Oviductal glycoprotein 1 (OVGP1), also called oviductin, is an oviduct-specific protein and is suggested to play a rolein fertilization. Traditionally, Ovgp1 has been shown to be exclusively expressed by the oviduct; however, recentstudies have demonstrated its expression in some cancers. This observation led us to hypothesize that Ovgp1 mighthave some extra-oviductal expression. In the current study, we evaluated the mRNA and protein expression of Ovgp1in normal reproductive tissues of male and female mice. For the first time, we demonstrate that beyond the oviduct,Ovgp1 mRNA is expressed in the testis, epididymis and ovary, but not in the uterus, cervix, vagina, breast, seminalvesicles and prostate gland. In the testis, Ovgp1 mRNA was localized in the cells at the base of seminiferous tubules(most likely, Sertoli cells), while the protein was detected in the round and elongating spermatids. In the epididymis,Ovgp1 transcripts were localized in epididymal epithelium of the caput but not the corpus and cauda; OVGP1 proteinwas, however, not detected in any of the segments but was present in the epididymal sperm. In the ovary, Ovgp1transcripts and protein were detected in the surface epithelium, granulosa cells of the preantral and the antral folliclesand corpus luteum. In both, the ovary and oviduct, the expression of Ovgp1 was found to be higher at estrus stage thanat diestrus stage. To the best of our knowledge, this is the first study demonstrating the extra-oviductal expression ofOvgp1. Our data suggests that, beyond fertilization, Ovgp1 might have specific roles in gonadal physiology.
Volume 44 | Issue 6
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