Ohkura H, Török T, Tick G, Hoheisel J, Kiss I, Glover D M
CRC Cell Cycle Genetics Group, Department of Anatomy and Physiology, The University of Dundee, UK.
J Cell Sci. 1997 Apr;110 ( Pt 8):945-54. doi: 10.1242/jcs.110.8.945.
Mutations in a gene (Klp38B) encoding a novel kinesin-like protein in Drosophila melanogaster lead to the formation of polyploid cells in the larval central nervous system and in the follicle cells of adult egg chambers. Some homozygous mutants survive to adulthood and also exhibit morphological defects indicative of abnormal cell cycle progression, including rough eyes, missing bristles, and abnormal abdominal cuticles. In larval brains, there is no accumulation of mitotic cells and the frequency of anaphase figures is comparable to wild type, suggesting that nuclear division is not affected. Such brains contain polyploid cells with metaphase and anaphase chromosomes associated with bipolar spindles. Such spindles have a number of unseparated centrosomes at their poles reflecting the degree of polyploidy of the cell. Follicle cells frequently contain two nuclei of roughly equal size. Taken together, we conclude that these Klp38B mutations lead to a failure of cytokinesis resulting in polyploidy, and discuss whether or not this is a direct effect of the mutation.
在果蝇中，一个编码新型驱动蛋白样蛋白的基因（Klp38B）发生突变，会导致幼虫中枢神经系统以及成年卵室的卵泡细胞中形成多倍体细胞。一些纯合突变体能够存活至成年期，并且还表现出表明细胞周期进程异常的形态缺陷，包括粗糙的眼睛、缺失刚毛以及异常的腹部表皮。在幼虫大脑中，没有有丝分裂细胞的积累，后期图像的频率与野生型相当，这表明核分裂未受影响。这样的大脑含有多倍体细胞，其具有与双极纺锤体相关的中期和后期染色体。这样的纺锤体在其两极有许多未分离的中心体，反映了细胞的多倍体程度。卵泡细胞经常含有两个大小大致相等的细胞核。综上所述，我们得出结论，这些Klp38B突变导致胞质分裂失败，从而产生多倍体，并讨论了这是否是突变的直接效应。
