Gard D L, Hafezi S, Zhang T, Doxsey S J
Department of Biology, University of Utah, Salt Lake City.
J Cell Biol. 1990 Jun;110(6):2033-42. doi: 10.1083/jcb.110.6.2033.
Cycloheximide (500 micrograms/ml) rapidly arrests cleavage, spindle assembly, and cycles of an M-phase-specific histone kinase in early Xenopus blastulae. 2 h after cycloheximide addition, most cells contained two microtubule asters radiating from perinuclear microtubule organizing centers (MTOCs). In contrast, blastomeres treated with cycloheximide for longer periods (3-6 h) contained numerous microtubule asters and MTOCs. Immunofluorescence with an anticentrosome serum and EM demonstrated that the MTOCs in cycloheximide-treated cells were typical centrosomes, containing centrioles and pericentriolar material. We conclude that centrosome duplication continues in cycloheximide-treated Xenopus blastulae in the absence of a detectable cell cycle. In addition, these observations suggest that Xenopus embryos contain sufficient material to assemble 1,000-2,000 centrosomes in the absence of normal protein synthesis.
放线菌酮（500微克/毫升）能迅速阻止非洲爪蟾早期囊胚的卵裂、纺锤体组装以及M期特异性组蛋白激酶的循环。添加放线菌酮2小时后，大多数细胞含有两个从核周微管组织中心（MTOC）辐射出的微管星状体。相比之下，用放线菌酮处理较长时间（3 - 6小时）的卵裂球含有大量微管星状体和微管组织中心。用抗中心体血清进行免疫荧光和电镜观察表明，经放线菌酮处理的细胞中的微管组织中心是典型的中心体，含有中心粒和中心粒周围物质。我们得出结论，在没有可检测到的细胞周期的情况下，经放线菌酮处理的非洲爪蟾囊胚中中心体复制仍在继续。此外，这些观察结果表明，在没有正常蛋白质合成的情况下，非洲爪蟾胚胎含有足够的物质来组装1000 - 2000个中心体。
