Rodman T C, Litwin S D, Romani M, Vidali G
J Cell Biol. 1979 Mar;80(3):605-20. doi: 10.1083/jcb.80.3.605.
A basic protein fraction, migrating as a single band in acetic acid-urea gel, distinct from histones, was isolated from mouse sperm collected from vasa deferentia and caudae epididymides and was used to immunize female rabbits. The presence of antibodies to the mouse sperm protein (MSP) in the rabbit antisera was demonstrated by a cytoimmunofluorescence procedure using the cells of origin of the antigenic protein, the mature mouse sperm. The specificity of the antisera was verified by fluid and gel precipitation tests and by crossed immunoelectrophoresis. The latter procedure demonstrated the presence of two antigen-antibody systems, consonant with earlier reports that the basic chromosomal protein of mouse sperm is heterogeneous. MSP antigen in situ was recognized by the specific antibodies of the rabbit antisera only after the smear of mature sperm was treated with either of two reducing agents: 2-mercaptoethanol or dithiothreitol. However, when the immunofluorescence procedure was applied to untreated smears of mouse testicular cells, spermatids of all stages from 1 to 14-15 were positive, while spermatocytes, stage 16 spermatids and spermatozoa were negative. After treatment of testes smears with reducing agent, only spermatocytes remained negative. Those observations indicate the following: (a) MSP is immunogenic in a heterologous species; (b) its antigenic sites are detectable in spermatozoa and spermatids of all stages, but not in primary spermatocytes; (c) those antigenic sites become masked at about stage 15 of spermiogenesis and may be unmasked by treatment with a reducing agent. The interpretation is made, therefore, that one or more components of MSP are assembled at the beginning of spermiogenesis and undergo an alteration in the final intratesticular stage of spermatid maturation. That alteration may be presumed to be the formation of disulfide linkages between the cysteine residues.
从小鼠输精管和附睾尾部采集的精子中分离出一种碱性蛋白组分，该组分在醋酸 - 尿素凝胶中呈单一泳带迁移，与组蛋白不同，并用其免疫雌性兔子。通过使用抗原蛋白的来源细胞即成熟小鼠精子进行细胞免疫荧光程序，证明了兔抗血清中存在针对小鼠精子蛋白（MSP）的抗体。通过液体和凝胶沉淀试验以及交叉免疫电泳验证了抗血清的特异性。后一种程序证明存在两个抗原 - 抗体系统，这与早期关于小鼠精子碱性染色体蛋白具有异质性的报道一致。仅在用两种还原剂之一：2 - 巯基乙醇或二硫苏糖醇处理成熟精子涂片后，兔抗血清的特异性抗体才能识别原位MSP抗原。然而，当将免疫荧光程序应用于未处理的小鼠睾丸细胞涂片时，从1到14 - 15阶段的所有精细胞均呈阳性，而精母细胞、16阶段精细胞和精子呈阴性。在用还原剂处理睾丸涂片后，只有精母细胞仍为阴性。这些观察结果表明：（a）MSP在异种动物中具有免疫原性；（b）其抗原位点在所有阶段的精子和精细胞中均可检测到，但在初级精母细胞中未检测到；（c）这些抗原位点在精子发生的大约15阶段被掩盖，并且可以通过用还原剂处理而被暴露。因此，可以推断MSP的一种或多种成分在精子发生开始时组装，并在精细胞成熟的最终睾丸内阶段发生改变。可以推测这种改变是半胱氨酸残基之间形成二硫键。
