Wolff C, Sommer R, Schröder R, Glaser G, Tautz D
Zoologisches Institut, Universität München, Germany.
Development. 1995 Dec;121(12):4227-36. doi: 10.1242/dev.121.12.4227.
The segmentation gene hunchback (hb) plays a central role in determining the anterior-posterior pattern in the Drosophila embryo. We have cloned the homologue of hb from the flour beetle Tribolium and show that, on the basis of its expression pattern, most of its functions seem to be conserved between these two species. Like Drosophila, Tribolium has a maternal hb expression that appears to be under translational control by a factor at the posterior pole of the embryo. The maternal expression is followed by a zygotic expression in the region of the developing head and thoracic segments. During germ band extension, a posterior expression domain appears that is likely to be homologous to the posterior blastoderm expression of hb in Drosophila. These observations suggest that hb may have the same functions in early Drosophila and Tribolium development, despite the different types of embryogenesis in these two species (long versus short germ development). One differing aspect of hb expression in Tribolium concerns a structure that is not present in Drosophila, namely the serosa. An hb expression domain at the anterior pole precisely demarcates the border between the extraembryonic serosa and the embryonic field in the Tribolium embryo at an early stage, and hb protein remains expressed in the serosa cells until the end of embryogenesis.
分节基因驼背蛋白（hb）在果蝇胚胎前后模式的决定中起着核心作用。我们从面粉甲虫赤拟谷盗中克隆了hb的同源物，并表明，基于其表达模式，这两个物种之间其大部分功能似乎是保守的。与果蝇一样，赤拟谷盗也有母体hb表达，这种表达似乎受胚胎后极一个因子的翻译控制。母体表达之后是在发育中的头部和胸段区域的合子表达。在胚带延伸期间，出现了一个后部表达结构域，它可能与果蝇中hb在胚盘后部的表达同源。这些观察结果表明，尽管这两个物种的胚胎发生类型不同（长胚与短胚发育），但hb在果蝇和赤拟谷盗早期发育中可能具有相同的功能。赤拟谷盗中hb表达的一个不同方面涉及果蝇中不存在的一种结构，即浆膜。在早期，赤拟谷盗胚胎前极的一个hb表达结构域精确地标定了胚外浆膜与胚胎区域之间的边界，并且hb蛋白在浆膜细胞中一直表达到胚胎发育结束。
