A gene regulatory program controlling early Xenopus mesendoderm formation: Network conservation and motifs.
Germ layer formation is among the earliest differentiation events in metazoan embryos. In triploblasts, three germ layers are formed, among which the endoderm gives rise to the epithelial lining of the gut tube and associated organs including the liver, pancreas and lungs. In frogs (Xenopus), where early germ layer formation has been studied extensively, the process of endoderm specification involves the interplay of dozens of transcription factors. Here, we review the interactions between these factors, summarized in a transcriptional gene regulatory network (GRN). We highlight regulatory connections conserved between frog, fish, mouse, and human endodermal lineages. Especially prominent is the conserved role and regulatory targets of the Nodal signaling pathway and the T-box transcription factors, Vegt and Eomes. Additionally, we highlight network topologies and motifs, and speculate on their possible roles in development.
Department of Developmental and Cell Biology, Ayala School of Biological Sciences, University of California, Irvine, CA 92697, USA.
Rebekah M
RM
Charney
Department of Developmental and Cell Biology, Ayala School of Biological Sciences, University of California, Irvine, CA 92697, USA.
Kitt D
KD
Paraiso
Department of Developmental and Cell Biology, Ayala School of Biological Sciences, University of California, Irvine, CA 92697, USA.
Ira L
IL
Blitz
Department of Developmental and Cell Biology, Ayala School of Biological Sciences, University of California, Irvine, CA 92697, USA. Electronic address: kwcho@uci.edu.
Ken W Y
KWY
Cho
D000818:Animals; D002454:Cell Differentiation; D004707:Endoderm / Q000196:embryology*; D053263:Gene Regulatory Networks / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D014981:Xenopus / Q000235:genetics*; D029867:Xenopus Proteins / Q000235:genetics*
D014157:Transcription Factors; D029867:Xenopus Proteins
Endoderm; Evolutionary conservation; Gene regulatory network; Network motifs; Transcription factors; Xenopus