FUNCTION OF ENDOTHELIN FAMILY IN NEURAL CREST DEVELOPMENT TEM

小鼠突变致死斑点（ls）编码血管活性肽 内皮素3（EDN 3）和花斑基因座编码其受体， 内皮素受体B（EDNRB）。突变纯合子小鼠， 这些基因表现出无神经节细胞巨克隆和白色斑点的外套， 缺乏神经嵴来源的肠神经节和黑素细胞， 结肠和皮肤的受影响部分。为了理解 这些基因在黑素细胞发育中的作用， 杂交以确定这些基因表达的时间 相对于突变和正常胚胎中的其他神经嵴标记物。我们 这两种基因在小鼠发育的早期就表达了， 神经嵴衍生细胞的胚胎发育和表达 在不同的神经嵴突变体中改变了模式我们已经确定 外源性添加EDN3改变促进增殖， 我们在体外系统中观察黑素细胞的分化， 开发我们已经发现EDN3可以成功地取代TPA， 系统并导致黑素细胞增加50倍。我们发现 在相关家族成员（EDN1和EDN2）中，只有EDN1可以 在该测定中取代EDN3。我们还表明， EDN3依赖于神经嵴上其受体EDNRB的存在 细胞通过使用化学抑制剂。

The mouse mutant lethal spotting (ls) encodes the vasoactive peptide endothelin 3 (EDN3) and the piebald (s) locus encodes its receptor, endothelin receptor B (EDNRB). Mice homozygous for mutations in either of these genes exhibit aganglionic megaclon and a white spotted coat due to the lack of neural-crest derived enteric ganglia and melanocytes in affected portions of the colon and skin. In order to understand the role of these genes in melanocyte development, we are using in situ hybridization to determine the time that these genes are expressed relative to other neural crest markers in mutant and normal embryos. We have shown that both genes are expressed very early during mouse embryonic development in neural crest derived cells and expression patterns are altered in various neural crest mutants. We have determined that exogenously added EDN3 alters promotes proliferation and differentiation of melanocytes in an in vitro system that we have developed. We have found that EDN3 can successfully replace TPA in this system and results in a 50 fold increase in melanocytes. We have found that of the related family members (EDN1 and EDN2) only EDN1 can substitute for EDN3 in this assay. We have also shown that the effect of EDN3 is dependent upon the presence of its receptor EDNRB on neural crest cells by using chemical inhibitors.