Moss S B, Burnham B L, Bellvé A R
Department of Physiology and Biophysics, Harvard Medical School, Boston, Massachusetts.
Mol Reprod Dev. 1993 Feb;34(2):164-74. doi: 10.1002/mrd.1080340208.
The presence of lamin proteins in mouse spermatogenic cells has been examined by using an anti-lamin AC and an anti-lamin B antisera which recognize somatic lamins A and C, and somatic lamin B, respectively. Anti-lamin B binds to the nuclear periphery of all cell types examined, including Sertoli cells, primitive type A spermatogonia, preleptotene, leptotene, zygotene and pachytene spermatocytes, and round spermatids. In sperm nuclei, the antigenic determinants are localized to a narrow domain of the nucleus. However, after removing the perinuclear theca, anti-lamin B localizes to the entire nuclear periphery in a punctate pattern, suggesting that it is binding to determinants previously covered by the theca constituents. On immunoblots anti-lamin B reacts with a approximately 68 kD polypeptide in all germ cells and, to a lesser extent, with four additional polypeptides present only in meiotic and post-meiotic nuclear matrices. Anti-lamin AC also reacts with the perinuclear region of the somatic cells in the testes, in particular, those of the interstitium and also the Sertoli cells of the seminiferous epithelium. In contrast to anti-lamin B, anti-lamin AC does not bind to the germ cells at any stage of spermatogenesis. In addition, nuclear matrix proteins from isolated spermatogenic cells do not bind anti-lamin AC on immunoblots, suggesting the lack of reactivity is not due to the masking of any antigenic sites. These data demonstrate that germ cells contain lamin B throughout spermatogenesis, even during meiosis and spermiogenesis when the nuclear periphery lacks a distinct fibrous lamina.
通过使用分别识别体细胞型核纤层蛋白A和C以及体细胞型核纤层蛋白B的抗核纤层蛋白AC和抗核纤层蛋白B抗血清，研究了小鼠生精细胞中核纤层蛋白的存在情况。抗核纤层蛋白B与所有检测的细胞类型的核周边结合，包括支持细胞、原始A型精原细胞、前细线期、细线期、偶线期和粗线期精母细胞以及圆形精子细胞。在精子细胞核中，抗原决定簇定位于细胞核的一个狭窄区域。然而，去除核周膜后，抗核纤层蛋白B以点状模式定位于整个核周边，这表明它与先前被核周膜成分覆盖的决定簇结合。在免疫印迹中，抗核纤层蛋白B与所有生殖细胞中一条约68 kD的多肽发生反应，在较小程度上，还与仅存在于减数分裂和减数分裂后核基质中的另外四条多肽发生反应。抗核纤层蛋白AC也与睾丸中的体细胞的核周区域发生反应，特别是间质细胞以及生精上皮的支持细胞。与抗核纤层蛋白B不同，抗核纤层蛋白AC在精子发生的任何阶段都不与生殖细胞结合。此外，来自分离的生精细胞的核基质蛋白在免疫印迹中不与抗核纤层蛋白AC结合，这表明缺乏反应性不是由于任何抗原位点被掩盖。这些数据表明，生殖细胞在整个精子发生过程中都含有核纤层蛋白B，即使在减数分裂和精子形成过程中核周边缺乏明显的纤维状核纤层时也是如此。
