Murdoch J N, Eddleston J, Leblond-Bourget N, Stanier P, Copp A J
Neural Development Unit, University College London, UK.
Dev Genet. 1999;24(1-2):165-77. doi: 10.1002/(SICI)1520-6408(1999)24:1/2<165::AID-DVG15>3.0.CO;2-V.
Nhlh1 is a basic helix-loop-helix (bHLH) gene that has been implicated in mouse neurogenesis. Previous studies have shown it to be expressed in regions in which there are differentiating neurons during late embryonic and fetal development, but detailed studies of the role of Nhlh1 earlier in embryonic development have not been performed. In this paper, we examine the expression of Nhlh1 transcripts at early embryonic stages (E8.5-E10.5), at the onset of neurogenesis, and compare the pattern of expression with that of Islet-1, a marker of postmitotic neurons. We show that Nhlh1 is expressed in early postmitotic neurons but is down-regulated as these cells migrate from the ventricular zone. We have also determined the genomic structure of mouse Nhlh1 and have characterised the promoter sequence, as a first step towards identifying factors that may control Nhlh1 expression. Nhlh1 has been implicated previously as a candidate for the neural tube defect mutant loop-tail (Lp); here, we present sequence and expression data indicating that Nhlh1 is unlikely to be responsible for the Lp mutation.
Nhlh1是一种碱性螺旋-环-螺旋（bHLH）基因，与小鼠神经发生有关。先前的研究表明，它在胚胎后期和胎儿发育期间有分化神经元的区域表达，但尚未对Nhlh1在胚胎发育早期的作用进行详细研究。在本文中，我们研究了Nhlh1转录本在神经发生开始时的早期胚胎阶段（E8.5-E10.5）的表达，并将其表达模式与有丝分裂后神经元的标志物Islet-1的表达模式进行比较。我们发现Nhlh1在早期有丝分裂后神经元中表达，但随着这些细胞从脑室区迁移而被下调。我们还确定了小鼠Nhlh1的基因组结构并对启动子序列进行了表征，这是鉴定可能控制Nhlh1表达的因子的第一步。Nhlh1先前被认为是神经管缺陷突变体环尾（Lp）的候选基因；在此，我们提供的序列和表达数据表明Nhlh1不太可能是Lp突变的原因。
