Analysis by two-dimensional electrophoresis of proteins secreted by sheep ovarian follicles: effects of the FecB gene, follicle size and atresia.

Proteins secreted by sheep ovarian follicles at different stages of maturation (small healthy, large healthy or large atretic) and originating from ewes with different ovulation rates (homozygous carriers or noncarriers of the FecB gene) were analysed by two-dimensional electrophoresis (PAGE) followed by computerized image analysis. Follicles were incubated intact for 1 h to assess steroidogenesis, and then incubated for 24 h in the presence of [35S]methionine. Secreted proteins were then resolved by iso-electric focusing followed by migration on 10% acrylamide slab gels and fluorography.

Number of mature follicles ovulating after a challenge of human chorionic gonadotropin in different breeds of sheep at different physiological stages.

The ovulatory response of ewes from breeds that differ widely in prolificacy (Ile-de-France, ++ Booroola Merino, Romanov, F+ Booroola Merino and F+ Booroola Romanov with adult ovulation rates of about 1.5, 1.2, 3, 3 and 3.

[Comparison of plasma levels of the gonadotropic hormone FSH, during the first 3 months of life, in male lambs, carrying or not carrying the "F" gene of proliferation].

We have found evidence in the male lambs, Booroola x Mérinos d'Arles and Booroola x -Romanov, during the first three months of life, for the expression of the "F" prolificacy gene. More FSH at the peripheral plasma levels is observed in males carrying one copy of the "F" gene as compared to non carriers of the same crosses in the same environment. However the difference is of too small amplitude to be utilised to discriminate male lambs carrying the "F" gene.