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Biology subjects

Frain, M.

Publications and source records attributed to Frain, M..

2 recordsLinked to original sources

Endothelin 3 and T-type Ca2+ channels drive enteric neural crest cell calcium activity, contractility and migration

Enteric neural crest cells (ENCCs) colonize the gut during embryogenesis and migration defects give rise to Hirschsprung disease (HD). Mutations in GDNF/RET and EDN3/EDNRB are known to be causal in HD. Here, we show that migrating ENCCs in mice exhibit endogenous EDN3/EDNRB-gated calcium activity, mediated by chloride channels, T-type Ca2+ channels and inositol trisphosphate-sensitive intracellular-store release. We find that inhibiting Ca2+ activity results in ENCC migration defects, while exciting it promotes migration by increasing ENCC contractility and traction force to the extracellular matrix. Our study demonstrates that embryonic endothelin-mediated neural crest migration and adult endothelin-mediated vasoconstriction is one and the same phenomenon, taking place in different cell types. Our results suggest a functional link between rare mutations of CACNA1H (the gene encoding CaV3.2) and HD, and pave the way for understanding neurocristopathies in terms of neural crest cell bioelectric activity deficits.

developmental biology↗

Dynamic fate map of hindbrain rhombomeres in zebrafish

Understanding of the morphogenetic processes that underlie the patterning of the vertebrate hindbrain requires establishment of rhombomere (r) cell lineages. Using long term in vivo two-photon imaging of zebrafish transgenic lines and automated image processing tools, we provide a method to reconstruct the r2-r6 lineage trees from the onset of gastrulation through early neurulation. We provide a dynamic fate map of hindbrain patterning at single-cell resolution. We show that rhombomere progenitor domains are aligned along the anteroposterior (AP) and dorsoventral (DV) axes as early as the shield stage. Rhombomere progenitor domains show a segmental organization, parallel to the blastoderm margin that predicts the future AP order of hindbrain. The DV organization of rhombomeres is set by the segregation of the progenitors along the DV axis of the embryo. Progenitors located at the dorsal/medial part of the blastoderm form the ventral domain of the rhombomeres while the lateral progenitors constitute the dorsal part. Our study sheds light on the clonal origin of individual rhombomeres, spatial and temporal patterns of cell division and migration of rhombomere progenitors throughout the early steps of hindbrain morphogenesis.

developmental biology↗