev. Biol. 290: 297-311.

Raineri, M. 2006. Are protochordates chordates? Biol. J. Linn. Soc. 87: 261-284.

Ramsey, I. S., Moran, M. M., Chong, J. A. and Clapham, D. E. 2006. A voltage-gated proton-selective channel lacking the pore domain. Nature epub:

Rocha, R. M., Faria, S. B. and Moreno, T. R. 2005. Ascidians from Bocas del Toro, Panama. I. Biodiversity. Caribb. J. Sci. 41: 600-612.

Rocha, R. M. and Kremer, L. P. 2005. Introduced ascidians in Paranaguá Bay, Paraná, southern Brazil. Revista Brasileira de Zool. 22: 1170–1184.

Rosner, A., Paz, G. and Rinkevich, B. 2006. Divergent roles of the DEAD-box protein BS-PL10, the urochordate homologue of human DDX3 and DDX3Y proteins, in colony astogeny and ontogeny. Dev. Dyn. epub:

Saito, H., Mimura, K., Doi, A., Inoue, E., Kawai, K. and Imabayashi, H. 2005. Variations in body size of the lancelet Branchiostoma belcheri at different depths in the Seto Inland Sea: effect of food supply on the growth rate. Zool. Sci. 22: 1181-1189.

Sakabe, E., Tanaka, N., Shimozono, N., Gojobori, T. and Fujiwara, S. 2006. Effects of U0126 and fibroblast growth factor on gene expression profile in Ciona intestinalis embryos as revealed by microarray analysis.  Dev. Growth & Differ. 48: 391-400.

Salvador-Recatalà, V., Gallin, W. J., Abbruzzese, J., Ruben, P. C. and Spencer, A. N. 2006. A potassium channel (Kv4) cloned from the heart of the tunicate Ciona intestinalis and its modulation by a KChIP subunit. J. Exp. Biol. 209: 731-747.

Sanamyan, K. E. and Sanamyan, N. P. 2006. Deep-water ascidians (Tunicata: Ascidiacea) from the northern and western Pacific. J. Nat. Hist. 40: 307-344.

Sardet, C., Dumollard, R. and Mcdougall, A. 2006. Signals and calcium waves at fertilization. Semin. Cell Dev. Biol. 17: 223-225.

Satou, Y., Hamaguchi, M., Takeuchi, K., Hastings, K. E. and Satoh, N. 2006. Genomic overview of mRNA 5'-leader trans-splicing in the ascidian Ciona intestinalis. Cell Tiss. Res. 34: 3378-3388.

Scippa, S., De Candia, A., Groppelli, S. and De Vincentiis, M. 2006. Hatching enzyme immunolocalization during embryonic development of the ascidians Ciona intestinalis and Phallusia mammillata. Invert. Repro. & Dev. 49: 121-123.

Shenkar, N. and Monniot, F. 2006. A new species of the genus Botryllus (Ascidiacea) from the Red Sea. Zootaxa 1256: 11-19.

Shi, W., Levine, M. and Davidson, B. 2005. Unraveling genomic regulatory networks in the simple chordate, Ciona intestinalis. Genome Res. 15: 1668-1674.

Shiba, K., Marian, T., Krasznai, Z., Baba, S. A., Morisawa, M. and Yoshida, M. 2006. Na(+)/Ca(2+) exchanger modulates the flagellar wave pattern for the regulation of motility activation and chemotaxis in the ascidian spermatozoa. Cell Motil. Cytoskel. 63: 623-632.

Shimazaki, A., Sakai, A. and Ogasawara, M. 2006. Gene expression profiles in Ciona intestinalis stigmatal cells: insight into formation of the ascidian branchial fissures. Dev. Dyn. 235: 562-569.

Shirae-Kurabayashi, M., Nishikata, T., Takamura, K., Tanaka, K. J., Nakamoto, C. and Nakamura, A. 2006. Dynamic redistribution of vasa homolog and exclusion of somatic cell determinants during germ cell specification in Ciona intestinalis. Development 133: 2683-2693.

Shoguchi, E., Kawashima, T., Satou, Y., Hamaguchi, M., Sin, I. T., Kohara, Y., Putnam, N., Rokhsar, D. S. and Satoh, N. 2006. Chromosomal mapping of 170 BAC clones in the ascidian Ciona intestinalis. Genome Res. 16: 297-303.

Sierro, N., Kusakabe, T., Park, K. J., Yamashita, R., Kinoshita, K. and Nakai, K. 2006. DBTGR: a database of tunicate promoters and their regulatory elements. Nucleic Acids Res. 34: D552-D555.

Simoes-Costa, M. S., Vasconcelos, M., Sampaio, A. C., Cravo, R. M., Linhares, V. L., Hochgreb, T., Yan, C. Y., Davidson, B. and Xavier-Neto, J. 2005. The evolutionary origin of cardiac chambers. Dev. Biol. 277: 1-15.

Strathmann, R. R., Kendall, L. R. and Marsh, A. G. 2006. Embryonic and larval development of a cold adapted Antarctic ascidian. Polar Biol. 29: 495-501.

Sunanaga, T., Saito, Y. and Kawamura, K. 2006. Postembryonic epigenesis of Vasa-positive germ cells from aggregated hemoblasts in the colonial ascidian, Botryllus primigenus. Dev. Growth & Differ. 48: 87-100.

Swalla, B. J. 2006. Building divergent body plans with similar genetic pathways. Heredity epub 26 July: 1-9.

Takimoto, N., Kusakabe, T., Horie, T., Miyamoto, Y. and Tsuda, M. 2006. Origin of the vertebrate visual cycle: III. Distinct distribution of RPE65 and beta-carotene 15,15'-monooxygenase homologues in Ciona intestinalis. Photochem. Photobiol. epub:

Takimoto, N., Kusakabe, T. and Tsuda, M. 2006. Origin of the vertebrate visual cycle double dagger. Photochem. Photobiol. epub:

Tassy, O., Daian, F., Hudson, C., Bertrand, V. and Lemaire, P. 2006. A quantitative approach to the study of cell shapes and interactions during early chordate embryogenesis. Curr. Biol. 16: 345-358.

Tatian, M., Antacli, J. C. and Sahade, R. 2005. Ascidians (Tunicata, Ascidiacea): species distribution along the Scotia Arc. Scientia Marina 69 suppl. 2: 205-214.

Thiel, M. and Gutow, L. 2005. The ecology of rafting in the marine environment. II. The rafting organisms and community. Oceanogr. Mar. Biol. Ann. Rev. 43: 279-418.

Tiozzo, S., Ballarin, L., Burighel, P. and Zaniolo, G. 2006. Programmed cell death in vegetative development: Apoptosis during the colonial life cycle of the ascidian Botryllus schlosseri. Tiss. & Cell 38: 193-201.

Tönnesson, K., Maar, M., Vargas, C., Møller, E. F., Satapoomin, S., Zervoudaki, S., Christou, E., Ciannakourou, A., Sell, A., Petersen, J. K., Nielsen, T. G. and Tiselius, P. 2005. Grazing impact of Oikopleura dioica and copepods on an autumn plankton community. Mar. Biol. Res. 1: 365-373.

Tsemel, A., Spanier, E. and Angel, D. L. 2006. Benthic communities of artificial structures: effects of mariculture in the Gulf of Aqaba (Eilat) on development and bioaccumulation. Bull. Mar. Sci. 78: 103-113.

Turon, X., Lopez-Legentil, S. and Banaigs, B. 2005. Cell types, microsymbionts, and pyridoacridine distribution in the tunic of three color morphs of the genus Cystodytes (Ascidiacea, Polycitoridae). Invert. Biol. 124: 355–369.

Uddin, J., Ueda, K., Siwu, E. R., Kita, M. and Uemura, D. 2006. Cytotoxic labdane alkaloids from an ascidian Lissoclinum sp.: Isolation, structure elucidation, and structure-activity relationship. Bioorg. & Med. Chem. 14: 6954-6961.

Ushimaru, Y., Konno, A., Kaizu, M., Ogawa, K., Satoh, N. and Inaba, K. 2006. Association of a 66 kDa homolog of Chlamydomonas DC2, a subunit of the outer arm docking complex, with outer arm dynein of sperm flagella in the ascidian Ciona intestinalis. Zool. Sci. 23: 679-687.

Vienne, A. and Pontarotti, P. 2006. Metaphylogeny of 82 gene families sheds a new light on chordate evolution. Int. J. Biol. Sci. 2: 32-37.

Wada, H., Okuyama, M., Satoh, N. and Zhang, S. 2006. Molecular evolution of fibrillar collagen in chordates, with implications for the evolution of vertebrate skeletons and chordate phylogeny. Evol. & Dev. 8: 370-377.

Wada, S., Hamada, M. and Satoh, N. 2006. A genomewide analysis of genes for the heat shock protein 70 chaperone system in the ascidian Ciona intestinalis. Cell Stress & Chaperones 11: 23-33.

Whitaker, M. 2006. Calcium at fertilization and in early development. Physiol. Rev. 86: 25-88.

Worby, C. A. and Dixon, J. E. 2005. Phosphoinositide phosphatases: emerging roles as voltage sensors? Molec. Interventions 5: 274-277.

Yamada, L. 2006. Embryonic expression profiles and conserved localization mechanisms of pem/postplasmic mRNAs of two species of ascidian, Ciona intestinalis and Ciona savignyi. Dev.  Biol. 296: 524-536.

Yokobori, S. I., Kurabayashi, A., Neilan, B. A., Maruyama, T. and Hirose, E. 2006. Multiple origins of the ascidian-Prochloron symbiosis: Molecular phylogeny of photosymbiotic and non-symbiotic colonial ascidians inferred from 18S rDNA sequences. Molec. Phylogenet. Evol. 40 (1): 8-19.

Yoshinaga, M., Ueki, T., Yamaguchi, N., Kamino, K. and Michibata, H. 2006. Glutathione transferases with vanadium-binding activity isolated from the vanadium-rich ascidian Ascidia sydneiensis samea. Biochim. Biophys. Acta 1760: 495-503.

Zega, G., Thorndyke, M. C. and Brown, E. R. 2006. Development of swimming behaviour in the larva of the ascidian Ciona intestinalis. J. Exp. Biol. 209: 3405-3412.

Zeller, R. W., Virata, M. J. and Cone, A. C. 2006. Predictable mosaic transgene expression in ascidian embryos produced with a simple electroporation device. Dev. Dyn. 235: 1921-1932.

Zeng, L., Jacobs, M. W. and Swalla, B. J. 2006. Coloniality has evolved once in stolidobranch ascidians. Integr. Comp. Biol. 46: 255-268.