FUNCTION OF ENDOTHELIN FAMILY IN NEURAL CREST DEVELOPMENT TEM

小鼠突变致死斑点(Ls)编码血管活性多肽 内皮素3(EDN3)和花椒(S)基因座编码其受体， 内皮素受体B(EDNRB)。任何一种基因突变的纯合子小鼠 这些基因中有无神经节细胞的巨克隆和白色斑点被毛 神经脊源性肠神经节和黑素细胞的缺乏 受影响的部分结肠和皮肤。为了理解这一角色 在黑素细胞发育的这些基因中，我们使用了原位 杂交以确定这些基因表达的时间 相对于突变胚胎和正常胚胎中的其他神经脊标记。我们 已经证明这两个基因在小鼠体内很早就表达了 神经沟来源细胞的胚胎发育及其表达 在各种神经脊突变体中，模式会发生变化。我们已经决定 外源添加的EDN3改变并促进增殖和 黑素细胞在体外系统中的分化 发展起来的。我们发现EDN3在这方面可以成功地取代TPA 并导致黑素细胞增加50倍。我们发现了 亲缘家庭成员(EDN1和EDN1)中只有EDN1可以 可替代本试验中的EDN3。我们还表明， Edn3依赖于其受体ednrb在神经脊上的存在。 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.