Cohen S M
Lehrstuhl für Genetik, Universität München, FRG.
Nature. 1990 Jan 11;343(6254):173-7. doi: 10.1038/343173a0.
Limb development in Drosophila requires the activity of a proximo-distal pattern-forming system, in addition to the antero-posterior and dorso-ventral pattern-forming systems that subdivide the embryo. Several lines of genetic evidence indicate that the Distal-less gene plays an important part in specifying proximo-distal positional information. The Distal-less locus encodes a homoeodomain-containing protein, which suggests that Distal-less may exert its activity through differential regulation of subordinate genes. The spatially restricted pattern of Distal-less expression allows direct visualization of the limb primordia during early embryogenesis. Here I report that from their inception, the leg primordia span the parasegment boundary. The segment polarity gene wingless seems to have a key part in defining the positions at which leg primordia will develop along the antero-posterior axis of the embryo. This analysis allows a direct molecular visualization of the compartments that subdivide the limb primordia into discrete developmental domains.
果蝇的肢体发育除了需要将胚胎进行细分的前后轴和背腹轴模式形成系统的活动外，还需要一个近远轴模式形成系统的活动。几条遗传学证据表明，无翅基因在指定近远轴位置信息方面起着重要作用。无翅基因座编码一种含同源结构域的蛋白质，这表明无翅基因可能通过对下游基因的差异调控来发挥其作用。无翅基因表达的空间受限模式使得在胚胎早期发育过程中能够直接观察到肢体原基。在此我报告，从其起始阶段起，腿部原基就跨越了副节边界。节段极性基因无翅似乎在确定腿部原基将沿着胚胎前后轴发育的位置方面起着关键作用。这种分析使得能够直接从分子层面观察将肢体原基细分为离散发育域的区室。
