Henrique D, Tyler D, Kintner C, Heath J K, Lewis J H, Ish-Horowicz D, Storey K G
Developmental Genetics, Imperial Cancer Research Fund, London, UK.
Genes Dev. 1997 Mar 1;11(5):603-15. doi: 10.1101/gad.11.5.603.
In vertebrate embryos, the precursor cells of the central nervous system (CNS) are induced by signaling from the organizer region. Here we report the isolation of a novel vertebrate achaete-scute homolog, cash4, which is expressed in the presumptive posterior nervous system in response to such signaling. cash4 is first expressed in epiblast cells flanking the late-phase organizer (Hensen's node), which retains its ability to induce cash4 during regression to the caudal end of the embryo. We show that these node-derived signals can be mimicked in vivo by the activity of fibroblast growth factor (FGF). We demonstrate that cash4 can substitute for the achaete/scute genes in the fly and that it also has proneural activity in vertebrate embryos. Together these results suggest that cash4 functions as a proneural gene downstream of node-derived signals (including FGF) to promote the formation of the neural precursors that will give rise to the posterior CNS in the chick embryo.
在脊椎动物胚胎中，中枢神经系统（CNS）的前体细胞是由组织者区域发出的信号诱导产生的。在此，我们报告了一种新型脊椎动物achaete-scute同源物cash4的分离，它在推定的后神经系统中响应此类信号而表达。cash4首先在晚期组织者（亨氏结）两侧的上胚层细胞中表达，在向胚胎尾端退缩过程中，该组织者仍保留诱导cash4的能力。我们表明，这些来自结的信号在体内可被成纤维细胞生长因子（FGF）的活性模拟。我们证明cash4可替代果蝇中的achaete/scute基因，并且它在脊椎动物胚胎中也具有原神经活性。这些结果共同表明，cash4作为一种原神经基因，在来自结的信号（包括FGF）下游发挥作用，以促进神经前体细胞的形成，这些细胞将产生鸡胚的后中枢神经系统。
