Nieto M A, Bennett M F, Sargent M G, Wilkinson D G
Laboratory of Eukaryotic Molecular Genetics, National Institute for Medical Research, The Ridgeway, Mill Hill, London, UK.
Development. 1992 Sep;116(1):227-37. doi: 10.1242/dev.116.1.227.
The genetic analysis of dorsoventral patterning in Drosophila has identified a zinc-finger gene, snail, that is required for mesoderm formation. The cloning and nuclease protection analysis of a Xenopus homologue of this gene has suggested a possible role in the mesoderm of vertebrates. Here, we describe the cloning of a murine homologue of snail, Sna, and in situ hybridisation studies of its developmental expression. Sequence analysis reveals substantial conservation of the second to fifth zinc fingers, but not of the first zinc finger in the Sna gene. Expression occurs in the ectoplacental cone, parietal endoderm, embryonic and extraembryonic mesoderm, in neural crest and in condensing precartilage. Based on the timing and spatial restriction of expression in embryonic mesoderm, we suggest that Sna might be required for the early development of this tissue, as is the case for its Drosophila counterpart. In addition, we propose that Sna might have an analogous role in the development of neural crest. The expression in condensing precartilage indicates that this gene also has a later function in chondrogenesis.
对果蝇背腹模式形成的遗传分析已鉴定出一个锌指基因——蜗牛基因，它是中胚层形成所必需的。对该基因非洲爪蟾同源物的克隆和核酸酶保护分析表明，它在脊椎动物中胚层可能发挥作用。在此，我们描述了蜗牛基因的小鼠同源物Sna的克隆及其发育表达的原位杂交研究。序列分析显示，Sna基因的第二至第五个锌指高度保守，但第一个锌指并非如此。其表达出现在外胎盘锥、壁内胚层、胚胎和胚外中胚层、神经嵴以及正在凝聚的前软骨中。基于其在胚胎中胚层表达的时间和空间限制，我们认为Sna可能像其果蝇对应物一样，是该组织早期发育所必需的。此外，我们提出Sna在神经嵴发育中可能具有类似作用。在正在凝聚的前软骨中的表达表明，该基因在软骨形成后期也发挥作用。
