Cloning and Characterization of Genes Specifically Expressed in Haploid Germ Cells

精子发生是一个复杂的分化过程，涉及许多有趣的生物学现象，如精原细胞的增殖和分化、单倍体生殖细胞的减数分裂和产生以及在通往精子的过程中的形态发生。分离在睾丸中特异表达的基因以及在生殖细胞分化的不同阶段中特异表达的基因为理解精子发生提供了新的线索，消减克隆将有效地分离生殖细胞特异的新基因。17日龄小鼠睾丸未见单倍体生殖细胞分化。如果我们能从这种17天龄的成人睾丸中减去一个文库，就可以分离出完全来自单倍体生殖细胞的ConA克隆。由于制备这类消减文库的技术改进，已分离到许多在单倍体生殖细胞中特异表达的cDNA克隆，通过对这些基因功能的研究，必将在精子发生的研究乃至控制生殖细胞分化的复杂过程的新的临床应用方面取得重大进展。

Spermatogenesis is a complex differentiation process involving many interesting phenomena that are biologically important, such as spermatogonial proliferation and differentiation, meiosis and generation of haploid germ cells and morphogenesis on the way to the sperm. Isolation of genes specifically expressed in testes and also specifically expressed in different steps of germ cell differentiation sheds new light on understanding the spermatogenesis.Subtraction cloning would be effective to isolate novel genes that were germ-cell-specific. No haploid germ cell differentiation occurs to the testes of 17 days old mouse testis. If we can subtract a cDNA library of such 17 days old testes from adult testits, cONA clones derived solely from the haploid germ cells could be isolated. Because of technical improvement for preparing this type of subtraction cDNA library, many cDNA clones specifically expressed in haploid germ cells have been isolated.By the characterization of the function of these genes we will surely make great progress on the study of spermatogenesis and even on new clinical applications that will control the complicated processes of the germ cell differentiation.