Mubritinib, an inhibitor of the EGFR family member ErbB2, blocks oocyte maturation in bovine

Mubritinib, an inhibitor of the EGFR family member ErbB2, blocks oocyte maturation in bovine. 2. Journées du GdR 3606 Repr

L’insuline stimule le développement in vitro du follicule ovin du stade préantral au stade antral

International audienc

Insulin promotes in vitro development of ovine preantral to antral follicles

International audienc

Impact of FSH on small growing follicles in vitro : Focus on the Estradiol (E2) and Anti Mullerian Hormone (AMH) balance

National audienc

Anti-Müllerian hormone as a predictive endocrine marker for embryo production in the goat

Recently, we demonstrated the relationship between anti-Müllerian hormone (AMH) circulating concentrations, ovarian follicles, and embryo production in cattle. However, they have not yet been established in a species with a seasonal breeding activity. Thus, goats were subjected to repeated in vivo embryo production during the breeding season, at the end of the breeding season, and at the end of the anestrus season. Embryo production after FSH treatment was highly repeatable for each goat. Plasma AMH concentrations, measured before the first FSH treatment, were highly correlated with the number of collected, transferable, and freezable embryos, resulting from the three sessions of embryo production. Plasma AMH concentrations transiently decreased after each exogenous FSH treatment, but they showed little change with season, and no relationship was observed between AMH and endogenous FSH concentrations during seasonal transitions. Follicles of 1–5 mm in diameter were the main target of the FSH treatment and were major contributors to circulating AMH concentrations. Granulosa cell AMH expression decreased as the follicle approached terminal development, while the expression of maturation markers (CYP19A1 and FSHR) increased. In conclusion, circulating AMH concentrations can be predictive of the capacity of a donor goat to produce high or low numbers of high-quality embryos. This prediction could be accurately made from a single blood measurement of AMH during either breeding or anestrus seasons. Variability in the number of gonadotropin-responsive follicles of 1–5 mm in diameter between individuals resulted in the differences in circulating AMH concentrations measured between individuals

Modulation of the effects of FSH on the expression of steroidogenic enzymes and oestradiol receptors in small growing follicles by the Leukemia Inhibiting Factor (LIF)

Remerciements : US1426 GeT-PlaGe Génome et Transcriptome - Plateforme Génomique, Castanet TolosanModulation of the effects of FSH on the expression of steroidogenic enzymes and oestradiol receptors in small growing follicles by the Leukemia Inhibiting Factor (LIF). 2. Journées du GdR 3606 Repr

Rôle du gène <em>BCAR4</em> dans la fertilité femelle : expression et approche fonctionnelle <em>in vivo</em> chez le lapin

National audienc

BMP15 regulates the inhibin/activin system independently of ovulation rate control in sheep

Polymorphisms in the gene encoding bone morphogenetic protein 15 (BMP15) have been associated with multiple ovulations in sheep. As BMP15 regulates inhibin expression in rodents, we assumed that the ovarian inhibin/activin system could mediate part of the effect of BMP15 mutations in the regulation of ovulation rate in sheep. To answer this question, we have studied the effects of two natural loss-of-function mutations of BMP15 on the expression of components of this system. The FecX(R) and the FecX(Gr) mutations, when present respectively in Rasa Aragonesa ewes at the heterozygous state and in Grivette ewes at the homozygous state, were associated with a two-fold increase in ovulation rate. There were only small differences between mutant and wild-type ewes for mRNA expression of INHA, INHBA, ACVR1B, ACVR2A, FST or TGFBR3 in granulosa cells, and Inhibin A or Activin A concentrations in follicular fluid. Moreover, the effects of mutations differed between breeds. In cultures of granulosa cells from wild-type ewes, BMP15, acting alone or in synergy with GDF9, stimulated INHA, INHBA and FST expression, but inhibited the expression of TGFBR3 Activin A did not affect INHBA expression, but inhibited also the expression of ACVR2A The complexity of the inhibin/activin system, including positive and antagonistic elements, and the differential regulation of these elements by BMP15 and activin can explain that the effects of BMP15 mutations differ when present in different genetic backgrounds. In conclusion, the ovarian inhibin/activin system is unlikely to participate in the increase of ovulation rate associated with BMP15 mutations in sheep

Functional investigation of the human oocyte-expressed gene bcar4 using domestic animal models and genome editing.

National audienceWe have previously characterized BCAR4 (Breast Cancer Anti-estrogen Resistant 4) as a gene preferentially expressed in human oocytes as compared to ovarian somatic cells or non-pathologic non-reproductive tissues. BCAR4 is conserved in primates and in various domestic species such as cow, pig, dog, horse or rabbit, but it is not found in the genome of rodents. This pattern coincides with a delayed major activation of the embryonic genome, i.e. after several cleavages. BCAR4 is also an oncogene overexpressed in a subset of breast tumors and other cancers. Altogether, the restricted expression, proliferative properties and phylogeny suggested that BCAR4 may be involved in early embryonic divisions.We have analyzed BCAR4 expression in the cow. While RNA is already transcribed in the oocyte of preovulatory follicles, protein synthesis is delayed until late maturation, peaks in early cleaving embryos, persists until the morula stage to become undetectable in blastocysts. Microinjecting BCAR4-targeting small-interfering RNA significantly decreased BCAR4 expression and compromised in vitro blastocyst development, demonstrating that BCAR4 is a maternal-effect gene.To investigate BCAR4 function in vivo, the rabbit model was chosen for genome editing. Rabbits carrying an altered BCAR4 gene were produced using a transcription activator-like effector nuclease (TALEN). Wild-type, heterozygous and homozygous carrier animals were born following the expected mendelian ratio. They were viable and appeared healthy, as expected for animals with an altered maternal effect-gene. Efficiency of the genetic alteration was evaluated by reverse-transcription coupled to PCR. It showed that BCAR4 RNA expression was abolished in follicles from homozygous carriers as compared to their heterozygous and wild-type littermates. These females will be phenotyped onto various reproductive parameters to assess the role of BCAR4 in fertility in vivo