Zebrafish and Heart Defects

Using CRISPR screening and editing in zebrafish to understand the mechanisms of heart development and the genetics of congenital heart defects

Our long-term goal with this project is to achieve a precise understanding of the genetic and transcriptional mechanisms underlying early heart development. Our group has shown that Pbx and Meis homeodomain transcription factors are critical regulators of heart development in zebrafish. However, the mechanisms underlying Pbx/Meis function in heart development and congenital heart defects are not understood. We are using CRISPR genome editing to engineer mutations in zebrafish pbx and meis genes to determine their functions in heart development. We are particularly interested in understanding how Pbx and Meis factors regulate the differentiation of cardiomyocytes. Because the transcriptional regulation of cardiomyocyte differentiation is highly conserved, our zebrafish work will have relevance for human heart development and disease. We are one of the first labs to use CRISPR to demonstrate a function for a human SNP in zebrafish, a PBX gene SNP associated with congenital heart defects (https://doi.org/10.1242/dmm.035972). Our studies aim to improve our understanding of how transcriptional regulatory factors like Pbx and Meis contribute to heart development and congenital heart defects.

In addition, we are using CRISPR genome screening in zebrafish to test the functions of a new set of genes that have been implicated in human congenital heart defects. Recently our screening has identified several new genes required for zebrafish heart development. We are using protein-protein interaction networks to form hypotheses about how these new genes work with other known heart development genes. Our goal is to gain insight into the complex genetics of congenital heart defects.