Sheep Anti-Mullerian Hormone

The aim of this work was to study the secretion of anti-Müllerian hormone (AMH) during ovarian development in sheep before and after birth. We used immunocytochemistry of avidinbiotin and a monoclonal antibody specific for ruminant AMH. Only granulosa cells have immunoreactivity:

This immunoreactivity was influenced by the age of the animal and by the degree of follicular development. In the fetus, no immunoreactivity was detected in somatic cells of ovigerous cords at 70 days post-coitum (p.c.) or in primordial and growing follicles at 100 and 120 days p.c. 'occasionally in a few cells belonging to the preantral follicles at 120 days p.c.

AMH was never detected in the primordial follicles in the ovaries of 144 days p.c., at birth, at 8, 97, 145 days after birth or in adult ovaries. A weak reaction, triggered in small growing follicles, increased with follicle size to become more intense in antral follicles.

Immunoreactivity was strongly positive in granulosa cells, particularly those lining the antral cavity and close to the oocyte, while there was little or no reactivity in peripheral cells close to the basement membrane. Follicles without AMH reactivity were found all the time and their number decreased with age.