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Analysis of spermatogenesis & meiosis using knockout mice

精子发生分析

基本信息

批准号：
09670010
负责人：
MORI Chisato
金额：
$ 1.92万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

The developmental program of spermatogenesis is a multi-step process which includes mitotic, meiotic, and post-meiotic phases characterized by dramatic shifts in the patterns of gene expression. We examined the function and expression pattern of spermatogenic cell specific genes (mHkl-s and Hsp 70-2) using knock-out mice.Unique type 1 hexokinase (HK1) mRNAs encode a spermatogenic cell-specific sequence region (SSR), but not the porin-binding domain (PBD) necessary for HK1 binding to porin on the outer mitochondrial membrane. Our study (Mori et al., 1998) determined the origin of the multiple Hkl-s transcripts in mouse spermatogenic cells and verified that they are translated in mouse spermatogenic cells. It also showed that a single mHkl gene encodes the mHkl transcripts of somatic cells and the mHkl-sa and mHkl-sb transcripts of spermatogenic cells, that alternative exons are used during mHkl gene expression in mouse spermatogenic cells, and that mHKl-S is translated in mouse spermato … More genic cells and is localized mainly with the fibrous sheath in the tail region.HSP70-2 is a unique member of the mouse 70-kDa heat shock protein family that is synthesized during meiosis in spermatogenic cells. Germ cells in male mice homozygous for a targeted mutation in the Hsp70-2 gene (Hsp7O-2^<-1->) arrest in development and undergo apoptosis at the end of the pachytene spermatocyte stage of meiotic prophase. However, cells with a putative acrosome were present occasionally in histological sections of the testes of juvenile and adult Hsp70-2^<-1-> mice. Our study (Mori et al., 1999) verified that acrosomes were present and investigated the relationship between acrosome formation and the process of meiosis. Our results indicate that not all pachytene spermatocytes in Hsp70-2^<-1-> mice arrest in meiosis, but may divide once or sometimes twice and begin acrosome formation and nuclear condensation. This demonstrates that some aspects of spermatid development can occur without the completion of meiosis in mice. Less

精子发生的发育程序是一个多步骤的过程，包括有丝分裂、减数分裂和减数分裂后阶段，其特征是基因表达模式的急剧变化。我们用敲除小鼠检测了生精细胞特异性基因（mHkl-s和hsp70 -2）的功能和表达模式。独特的1型己糖激酶（HK1） mrna编码生精细胞特异性序列区（SSR），但不编码HK1与线粒体外膜上的孔蛋白结合所必需的孔蛋白结合域（PBD）。我们的研究（Mori et al., 1998）确定了小鼠生精细胞中多个Hkl-s转录本的来源，并证实它们在小鼠生精细胞中被翻译。mHkl基因编码体细胞的mHkl转录本和生精细胞的mHkl-sa和mHkl-sb转录本，在小鼠生精细胞中mHkl-s基因的表达使用了不同的外显子，mHkl-s基因在小鼠精子细胞中被翻译，主要定位于尾区纤维鞘。HSP70-2是小鼠70 kda热休克蛋白家族的独特成员，在生精细胞减数分裂期间合成。由于Hsp70-2基因（Hsp70-2 ^<-1->）的靶向突变而纯合的雄性小鼠生殖细胞在减数分裂前期粗线精细胞阶段结束时发育停止并发生凋亡。然而，在幼年和成年Hsp70-2^<-1->小鼠睾丸的组织学切片中，偶尔存在假定的顶体细胞。我们的研究（Mori et al., 1999）证实了顶体的存在，并研究了顶体的形成与减数分裂过程的关系。我们的研究结果表明，Hsp70-2^<-1->小鼠的粗线精母细胞并不是全部停止减数分裂，但可能分裂一次或两次，并开始顶体形成和核凝聚。这表明，在小鼠中，精子发育的某些方面可以在没有完成减数分裂的情况下发生。少