Immunolocalization of anti-Mullerian hormone in bovine fetus ovary

The anti-Mullerian hormone (AMH) or Mullerian Inhibiting Substance (MIS), produced by the Sertoli cells induces the regression of Mullerian ducts in male embryos (Jost, 1953), however its receptors are present in both sexes (Rey et al, 2003). Granulosa cells from ovarian follicle are homologous to Sertoli cells and also produce AMH (Vigier et al, 1984). Munsterberg u0026 Lovell-Badge (1991) observed AMH restricted to granulosa cells on the sixth day after birth. In antral follicles only cells near to the oocyte and a few granulosa cells surrounding the antrum produced AMH (Lee et al, 1996). In humans, the AMH blocks meiosis in fetal ovary and it is observed in granulosa cells of preantral follicles on fetal ovaries only from the 36th week (Rajpert-De Meyts et al, 1999). In ovaries of ewes AMH was detected in granulosa cells pre and post birth (Bezard et al., 1987) and females without AMH show early follicular depletion (Durlinger et al, (1999). Since there are no published studies on AMH in bovine fetuses this work aimed to immunolocalize AMH in ovaries of bovine fetuses between 24-79cm CRL (4 to 7 months) collected from a slaughter cows. Ovaries were fixed in 10% of paraformaldehyde, processed for conventional histology, cut with a rotative microtome, deparaffinized, and subjected to immunohistochemistry protocol using the anti- AMH 1:50 (SC 28912, Santa Cruz Biotechnology) according to the manufactureru0027s instructions. There was light staining in granulosa cells but not in the theca cells. However, intense staining was observed in the cytoplasm of the oocyte of primordial follicles, primary, secondary and antral follicles, at all ages analyzed, suggesting that despite being produced by granulosa cells, AMH concentrates in the oocyte cytoplasm. According Modi et al (2006), differences in AMH expression patterns between species make the understanding of AMH role in ovarian physiology difficult and taking into account that there are no studies in the literature on the presence of AMH in fetal bovine ovaries more studies are necessary for better understanding of the role of this protein in ovarian development of fetuses.