GERM CELL-SPECIFIC MOLECULES OF SPERMATOZOA

哺乳动物精子发生过程中的基因表达正在被研究， 确定调节发育的内在和外在机制， 雄配子的功能。 被研究的基因表达独特， 生精细胞和/或在其发育的特定阶段。 它们编码已知蛋白质的生殖细胞特异性同种型，包括 参与细胞间糖酵解酶和蛋白质的基因 互动 例如，分离的cDNAs与RNA杂交， 甘油醛3-磷酸脱氢酶（Gapd-s）和己糖激酶表达 只存在于生精细胞中。 Gapd-s基因在减数分裂后表达， 单倍体精子细胞，而己糖激酶基因的表达开始于 粗线期精母细胞减数分裂。 葡萄糖对分离的 精子细胞，但是精子体外受精所需要的， 表明糖酵解发生独特的调节过程， 生精细胞 此外，甘露糖6-磷酸（M6 P）受体具有 在生精细胞上鉴定，并显示与携带M6 P的 支持细胞产生的配体。 多份成绩单 生殖细胞中的阳离子依赖性M6 P受体包括1.2和1.4 kb的mRNA 在体细胞中没有发现。 它们可能是由交替的 多聚腺苷酸化信号，一种用于粗线期精母细胞， 另一个在精子细胞中。 此外，还提供了编码层粘连蛋白结合的cDNA。 蛋白质已经被分离出来，并显示出识别1.3kb的转录本， 除了在体细胞中也看到的1.2kb转录物之外， 正在生产转基因小鼠，以检查表达的调节 这种谱系和阶段特异性基因及其产物的作用。 以前：精子的生殖细胞特异性分子

Gene expression during spermatogenesis in mammals is being examined to define intrinsic and extrinsic mechanisms regulating development and function of male gametes. Genes being studied are expressed uniquely in spermatogenic cells and/or during specific stages of their development. They code for germ cell specific isoforms of known proteins and include genes for glycolytic enzymes and proteins involved in cell-cell interaction. For example, cDNAS isolated hybridize with RNAs for glyceraldehyde 3-phosphate dehydrogenase (Gapd-s) and hexokinase expressed only in spermatogenic cells. The Gapd-s gene is expressed after meiosis in haploid spermatids, while expression of the hexokinase gene begins during meiosis in pachytene spermatocytes. Glucose is toxic to isolated spermatids but is required by spermatozoa for in vitro fertilization, indicating that unique regulatory processes occur for glycolysis in spermatogenic cells. In addition, mannose 6-phosphate (M6P) receptors have been identified on spermatogenic cells and shown to bind M6P-bearing ligands produced by Sertoli cells. Multiple transcripts for the cation-dependent M6P receptor in germ cells include 1.2 and 1.4 kb mRNAs not found in somatic cells. They probably arise from alternate polyadenylation signals, one being used in pachytene spermatocytes and the other in spermatids. Furthermore, a cDNA encoding a laminin-binding protein has been isolated and shown to recognize a 1.3 kb transcript in germ cells in addition to the 1.2 kb transcript also seen in somatic cells. Transgenic mice are being produced to examine the regulation of expression of such lineage- and stage- specific genes and the roles of their products. Formerly: Germ Cell-Specific Molecules of Spermatozoa