Chicken protocadherin-1 functions to localize neural crest cells to the dorsal root ganglia during PNS formation

Abstract

In vertebrate embryos, neural crest cells emerge from the dorsal neural tube and migrate along well defined pathways to form a wide diversity of tissues, including the majority of the peripheral nervous system (PNS). Members of the cadherin family of cell adhesion molecules play key roles during the initiation of migration, mediating the delamination of cells from the neural tube. However, a role for cadherins in the sorting and re-aggregation of the neural crest to form the PNS has not been established. We report the requirement for a protocadherin, chicken protocadherin-1 (Pcdh1), in neural crest cell sorting during the formation of the dorsal root ganglia (DRG). In embryos, cPcdh1 is highly expressed in the developing DRG, where it co-localizes with the undifferentiated and mitotically active cells along the perimeter. Pcdh1 can promote cell adhesion in vivo and disrupting Pcdh1 function in embryos results in fewer neural crest cells localizing to the DRG, with a concomitant increase in cells that migrate to the sympathetic ganglia. Furthermore, those cells that still localize to the DRG, when Pcdh1 is inhibited, are no longer found at the perimeter, but are instead dispersed throughout the DRG and are now more likely to differentiate along the sensory neuron pathway. These results demonstrate that Pcdh1-mediated cell adhesion plays an important role as neural crest cells coalesce to form the DRG, where it serves to sort cells to the mitotically active perimeter.

CXCR4 Controls Ventral Migration of Sympathetic Precursor Cells

“…Our shRNA data are also consistent with a role for CXCR4 signaling in regulating cadherin expression since ectopic expression of CXCR4 increased the compaction of SG. It has been shown that the protocadherin pcdh-1 plays a key role in positioning cells within either the neural core versus perimeter of chick DRGs (Bononi et al, 2008).…”

Regulation of cadherin expression in the chicken neural crest by the Wnt/ β-catenin signaling pathway

“…9,37 One possible explanation for the lack/very low levels of cadherin-11 expression in the neural crest-derived DRG is that as the neural crest cells coalesce to form the DRG, the decrease of cadherin-11 expression by cells that have stopped migrating may assist with segregation of the cells forming the DRG from the surrounding cadherin-11-positive mesenchyme. Overall, the expression pattern of cadherin-11 in the chicken embryo is comparable with characterization from other organisms.…”

Expression of delta‐protocadherins in the spinal cord of the chicken embryo

“…To clone the cDNA fragments of delta-Pcdhs, specific primers were designed with the Lasergene software (DNASTAR, Madison, WI), based on published sequences (Pcdh1, Bononi et al, 2008;Pcdh19, Tai et al, 2010) and predicted sequences (Pcdh7, Pcdh8, Pcdh9, Pcdh17, and Pcdh18) that were downloaded from the NCBI website (http://www.ncbi.nlm.nih.gov). Table 1 lists the primers used and information for sequence accession.…”

“…The expression of some delta-Pcdhs in the spinal cord has been described in the zebrafish (Pcdh9 and Pcdh17, Liu et al, 2009;Biswas and Jontes, 2009;Pcdh18, Kubota et al, 2008;Aamar and Dawid, 2008;Pcdh19, Liu et al, 2010), but relatively little is known for higher vertebrates (Pcdh1 in chicken and mouse, Bononi et al, 2008;Redies et al, 2008;Pcdh10 in chicken, Nakao et al, 2005; Pcdh19 in mouse, Gaitan and Bouchard, 2006). In the present study, we cloned and identified eight deltaPcdhs of chicken (Pcdh1, Pcdh7, Pcdh8, Pcdh9, Pcdh10, Pcdh17, Pcdh18, and Pcdh19) and analyzed their spatiotemporal expression patterns during spinal cord development in the chicken embryo.…”