Investigation On The Special Expression Of C-kit And C-myc In Gametogenesis And The Microstructure Of Spermatheca Of Loxoblemmus Doenitzi (Gryllidae)

In the long history of evolutionary process, Insecta becomes the biggest species group in animal kingdom, which makes up about 80 percent of the total living species. Depending on their powerful reproductive capacity, insects widely distribute on the earth. Studies of reproductive physiology can help us to further master the reproductive mechanisms and to make full use of so rich insect resource.In the present paper, some investigations on Loxoblemmus doenitzi ( Gryllidae ) are reported. In order to discover the meiosis of spermatomeres and spermiogenesis, slice-pressing method and improved phenol-fuchsin dyeing method are used. In the course of meiosis, primary spermatocytes directly enter metaphase II, not through telophase I and prophase II. In order to understand the mechanism of spermatozoa living in the spermatheca after copulation, Hematoxylin-Eosin dyeing method is used to discover the microstructure of the spermatheca by light microscope. The results show that, from inner to outer, like Oxya chinesis , the spermatheca of Loxoblemmus doenitzi also consists of six layers except that there is only one kind of secretory cell in the epidermis. The secretory product is alkalophilic and enters the spermathecal cavity through secretory tubules. It maybe create the very microenvironment for preserving spermatozoa and enabling them to develop.In order to study the regulatory mechanism in gametogenesis of Loxoblemmus doenitzi, the special expression of c-kit and c-myc is investigated by immunohistochemical method. The results show that there are Kit positive protein granules on the cellular membrane of spermatomeres from metaphase I to anaphase II, and in the head of mature spermatozoa not only in the testis but also in the spermatheca. However, Kit protein doesn' t exist in oogenesis after birth. Thereare also c-Myc positive protein granules in the spermatomeres from metaphase I to telophase II, in the spermatozoa and in the secretory cells of the spermatheca. c-Myc protein expresses not in the normal follicles, but in the follicular cells of the apoptotic ones.c-Kit is a receptor tyrosine protein kinase on the cellular membrane, while c-Myc is a transcription regulatory factor in the nucleus. In the signal transduction system, c-Kit is in the upstream as the stem cell factor(SCF) receptor, while c-Myc in the downstream as a target protein. The cyst cells enclosing spermatomeres maybe synthesize a kind of SCF-like protein, which can recognize specially the c-Kit receptor on the cellular membrane of spermatomeres. Then c-Kit is activated, dimerizing and autophosphorylating. At the same time, the tyrosine kinase domain of c-Kit is activized, which phosphorylates the proteins that have SH2 domain. At last, the related proteins and genes in meiosis are activated through a series of signal proteins, c-Myc is maybe one of the target proteins in the c-Kit/SCF signal transduction system. It activates or suppresses the target genes in forms of Myc-Max, Myc-Myc, Max-Max, Max-Mad or Max-Mxil. It can be concluded from the results that c-Myc plays an important role in regulating the related genes in meiosis of spermatomeres and spermiogenesis and in regulating the secretion of the secretory cells in the spermatheca.