Pattern formation in the imaginal wing disc of Drosophila melanogaster: fate map, regeneration and duplication.
Pattern formation in the imaginal wing disc of Drosophila melanogaster: fate map, regeneration and duplication.
复制标题
果蝇成虫翅盘的图案形成：命运图、再生和复制。
DOI：
--
复制
发表时间：
1975
期刊：
影响因子：
--
通讯作者：
P. Bryant
中科院分区：
文献类型：
--
作者：
P. Bryant
果蝇的翅盘碎片（图2）要么被注射到成熟的三龄幼虫体内进行立即变态，要么在成虫腹部培养7天，然后转移到幼虫体内进行变态。然后分析了在变态过程中分化的结构。利用第一组实验的结果构建了圆盘的精确命运图，利用第二组实验的结果确定了圆盘的再生性能。命运图（图7）显示了椎间盘两端推定的近端部分（胸膜、胸膜、背侧和腹侧铰链），以及两者之间推定的远端翼部分。在变态过程中，椎间盘上皮沿假定的翼缘折叠，使翅背、腹侧和铰链面对齐。与成体结构相比，翼面在命运图中所占的相对面积要小得多，而铰链部分所占的相对面积要大得多。一般来说，培养片段的行为符合这样的规则：当通过切割圆盘产生两个切面时，其中一个切面发生再生，另一个发生复制（图14）。有可能在椎间盘纵轴上确定一个水平，从这个水平向外再生。远离这一水平面的切割表面显示再生，而面对这一水平的切割表面则发生复制。对于横轴和两个对角线系列的切割，也发现了类似的行为。一些具有两个切割边缘的片段可以从一个边缘再生，同时从另一个边缘复制，而另一些片段可以同时从两个切割边缘再生。然而，具有四个切割边缘的碎片显示不完全再生，并且即使在其他实验的基础上可能期望在所有方向上再生，也有很高的复制倾向。
Fragments of the wing disc of Drosophila (fig. 2) were either injected into mature third instar larvae for immediate metamorphosis, or cultured in adult abdomens for seven days before being transferred to larvae for metamorphosis. The structures differentiated during metamorphosis were then analysed. The results of the first series of experiments were used to construct an accurate fate map of the disc, and those of the second series were used to determine the regenerative properties of the disc. The fate map (fig. 7) shows presumptive proximal parts (notum, pleura, and dorsal and ventral hinge) at the two ends of the disc, with presumptive distal wing parts in between. During metamorphosis the disc epithelium folds upon itself along the presumptive wing border, bringing dorsal and ventral wing and hinge surfaces into apposition. The wing surfaces occupy a much smaller relative area, and the hinge parts a much larger relative area, in the fate map than in the adult structure. The cultured fragments, in general, behaved in accordance with the rule that when two cut surfaces are created by cutting across the disc, regeneration occurs from one of the cut surfaces and duplication occurs from the other (fig. 14). It was possible to define a level in the longitudinal axis of the disc from which regeneration proceeds outwards. Cut surfaces facing away from this level show regeneration, while cut surfaces facing this level undergo duplication. Similar behavior was found for the transverse axis, and for two diagonal series of cuts. Some fragments with two cut edges could regenerate from one edge while duplicating from the other, whereas others could regenerate from two cut edges simultaneously. However, fragments with four cut edges showed incomplete regeneration, and a high tendency to duplicate even though regeneration in all directions might have been expected on the basis of the other experiments.