Burkhart J G, Malling H V
National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Gamete Res. 1989 Apr;22(4):399-410. doi: 10.1002/mrd.1120220406.
In an electron microscopy study of abnormal spermatogenesis in mice, we have found that two discrete haploid nuclei may be located in a single spermatid cytoplasm after the second meiotic division. The spermatid continues to differentiate and forms a binucleate spermatozoon with both nuclei separately packaged within the sperm head. The Golgi apparatus of the double spermatid forms a single proacrosome that attaches to both nuclei. Apparently, one acrosomal structure differentiates to cover and compartmentalize the two haploid nuclei within the sperm head. Chromatin condensation appears normal. The head morphology and number of flagella vary in mature spermatozoa produced by this process. This work demonstrates one pathway by which polyploid spermatids continue to differentiate to spermatozoa after failure of cytoplasmic division or possibly cellular fusion.
在一项对小鼠异常精子发生的电子显微镜研究中，我们发现，在第二次减数分裂后，两个离散的单倍体细胞核可能位于单个精子细胞的细胞质中。精子细胞继续分化，形成一个双核精子，两个细胞核分别包裹在精子头部。双精子细胞的高尔基体形成一个单一的前顶体，附着在两个细胞核上。显然，一个顶体结构分化形成，覆盖并分隔精子头部内的两个单倍体细胞核。染色质浓缩看起来正常。通过这个过程产生的成熟精子中，头部形态和鞭毛数量各不相同。这项研究证明了多倍体精子细胞在细胞质分裂失败或可能的细胞融合失败后继续分化为精子的一条途径。
