Della N G, Senior P V, Bowtell D D
Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria, Australia.
Development. 1993 Apr;117(4):1333-43. doi: 10.1242/dev.117.4.1333.
The seven in absentia gene (sina) is required for formation of the R7 photoreceptor cell in the developing eye of Drosophila melanogaster. The sina protein contains a putative zinc finger domain and localises to the cell nucleus in Drosophila. We report here the identification of a family of genes in the mouse (designated Siah) with extensive sequence homology to Drosophila sina. The Siah genes fall into two main groups: Siah-1, which consists of four closely related members, two of which appear to be functional, and Siah-2, which contains a single functional member. The predicted Siah proteins show an unusually high degree of conservation with sina over the majority of their lengths, diverging significantly only at their amino terminal ends. The Siah-1 and Siah-2 genes are widely expressed at a low level in the embryo and adult. Analysis of Siah-2 by hybridisation histochemistry shows that it is expressed at a higher level in a restricted number of sites during development, including the olfactory epithelium, retina, forebrain and proliferating cartilage of developing bone. The striking degree of sequence homology observed between the Drosophila and murine genes implies strong conservation pressure on the Siah genes and suggests that they play a significant role in vertebrate development.
七缺失基因（sina）是黑腹果蝇发育中的眼睛里R7光感受器细胞形成所必需的。sina蛋白包含一个假定的锌指结构域，并且在果蝇中定位于细胞核。我们在此报告在小鼠中鉴定出一个与果蝇sina具有广泛序列同源性的基因家族（命名为Siah）。Siah基因分为两个主要组：Siah-1，由四个紧密相关的成员组成，其中两个似乎具有功能；以及Siah-2，包含一个单一的功能成员。预测的Siah蛋白在其大部分长度上与sina具有异常高的保守程度，仅在其氨基末端显著不同。Siah-1和Siah-2基因在胚胎和成年期广泛低水平表达。通过杂交组织化学对Siah-2的分析表明，它在发育过程中的有限数量位点上表达水平较高，包括嗅觉上皮、视网膜、前脑和发育中骨骼的增殖软骨。在果蝇和小鼠基因之间观察到的显著序列同源程度意味着对Siah基因有很强的保守压力，并表明它们在脊椎动物发育中起重要作用。
