Oriented cell divisions in the extending germband of Drosophila
Oriented cell divisions in the extending germband of Drosophila
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DOI：
10.1242/dev.004911
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发表时间：
2007-09-01
期刊：
影响因子：
4.6
通讯作者：
Vincent, Jean-Paul
中科院分区：
文献类型：
--
作者：
da Silva, Sara Morais;Vincent, Jean-Paul
组织伸长是形态发生的一般特征。一个例子是胚带的延伸，这发生在果蝇的早期胚胎发生过程中。在胚胎的前部，伸长是细胞插入的过程。在这项研究中，我们遵循细胞的行为在后面的延伸生殖带。我们发现，在这个区域，细胞分裂主要是纵向取向的快速阶段的伸长。抑制细胞分裂可防止后部区域的纵向变形，并导致伸长速率和程度的总体降低。因此，在斑马鱼胚胎中，细胞嵌入和定向细胞分裂共同促进组织伸长。我们还表明，当节段模式受到损害时，纵向分裂的比例会降低，例如，在甚至跳过（eve）突变体中。由于在前胚带的极化细胞嵌入也需要节段性图案，因此可能会对这两个过程使用共同的极化线索。尽管在鱼胚胎中，这两种机制都需要经典的平面细胞极性（PCP）途径，但胚带延伸和定向细胞分裂在缺乏凌乱（dsh）的胚胎中正常进行，dsh是PCP途径的关键组成部分。因此，一种平面偏振的替代方法必须在胚胎表皮中起作用。
Tissue elongation is a general feature of morphogenesis. One example is the extension of the germband, which occurs during early embryogenesis in Drosophila. In the anterior part of the embryo, elongation follows from a process of cell intercalation. In this study, we follow cell behaviour at the posterior of the extending germband. We find that, in this region, cell divisions are mostly oriented longitudinally during the fast phase of elongation. Inhibiting cell divisions prevents longitudinal deformation of the posterior region and leads to an overall reduction in the rate and extent of elongation. Thus, as in zebrafish embryos, cell intercalation and oriented cell division together contribute to tissue elongation. We also show that the proportion of longitudinal divisions is reduced when segmental patterning is compromised, as, for example, in even skipped (eve) mutants. Because polarised cell intercalation at the anterior germband also requires segmental patterning, a common polarising cue might be used for both processes. Even though, in fish embryos, both mechanisms require the classical planar cell polarity (PCP) pathway, germband extension and oriented cell divisions proceed normally in embryos lacking dishevelled (dsh), a key component of the PCP pathway. An alternative means of planar polarisation must therefore be at work in the embryonic epidermis.