V. Nataf et al., ENDOTHELIN-B RECEPTOR IS EXPRESSED BY NEURAL CREST CELLS IN THE AVIANEMBRYO, Proceedings of the National Academy of Sciences of the United Statesof America, 93(18), 1996, pp. 9645-9650
Disruptions of the genes encoding endothelin 3 (EDN3) and its receptor
endothelin-B receptor (EDNRB) in the mouse result in defects of two n
eural crest (NC)-derived lineages, the melanocytes, and the enteric ne
rvous system, To assess the mechanisms through which the EDN3/EDNRB si
gnaling pathway can selectively act on these NC derivatives, we have s
tudied the spatiotemporal expression pattern of the EDNRB gene in the
avian embryo, a model in which NC development has been extensively stu
died, For this purpose, we have cloned the quail homologue of the mamm
alian EDNRB cDNA. EDNRB transcripts are present in NC cells before and
during their emigration from the neural tube at all levels of the neu
raxis. At later developmental stages, the receptor remains abundantly
expressed in the peripheral nervous system including the enteric nervo
us system. In a previous study, we have shown that EDN3 enhances drama
tically the proliferation of NC cells when they are at the pluripotent
stage. We propose that the selective effect of EDN3 or EDNRB gene ina
ctivation is due to the fact that both melanocytes and enteric nervous
system precursors have to colonize large embryonic areas (skin and bo
wel) from a relatively small population of precursors that have to exp
and considerably in number. It is therefore understandable that a defi
cit in one of the growth-promoting pathways of NC cells has more delet
erious effects on long-range migrating cells than on the NC derivative
s which develop close to the neural primordium like the sensory and sy
mpathetic ganglia.