A study of goat SRY protein expression suggests putative new roles for this gene in the developing testis of a species with long‐lasting SRY expression

Abstract

The testis-determining gene SRY is not well-conserved among mammals, and particularly between mouse and other mammals. To evaluate SRY function in a nonrodent species, we produced an antibody against goat SRY and used it to investigate the expression pattern of SRY throughout goat testicular development. By contrast with the mouse, SRY is primarily expressed in most cells of XY genital-ridges and not solely in pre-Sertoli cells. Between cord formation and prepuberty, SRY remains expressed in both Sertoli and germinal cells. During adulthood, SRY expression declines and then disappears from meiotic germ cells, only remaining present at low levels in some spermatogonia. Unlike the germinal lineage, SRY continues to be highly expressed in adult Sertoli cells with a typical nuclear staining. Our data indicate that in goat, the role of SRY may not be limited to testis determination and could have other functions in testicular maintenance and hence male fertility. Developmental Dynamics 239:3324-3335,

Expression profile of the SOX9 gene in the testes of sexually immature and mature male goats (Capra hircus), and its potential influence on postnatal testis development

“…The inter-individual differences were negligible in this group, indicating that the expression of the SOX9 gene was quite stable in sexually mature male goats, which is in accordance with the results of Montazer-Torbati et al (2010).…”

“…At this stage of testicular development, AMH is strongly inhibited by an increasing concentration of intra-testicular androgens acting via androgen receptors (Grinspon and Rey 2010). Sexually mature males from the control group (sexual maturity period) were characterised by the lowest testicular levels of SOX9 mRNA transcripts, as also previously reported by Montazer-Torbati et al (2010). However, whether this is a permanent decrease or only transcriptional silencing during the spring-summer season (when reduced sexual activity in seasonal breeds is observed) remains unclear.…”

“…As the amount of SRY transcripts is dramatically reduced at this stage (Montazer-Torbati et al 2010), this elevated expression of SOX9 would appear to be SRY-independent. Nevertheless, the extended regulatory element TESCO, as already mentioned, may be involved in maintaining an appropriate level of SOX9 transcripts.…”

“…Th erefore, other factors must be involved in maintaining SOX9 expression. A recent study by Montazer-Torbati et al (2010) directly challenges this model and shows that, in goats, SRY transcript levels, which peak at 36 days post-coitum (dpc), are maintained until about the fi rst month after birth before drastically decreasing in sexually mature individuals. Consequently, it can also activate SOX9 transcription in the fi rst weeks of postnatal life.…”

“…At 3-4 months of age, the developmental stage of the gonads of male goats is associated, fi rst and foremost, with the onset of intensive gonocyte divisions and their further differentiation into prespermatogonia. Th e high AMH levels (induced by SOX9) maintained at this time inhibit their entry into meiotic divisions, simultaneously inhibiting the proliferation of interstitial cells (Montazer-Torbati et al 2010). Immature sustentacular cells also proliferate, but the intensity of this process depends, among other things, on the reduction in endogenous oestrogens elicited by the irreversible transformation of androgens by a microsomal enzymatic complex named aromatase (Kao et al 2012).…”