Affiliation:
1. Biochemistry and Microbiology, University of Victoria Victoria BC, Canada V8W 2Y2
Abstract
We have examined regulation of neurogenesis by Delta/Notch signaling in sea urchin embryos. At gastrulation neural progenitors enter S-phase coincident with expression of Sp-SoxC. We used a BAC (bacterial artificial chromosome) containing GFP knocked into the Sp-SoxC locus to label neural progenitors. Live imaging and immunolocalizations indicate that Sp-SoxC-expressing cells divide producing pairs of adjacent cells expressing GFP. Over an interval of about 6 h, one cell fragments, undergoes apoptosis, and expresses high levels of activated Caspase3. A Notch reporter indicates that Notch signaling is activated in cells adjacent to cells expressing Sp-SoxC. Inhibition of γ-secretase, injection of Sp-Delta morpholinos, or CRISPR/Cas9-induced mutation of Sp-Delta results in supernumerary neural progenitors and neurons. Interfering with Notch signaling increases neural progenitor recruitment and pairs of neural progenitors. Thus, Notch signaling restricts the number of neural progenitors recruited and regulates the fate of progeny of the asymmetric division. We propose a model in which localized signaling converts ectodermal and ciliary band cells to neural progenitors that divide asymmetrically to produce a neural precursor and an apoptotic cell.
Funder
Natural Sciences and Engineering Research Council of Canada
Publisher
The Company of Biologists
Subject
Developmental Biology,Molecular Biology
Cited by
31 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献