Brönner G, Chu-LaGraff Q, Doe C Q, Cohen B, Weigel D, Taubert H, Jäckle H
Max-Planck-Institut für biophysikalische Chemie, Abteilung Molekulare Entwicklungsbiologie, Göttingen, Germany.
Nature. 1994 Jun 23;369(6482):664-8. doi: 10.1038/369664a0.
Much of our present knowledge of the biological processes involved in pattern formation in Drosophila is derived from segmentation analysis. Comparatively little is known about the genetic requirement and mechanisms underlying the formation and separation of germ layers by morphogenetic movements during gastrulation. Here we show that the Drosophila gene huckebein (hkb), a member of the gap-gene class of segmentation genes, is required for germ-layer formation at blastoderm. Absence of the hkb product, an Sp1/egr-like zinc-finger protein, causes the ectodermal and mesodermal primordia to expand at the expense of endoderm anlagen. Conversely, ectopic expression of hkb inhibits the formation of the major gastrulation fold which gives rise to the mesoderm and prevents normal segmentation in the ectoderm. Thus, hkb is necessary for endoderm development and its activity defines spatial limits within the blastoderm embryo in which the germ layers are established.
我们目前对果蝇模式形成所涉及的生物学过程的许多认识都来自于体节分析。对于原肠胚形成期间通过形态发生运动形成和分离胚层的遗传需求和机制，我们了解得相对较少。在这里，我们表明果蝇基因huckebein（hkb）是一种体节基因中的间隙基因类成员，它在胚盘形成胚层时是必需的。hkb产物是一种Sp1/egr样锌指蛋白，其缺失会导致外胚层和中胚层原基扩张，以内胚层原基为代价。相反，hkb的异位表达会抑制形成中胚层的主要原肠胚褶皱的形成，并阻止外胚层的正常体节形成。因此，hkb对于内胚层发育是必需的，其活性在胚盘胚胎内定义了建立胚层的空间界限。
