A new transgenic Xenopus reporter line reveals dynamic expression of snail2 during cranial neural crest development

Abstract

During vertebrate embryogenesis, the cranial neural crest (CNC) is induced at the neural plate border (NPB) and subsequently migrate and differentiate into various cells and tissues. In Xenopus, the transcription factor Snail2 is induced at the NPB by canonical Wnt signaling and is required for CNC induction and migration, but the roles of Snail2 at later stages remain unclear. To monitor CNC development in live embryos, we generated a transgenic X. tropicalis line expressing Green Fluorescent Protein(GFP) driven by the snail2 promoter. Using whole‐genome sequencing, we mapped the transgene insertion to a noncoding region. Live imaging of the transgenic embryos reveals that snail2 is expressed in pre‐migratory and migrating CNC but is lost in CNC cells that have arrived at their destinations. However, snail2 is re‐expressed during CNC differentiation in all CNC derivatives that were examined. Defects in CNC differentiation, in addition to induction and migration, can be readily detected using this transgenic snail2 reporter line. Finally, comparison with a transgenic Wnt reporter line shows that Wnt signaling is consistently activated prior to snail2 expression, suggesting that the Wnt‐Snail2 axis may play important roles in multiple stages of CNC development. We are also developing a new transgenic line with a photoconvertible protein instead of GFP that can be used to monitor cell fate of various CNC branches for lineage tracing of CNC derivatives.Support or Funding InformationFunded by: NIH DE022813 and GM114105This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.