Mansir A, Justine J L
Laboratoire de Biologie parasitaire-Protistologie-Helminthologie, Muséum national d'histoire naturelle, Paris, France.
Mol Reprod Dev. 1996 Nov;45(3):332-41. doi: 10.1002/(SICI)1098-2795(199611)45:3<332::AID-MRD10>3.0.CO;2-0.
Nematode spermatozoa are amoeboid cells. In Caenorhabditis elegans and Ascaris suum, previous studies have reported that sperm motility does not involve actin, but, instead, requires a specific cytoskeletal protein, namely major-sperm-protein (MSP). In Heligmosomoides polygyrus, a species with large and elongate spermatids and spermatozoa, cell organelles are easily identified even with light microscopy. Electrophoresis of Heligmosomoides sperm proteins indicates that the main protein band has a molecular weight of about 15 kDa, as MSP in other nematodes, and is specifically labelled by an anti-MSP antibody raised against C. elegans MSP. A minor band at 43 kDa was specifically labelled by an anti-actin antibody. Reaction of anti-actin and anti-MSP antibodies is specific to, and restricted to, their respective targets. Actin and MSP localisation, studied by indirect immunofluorescence in male germ cells of Heligmosomoides polygyrus, are similar: spermatids show rows of dots, corresponding to the fibrous bodies, around an unlabelled central longitudinal core; spermatozoa are labelled strictly in an anterior crescent-shaped cap, at the opposite pole to the nucleus, which contains fibres of the MSP cytoskeleton. Phalloidin labelling shows that F-actin is present in spermatids, but absent in spermatozoa. Tropomyosin shows a distinct pattern in spermatids, but is located in the MSP and actin-containing cap in spermatozoa. It is hypothesized that actin plays a role in the shaping of the cell and in the arrangement of its organelles during nematode spermiogenesis, when MSP is present, in an inactive state, in the fibrous bodies. The concentration of actin and tropomyosin in the anterior cap is not compatible with previous theories about the MSP cytoskeleton, which is supposed to act in the absence of actin.
线虫精子是变形细胞。在秀丽隐杆线虫和猪蛔虫中，先前的研究报告称精子运动不涉及肌动蛋白，而是需要一种特定的细胞骨架蛋白，即主要精子蛋白（MSP）。在多枝海德线虫中，其精子细胞和精子较大且细长，即使在光学显微镜下也很容易识别细胞器。多枝海德线虫精子蛋白的电泳表明，主要蛋白带的分子量约为15 kDa，与其他线虫中的MSP一样，并且被针对秀丽隐杆线虫MSP产生的抗MSP抗体特异性标记。一条43 kDa的次要条带被抗肌动蛋白抗体特异性标记。抗肌动蛋白和抗MSP抗体的反应对其各自的靶标具有特异性且仅限于这些靶标。通过间接免疫荧光研究多枝海德线虫雄性生殖细胞中肌动蛋白和MSP的定位，结果相似：精子细胞在未标记的中央纵向核心周围显示出成排的点，对应于纤维体；精子仅在与细胞核相对的极的前新月形帽中被标记，该帽包含MSP细胞骨架的纤维。鬼笔环肽标记显示F-肌动蛋白存在于精子细胞中，但不存在于精子中。原肌球蛋白在精子细胞中呈现出不同的模式，但位于精子中含有MSP和肌动蛋白的帽中。据推测，在 nematode精子发生过程中，当MSP以无活性状态存在于纤维体中时，肌动蛋白在细胞形态塑造及其细胞器排列中发挥作用。前帽中肌动蛋白和原肌球蛋白的浓度与先前关于MSP细胞骨架的理论不相符，该理论认为MSP细胞骨架在没有肌动蛋白的情况下起作用。
