No abstract

Anti Müllerian Hormone, AMH, is believed to be the main agent in the freemartin syndrome. Supposing an active role of freemartin gonads in AMH secretion, in the present study, we aimed at investigating the presence and the localization of AMH producing cells either in fetal or in adult freemartin gonads. Our finding of positive AMH cells in a 26-week-old freemartin fetus indicates an active role of masculinized freemartin gonads in AMH secretion. However, the positive reaction, limited to few cells grouped in 'nests' in proximity to testis cord-like structures, supports a chimeric origin of such cells, migrated from the male co-twin. No adult freemartin, irrespective from the degree of masculinization, showed any AMH positive cell.

-The meiotic competence of canine oocytes collected from anoestrous bitch ovaries and cultured for 72 h in different media was studied. The base culture medium was TCM 199 enriched with 10% fetal bovine serum (TCM); the effect of supplementation with EGF (50 ng·mL -1 ) or ITS (insulin: 10 µg·mL -1 ; transferrin: 5.5 µg·mL -1 ; selenium: 5 µg·mL -1 ) was also studied. TCM was also compared to a Synthetic Oviductal Fluid (SOF). All the media contained FSH (0.1 UI·mL -1 ), LH (10 UI·mL -1 ), 17β-oestradiol (4 µg·mL -1 ) and kanamycin. Despite the anoestrous stage of the donor bitches, resumption of meiosis occurred in a high proportion of the oocytes, (mean value 77.3%). The number of oocytes showing the 'germinal vesicle breakdown' nuclear stage was not influenced by the type of the culture medium used. ITS had a positive effect on nuclear progression to later stages (from metaphase I to metaphase II); however, this effect was not statistically significant. bitch / anoestrous / oocytes / maturation / in vitro