Abstract 347: Zebrafish Insertional Cardiac (ZIC) Mutants: a Living Genomic Resource for Cardiac Biology
The human genome encodes about 20,000 genes and only a fraction of them are expressed in the heart. We hypothesized that annotation of this category of genes may facilitate our understanding of cardiac development and function. Recently, we reported a pilot insertional mutagenesis screening in zebrafish to annotate cardiac gene functions using a gene-break transposon (GBT). It demonstrated the feasibility of generation of a Zebrafish Insertional Cardiac (ZIC) mutant collection by screening gene expression in the embryonic heart. Here, we report an alternative strategy to identify cardiac mutants based on adult heart expression, and explore the application of expanded ZIC lines for understanding cardiac biology. From 203 GBT lines, we identified 34 lines with detectable expression in the dissected adult hearts. Various expression levels of the tagged genes were detected in embryonic hearts. Based on their tissue-specific expression, the candidate ZIC lines can be grouped into myocardium lines, endocardium lines, or both. Based on their subcellular expression, myocardium ZIC lines can be further categorized into sarcomeric lines, mitochondrial lines, and/or nucleic lines. Phenotypic analysis is being conducted to identify recessive mutants including embryonic lethal lines. We will present the current status of our ZIC collection, and discuss its application as a genomic resource platform for elucidating cardiac biology. Our data suggest that ~15% genes in the whole genome might have detectable cardiac expression. The sensitivity of screening for cardiac genes at adult stage is higher than that at embryonic stage (34/203 versus 18/322). We plan to expand the ZIC collection by screening 1,000 GBT lines that are being generated at Mayo Clinic. It is expected that this living mutant collection of cardiac genes will open doors to systematic annotation of novel cardiac genes and forward cardiac mutagenesis screening.
- © 2013 by American Heart Association, Inc.