Bimodal function of chromatin remodeler < i > Hmga1 < /i > in neural crest induction and Wnt-dependent emigration

During gastrulation, neural crest cells are specified at the neural plate border, as characterized byPax7 expression. Using single-cell RNA sequencing coupled with high resolutionin situ hybridization to identify novel transcriptional regulators, we show that chromatin remodelerHmga1 is highly expressed prior to specification and maintained in migrating chick neural crest cells. Temporally-controlled CRISPR-Cas9-mediated knockouts uncovered two distinct functions ofHmga1 in neural crest development. At the neural plate border,Hmga1 regulates Pax7-dependent neural crest lineage specification. At premigratory stages, a second role manifests whereHmga1 loss reduces cranial crest emigration from the dorsal neural tube independent ofPax7. Interestingly, this is rescued by stabilized ß-catenin, thus implicatingHmga1 as a canonical Wnt activator. Together, our results show thatHmga1 functions in a bimodal manner during neural crest development to regulate specification at the neural plate border, and subsequent emigration from the neural tube via canonical Wnt signaling.
Source: eLife - Category: Biomedical Science Tags: Developmental Biology Source Type: research