Sefton M, Sánchez S, Nieto M A
Instituto Cajal, CSIC, Avenida Doctor Arce, 28002 Madrid, Spain.
Development. 1998 Aug;125(16):3111-21. doi: 10.1242/dev.125.16.3111.
The members of the Snail family of zinc-finger transcription factors have been implicated in the formation of distinct tissues within the developing vertebrate and invertebrate embryo. Two members of this family have been described in higher vertebrates, Snail (Sna) and Slug (Slu), where they have been implicated in the formation of tissues such as the mesoderm and the neural crest. We have isolated the mouse homologue of the Slu gene enabling us to analyse and compare the amino acid sequences and the patterns of expression of both Sna and Slu in the chick and mouse. We have detected features in the sequences that allow the unequivocal ascription of any family member to the Sna or Slu subfamilies and we have observed that, during early stages of development, many of the sites of Slu and Sna expression in the mouse and chick embryo are swapped. Later in development, the sites of expression of Slu and Sna are conserved between these two species. These data, together with the data available in other species, lead us to propose that Slu and Sna arose as a duplication of an ancestor gene and that an extra duplication in the fish lineage has given rise to two Sna genes. Furthermore, several early sites of Slu and Sna expression have been swapped in the avian lineage. Our analysis of the Snail family may also shed new light on the origin of the neural crest.
锌指转录因子Snail家族的成员与发育中的脊椎动物和无脊椎动物胚胎内不同组织的形成有关。在高等脊椎动物中已描述了该家族的两个成员，即Snail（Sna）和Slug（Slu），它们与中胚层和神经嵴等组织的形成有关。我们分离出了Slu基因的小鼠同源物，这使我们能够分析和比较Sna和Slu在鸡和小鼠中的氨基酸序列及表达模式。我们在序列中检测到了一些特征，这些特征使得能够明确地将任何家族成员归为Sna或Slu亚家族，并且我们观察到，在发育早期，小鼠和鸡胚胎中Slu和Sna的许多表达位点是互换的。在发育后期，Slu和Sna的表达位点在这两个物种之间是保守的。这些数据，连同其他物种的现有数据，使我们提出Slu和Sna是作为一个祖先基因的复制而产生的，并且鱼类谱系中的一次额外复制产生了两个Sna基因。此外，在鸟类谱系中，Slu和Sna的几个早期表达位点已经互换。我们对Snail家族的分析也可能为神经嵴的起源提供新的线索。
