The PAF1 complex differentially regulates cardiomyocyte specification

►Zebrafish ctr9 mutants have a dramatic reduction in myocardial tissue. ►Ctr9 is part of the PAF1C, which also contains Paf1, Cdc73, Rtf1, and Leo1. ►The PAF1C regulates specification of cardiomyocytes from the lateral plate mesoderm. ►The PAF1C functions cell autonomously in cardiomyocyte specification.