The Role of neuropilins in cranial neural crest cell migration

Abstract

During vertebrate development, neural crest cells (NCCs) delaminate from the neural tube and migrate in a stereotypical pattern to specific destinations. In the cranial region, discrete NCC migratory streams invade the branchial arches to form facial structures and components of the nervous system, yet signaling mechanisms that produce the migration pattern are still unclear. We have previously identified a putative cranial NCC guidance cue, neuropilin‐1. When a neuropilin‐1 siRNA is used to knock down neuropilin‐1 expression in ovo, NCCs fail to fully invade the 2nd branchial arch and rostral branchial arch 3. Further analyses show that neuropilin‐1 siRNA transfected cells display fewer and shorter filopodia and a loss of cell polarity at the arch entrance, but are able to regain their migratory abilities when transplanted into younger embryos. Similar experiments using a neuropilin‐2 shRNA suggest that neuropilin‐2 does not influence the initial formation of the cranial NCC streams. We conclude that neuropilin‐1 acts as an invasion cue for a subset of cranial neural crest cells by influencing their ability to sense and react to their surrounding environment.This project was supported by the Stowers Institute for Medical Research.