Callaini G, Anselmi F
Department of Evolutionary Biology, University of Siena, Italy.
Exp Cell Res. 1988 Oct;178(2):415-25. doi: 10.1016/0014-4827(88)90410-7.
In the early Drosophila embryo, nuclear elongation occurs during cellularization of the syncytial blastoderm. This process is closely related to the presence of microtubular bundles forming a basket-like structure surrounding the nuclei. In immunofluorescence observations with antibodies against alpha-tubulin, the microtubules appear to radiate from two bright foci widely separated from each other. We used electron microscopy to show that these foci are true centrosomes constituted by daughter and parent centrioles orthogonally disposed and surrounded by pericentriolar electrondense material. The centrosomes may be observed in the apical region of the blastoderm cells from the beginning of cellularization until the reestablishment of the first postblastodermic mitosis, when they organize the spindle poles. Until this time the dimensions of the procentrioles remain unchanged. The significance of these results is discussed in relation to the known behavior of centrioles in the cell cycle.
在早期果蝇胚胎中，核伸长发生在合胞体胚盘细胞化过程中。这一过程与形成围绕细胞核的篮状结构的微管束的存在密切相关。在用抗α -微管蛋白抗体进行的免疫荧光观察中，微管似乎从彼此相距很远的两个明亮焦点放射状发出。我们利用电子显微镜表明，这些焦点是真正的中心体，由正交排列的子代和亲代中心粒构成，并被中心粒周围电子致密物质包围。从细胞化开始直到胚盘后第一次有丝分裂重新建立，在此期间胚盘细胞顶端区域都可观察到中心体，此时它们组织纺锤体极。在此之前，原中心粒的尺寸保持不变。结合中心粒在细胞周期中的已知行为对这些结果的意义进行了讨论。
