Investigating the Effects of FGF Signaling on Prdm1 Expression in Ciona intestinalis

Abstract

Understanding how gene regulation is controlled is one of the most fundamental factors to understand how embryos development and disruptions to gene regulation can result in diseases. Prdm1 transcription factors are known to be important in Ciona development as well as in human immunologic responses. However, the gene regulatory interactions remain unclear in both models. In this study I used reporter assays and HCR in situ hybridization to understand Prdm1 expression within early Ciona. I found that for 2 of the Ciona Prdm1 genes, Prdm1-r.a/b, expression is upregulated by FGF signaling. ETS and GATA motifs, highly conserved genomic regulators, are clustered in the enhancer regions of Prdm1-r.a/b and were sufficient in driving expression and response to FGF, establishing them as important avenues of study for understanding the regulation and functional role of Prdm1 in Ciona and other organisms. Further work would be needed to done to further understand the temporal regulation and differences between Prdm1-r.a and b. Based on analysis of minimal enhancer regions in both Prdm1 paralogs, I propose the pioneer factor Foxa.a as a possible temporal regulator for Prdm1-r.a in Ciona.