Klasterska I, Ramel C
Institute of Genetic and Cellular Toxicology, Wallenberg Laboratory, Stockholm, Sweden.
Genetica. 1990;81(2):89-98. doi: 10.1007/BF00226447.
Male meiosis in D. melanogaster cytologically follows the usual pattern, whereas in D. melanogaster and in D. virilis oocytes the chromosomes clump into a karyosphere at early meiotic prophase and remain so up to metaphase I. Male meiosis in D. virilis spermatocytes has an intermediate character: a part of the chromatin clumps together in a karyosphere at early prophase, whereas the other part of the chromatin remains diffuse all through prophase. At the end of prophase, the diffuse chromatin becomes integrated into the karyosphere before metaphase I. During the meiotic divisions the chromosomes have the same clumped aspect as those in Drosophila oocytes and thus differ strikingly from the dividing chromosomes in D. melanogaster spermatocytes. In D. virilis spermatocytes the nucleolus exhibits changes during the meiotic prophase that may be related to synthetical activities. The DNA specific staining with the fluorochrome DAPI reveals the existence of extrachromosomal DNA in the later prophase. Other striking differences in meiotic events between the two Drosophila species concern the centrioles and spermiogenesis.
黑腹果蝇的雄性减数分裂在细胞学上遵循通常的模式，而在黑腹果蝇和粗壮果蝇的卵母细胞中，染色体在减数分裂前期早期聚集成核球，并一直保持到中期 I。粗壮果蝇精母细胞的雄性减数分裂具有中间特征：一部分染色质在前期早期聚集成核球，而另一部分染色质在整个前期都保持弥散状态。在前期结束时，弥散的染色质在中期 I 之前整合到核球中。在减数分裂过程中，染色体与果蝇卵母细胞中的染色体一样呈现聚集状态，因此与黑腹果蝇精母细胞中正在分裂的染色体明显不同。在粗壮果蝇精母细胞中，核仁在减数分裂前期会发生变化，这可能与合成活动有关。用荧光染料 DAPI 进行的 DNA 特异性染色显示在后期前期存在染色体外 DNA。这两种果蝇在减数分裂事件中的其他显著差异涉及中心粒和精子发生。
