Differential Roles of Broadly Expressed Transcription Factors in Early Cardiac Cell Specification

All developmental processes are well-orchestrated and coordinated by numerous developmentally associated genes that determine the various cell fates and tissue differentiation. The transcriptional regulation early in life is extremely dynamic and the genes implicated at those early time points work cooperatively forming multi-directional gene networks, which remain a subject of ongoing research attempting to describe their mechanisms. Previous studies have shown the gene regulation dynamics in cardiac cells, after gastrulation, but these regulatory events remained unclear before the onset of gastrulation. In this study, we focused on the role of Odd-paired (Opa/ZIC3) and Suppressor of Hairless (Su(H)/RBPJ), in regulating cardiac genes before the onset of gastrulation. Our results showed that unlike the non-significant changes in expression levels between nc14C and nc14D in Opa knockdown embryos, expression patterns were changed. Additionally, our results showed that Opa regulates slp and odd before gastrulation, which confirms our hypothesis of Opa regulating important genes for cardiac cell specification during cellularization. Our findings suggested that, in low levels of Opa, Su(H) inhibits Opa activity, but at later stages, when Opa levels are elevated, Opa overcomes Su(H) repressing role and acts as an activator. These observations enhance our understanding of cell specification and may offer insights into how this regulatory mechanism influences the onset of cardiac impairments by disrupting key cardiac target genes.