Schröder C, Tautz D, Seifert E, Jäckle H
Max-Planck-Institut für Entwicklungsbiologie, Abt. Biochemie, Tübingen, FRG.
EMBO J. 1988 Sep;7(9):2881-7. doi: 10.1002/j.1460-2075.1988.tb03145.x.
The Drosophila gap gene hunchback (hb) is required for the establishment of the anterior segment pattern of the embryo, and also for a small region of the posterior segment pattern. The hb gene encodes two transcripts from two promoters which show a differential regulation, although they code for the same protein product. The 3.2-kb transcript is expressed during oogenesis and forms an anterior-posterior gradient during the early stages of development. The first zygotic expression of hb during cleavage stages 11-12 is due to the 2.9-kb transcript. Its expression is under the control of the anterior pattern organizer gene bicoid (bcd) and it appears to be necessary and sufficient for the anterior segmentation. The 3.2-kb transcript is expressed again at syncytial blastoderm stage in the anterior yolk nuclei, as well as in an anterior stripe which is posteriorly adjacent to the domain of the 2.9-kb transcript, and as a posterior stripe. Using hb-promoter/lacZ fusion gene constructs in combination with germ line transformation, we have delimited a regulatory region for the 2.9-kb transcript to approximately 300 bp upstream of the site of transcription initiation and show that this region is sufficient to confer the full regulation by bcd.
果蝇缺口基因驼背（hb）对于胚胎前段模式的建立以及后段模式的一个小区域来说是必需的。hb基因从两个启动子编码两种转录本，尽管它们编码相同的蛋白质产物，但表现出差异调控。3.2kb的转录本在卵子发生过程中表达，并在发育早期形成前后梯度。hb在卵裂阶段11 - 12的首次合子表达归因于2.9kb的转录本。其表达受前段模式组织者基因双胸（bcd）的控制，并且对于前段分割似乎是必要且充分的。3.2kb的转录本在合胞体胚盘阶段在前部卵黄核中再次表达，以及在与2.9kb转录本区域后部相邻的前部条带中以及作为后部条带表达。使用hb - 启动子/ lacZ融合基因构建体并结合种系转化，我们已将2.9kb转录本的调控区域界定在转录起始位点上游约300bp处，并表明该区域足以赋予bcd的完全调控。
