Cohen S M, Brönner G, Küttner F, Jürgens G, Jäckle H
Max-Planck-Institut für Entwicklungsbiologie, Tübingen, FRG.
Nature. 1989 Mar 30;338(6214):432-4. doi: 10.1038/338432a0.
The spatial organization of the Drosophila embryo depends on the activity of three axial pattern-forming systems. In addition to the anterior-posterior and dorsal-ventral systems that organize the segmented body plan, a proximal-distal pattern-forming system is required to provide positional information for the developing limbs. The development of both the larval and adult limbs depends directly on the activity of the Distal-less gene. Genetic analysis has shown that Distal-less functions as a developmental switch that is required to promote the development of limb structures above the evolutionary ground-state of body wall. Here we provide genetic evidence that indicates a graded requirement for Distal-less activity during limb development. Reduction of this activity has a global effect on pattern formation in the limb. The molecular structure of the Distal-less locus indicates that the gene encodes a homoeodomain-containing protein which is therefore likely to specify limb development through differential regulation of subordinate genes.
果蝇胚胎的空间组织依赖于三个轴向模式形成系统的活动。除了组织分节身体计划的前后和背腹系统外，还需要一个近端-远端模式形成系统来为发育中的肢体提供位置信息。幼虫和成虫肢体的发育都直接依赖于无翅基因的活动。遗传分析表明，无翅基因作为一个发育开关，是促进肢体结构发育高于体壁进化基态所必需的。在这里，我们提供了遗传证据，表明在肢体发育过程中对无翅基因活动存在分级需求。这种活动减少对肢体模式形成有全局影响。无翅基因座的分子结构表明，该基因编码一种含同源异型域的蛋白质，因此可能通过对下属基因的差异调节来指定肢体发育。
