Sexually Dimorphic Expression of the Novel Germ Cell Antigen TEX101 During Mouse Gonad Development

Abstract

Prospermatogonia, or gonocytes, are the cells that differentiate from primordial germ cells to the first mature type of spermatogonia in the developing testis. Although prospermatogonia play a central role in this stage (i.e., prespermatogenesis), the details regarding their characterization have not been fully elucidated. Recently, we identified a novel mouse testicular germ cell-specific antigen, TES101 reactive protein (TES101RP), in the adult mouse testis. The protein TES101RP is also designated as protein TEX101. In the present study, we investigated the expression of TEX101 on germ cells in developing mouse gonads using histochemical techniques (i.e., immunohistochemistry, BrdU labeling, and TUNEL staining) and reverse transcription-polymerase chain reaction. TEX101 appeared on germ cells in both male and female gonads after the pregonadal period. In the testis, TEX101 was expressed constitutively on surviving prospermatogonia during prespermatogenesis. After the initiation of spermatogenesis, the prospermatogonia differentiated into spermatogonia. TEX101 expression disappeared from the spermatogonia, but reappeared on spermatocytes and spermatids. In the ovary, TEX101 was expressed on germ cells until the start of folliculogenesis; TEX101 was not detected on oocytes that were surrounded by follicular cells. These findings indicate that TEX101 is a specific marker for both male and female germ cells during gonadal development. Because the on and off switching of TEX101 expression in germ cells almost parallels the kinetics of gametogenesis, TEX101 may play an important physiological role in germ cell development.

Verification of Male Infertility Biomarkers in Seminal Plasma by Multiplex Selected Reaction Monitoring Assay

“…For quantitative data, see also Table II. the most promising candidates. TEX101 is a very specific marker for both male and female germ cells during gonadal development (28). TEX101 is a membrane glycoprotein expressed on the cell surface of germ cells during spermatogenesis but shed to the seminal plasma at the late stages of post-testicular sperm maturation (29).…”

Meisetz, A Novel Histone Tri-Methyltransferase, Regulates Meiosis-Specific Epigenesis

“…By the screening, we identified many meiosisor germ cell-specific genes, including Stra8, 26 Rec8, 27 Tex12 28 and Tex101. 29,30 Of the isolated genes, we focused on a gene encoding a protein that had a PR domain, a derivative of SET domain which has been known to act as catalytic domain for histone lysine methylation. 31 PR-domains bear 20-30% sequence identity with SET domain, and have catalytic activity for histone methylation similar to SET domain-containing proteins.…”

Distribution of Molecular Epitope for Ts4, an Anti-Sperm Auto-Monoclonal Antibody in the Fertilization Process

“…In contrast, during spermatogenesis, TEX101 first appears on the plasma membranes of prospermatogonia within the immature seminiferous cords of the fetal testis [6]. Although it is not expressed on spermatogonia, TEX101 reappears on meiotic cells including spermatocytes, spermatids, and testicular sperm following puberty [6]. Finally, TEX101 is shed from the cell surface of epididymal sperm during transport through the caput epididymis [7].…”

“…TEX101, a highly N-glycosylated glycosylphosphatidylinositol (GPI)-anchored glycoprotein [5], was originally identified as a protein containing the antigen epitope for a specific mAb, called TES101, produced by immunizing female mice with an allogenic testicular homogenate [4]. Previous studies by our research group have demonstrated that TEX101 is a unique germ cell marker that is expressed during gametogenesis [4][5][6][7][8][9] and shows sexually dimorphic expression in developing gonadal tissues. In the ovary, oogonia temporarily express TEX101 during the fetal period [6], but the molecule is not detected in the sexually mature ovary [4].…”