Molecular Mechanism of Functional Regulation of Spermatiogenic Cells by Interaction with Other Somatic Cells and Eggs

为了阐明其他体细胞和卵子对小鼠雄配子的功能调控，我们研究了小鼠精子发生、精子成熟、精子从子宫到输卵管的转运和受精过程中的细胞相互作用。获得了以下实验结果：（1）从小鼠睾丸cDNA文库中鉴定了编码睾丸特异性poly（A）聚合酶（TPAP）的cDNA克隆，TPAP是一种负责生精细胞中预先存在的mRNA的细胞质聚腺苷酸化的候选分子。缺乏TPAP的雄性小鼠导致精子发生的停滞和生精细胞凋亡的增加。在单倍体圆形精子细胞阶段之前的凋亡增加可能不是由于生精停滞的直接影响，而是由于通过支持细胞将斑点信号转导到早期生精细胞。(2)In小鼠，两种不同的ADAM 1亚型。ADAM 1a和ADAM 1b在睾丸中产生。ADAM 1a限制 ...更多信息 dly位于睾丸生殖细胞的内质网内，而附睾精子仅在质膜上含有ADAM 1b。小鼠ADAM 1a的缺失导致雄性不育，因为精子通过子宫输卵管连接处从子宫迁移到输卵管的能力严重受损。然而，ADAM 1a缺陷小鼠的附睾精子能够在体外受精卵丘完整，透明卵完整的卵子，尽管卵丘细胞的延迟分散和减少的粘附/结合到透明卵。这些结果表明，ADAM 1a/ADAM 2 fertilin复合物可以调节特定的精子蛋白，包括ADAM 3，这是参与迁移到输卵管，在卵丘细胞的分散，并在结合到透明质酸，从内质网的睾丸生殖细胞到细胞表面的选择性运输。（3）精子PH-20缺乏的雄性小鼠，尽管卵丘细胞从卵丘团中分散的能力降低，但仍具有生育能力。精子提取物的蛋白质印迹分析显示，除PH-20外，其他透明质酸酶可能存在于精子顶体中。这些数据提供了PH-20至少在小鼠中对于受精不是必需的证据，并且表明其他透明质酸酶可能在精子穿透卵丘细胞层和/或卵透明质层中起重要作用，可能与PH-20合作。少

To elucidate the functional regulation of mouse male gamete by other somatic cells and eggs, we have examined the cell interaction in spermatogenesis, sperm maturation, sperm transit from uterus to oviduct, and fertilization in mouse. The following experimental results have been obtained(1)cDNA clones encoding a testis-specific poly(A) polymerase, TPAP, a candidate molecule responsible for cytoplasmic polyadenylation of pre-existing mRNAs in spermatogenic cells have been identified from a mouse testis cDNA library. Male mice lacking TPAP resulted in the arrest of spermatogenesis and in the increase of apoptosis in spermatogenic cells. The increased apoptosis before the stage of haploid round spermatids may be due not to direct effects of the spermatogenic arrest, but to a transduction of the spoptotic signals to the earlier stages of spermatogenic cells through Sertoli cells.(2)In mouse, two different isoforms of ADAM1. ADAM1a and ADAM1b, are produced in the testis. ADAM1a is restricte … More dly localized within the endoplasmic reticulum of testicular germ cells, whereas epididymal sperm contain only ADAM1b on the plasma membrane. The loss of mouse ADAM1a resulted in the male infertility because of the severely impaired ability of sperm to migrate from the uterus into oviduct through the uterotubal junction. However, epididymal sperm of ADAM1a-deficient mice were capable of fertilizing the cumulus-intact, zona pellucida-intact eggs in vitro, despite the delayed dispersal of cumulus cells and the reduced adhesion/binding to the zona pellucida. These results suggest that the ADAM1a/ADAM2 fertilin complex may regulate the selective transport of specific sperm proteins including ADAM3, which are involved in the migration into the oviduct, in the dispersal of cumulus cells, and in the binding to the zona pellucida, from the endoplasmic reticulum of testicular germ cells onto the cell surface.(3)Male mice lacking sperm PH-20 were still fertile, in spite of a reduced ability to disperse cumulus cells from the cumulus mass. Western blot analysis of sperm extracts revealed the presence of other hyaluronidase(s), except PH-20, presumably within the sperm acrosome. These data provide evidence that PH-20 is not essential for fertilization at least in the mouse, and suggest that the other hyaluronidase(s) may play an important role in the sperm penetration through the cumulus cell layer and/or the egg zona pellucida, possibly in cooperation with PH-20. Less