Genomics and Proteomics of the Reproductive System
(W549) EXPRESSION RESEARCH FOR A NOVEL HUMAN SPATA12 GENE AS A CANDIDATE TUMOR SUPPRESSOR GENE IN THE TESTIS.
Li, Dan1, Lu, Guangxiu2, 1 Hunan University, Changsha, China2 Central South University, Changsha, China
ABSTRACT- Spermatogenesis is a complex process of cell development and differentiation. It occurs in successive mitotic, meiotic, and post-meiotic phase. The unique differentiation mechanisms of spermatogenesis suggest the existence of germ cell specific molecules. In our previous study, a novel human testis-specific gene SPATA12 (GeneBank accession number AY221117) was identified using the digital differential display program. Here, SYBR real-time RT-PCR, in situ hybridization, western blot, immunohistochemistry and flow cytometry analysis were used to research the expression pattern and function of SPATA12. The spatial and temporal expression of SPATA12 gene and protein showed that it were detected in adult testis and mature sperm, but the lack of expression was seen in normal fetal testis. The SPATA12 gene and protein were expressed in seminiferous tubules, more precisely in spermatocyte, spermatids and spermatozoa, no expression in sertoli cells and leydig cells. These observations demonstrated it would be germ cell-specific and developmental stage-specific and be involved in development of testicular maturation. It was found that the expression level of SPATA12 mRNA in male infertility testis was associated with the amounts and density of germ cells. With the decrease of germ cell, the expression of SPATA12 mRNA was weak or lack. In addition, SPATA12 expression down-regulated in the teratomas and MCF-7 cell line, and were absence in seminomas, Hela cell line, MGC cell line. The flow cytometry analysis of SPATA12 in human Hela cell line indicated that the expression of SPATA12 gene could delay the progression of G1-S in cell cycle, while it had no effect on the apoptosis of cells which suggested that the inhibitory effect of SPATA12 gene on cell proliferation. All the results indicated that SPATA12 might play an important role in spermatogenesis and controlling the carcinogenesis of testis.
KEY WORDS: testis, germ cell type-specific, stage-specific