Supplementation of equine early spring transitional follicles with luteinizing hormone stimulates follicle growth but does not restore steroidogenic activity

Schauer, Stephanie N.; Briant, Christine; Ottogalli, Monique; Decourt, Caroline; Handel, Ian; Donadeu, F.X.

doi:10.1016/j.theriogenology.2010.11.016

Cited by 4 publications

(1 citation statement)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our finding in experiment 1 of reduced mean levels of IGF1 in DA relative to DO follicles and a tendency for progesterone levels to be lower in DA follicles is in agreement with earlier reports on deficient steroidogenesis and IGF1 production by dominant follicles during the luteal phase in mares (Goudet et al 1999, Bridges et al 2002 and indicates the developmental deficiencies of DA follicles, presumably induced by reduced circulating LH levels (Schauer et al 2011). However, despite the differences in IGF1 and progesterone levels, follicular fluid levels of the miRNAs examined were not different between DO and DA follicles, suggesting that these miRNAs are not primarily involved in the LH-driven final maturation of dominant follicles.…”

Section: Mirnas In Equine Folliclessupporting

confidence: 93%

Involvement of miRNAs in equine follicle development

et al. 2013

View full text Add to dashboard Cite

Previous evidence from in vitro studies suggests specific roles for a subset of miRNAs, including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, and miR-212, in regulating ovarian follicle development. The objective of this study was to determine changes in the levels of these miRNAs in relation to follicle selection, maturation, and ovulation in the monovular equine ovary. In Experiment 1, follicular fluid was aspirated during ovulatory cycles from the dominant (DO) and largest subordinate (S) follicles of an ovulatory wave and the dominant (DA) follicle of a mid-cycle anovulatory wave (nZ6 mares). Follicular fluid levels of progesterone and estradiol were lower (P!0.01) in S follicles than in DO follicles, whereas mean levels of IGF1 were lower (P!0.01) in S and DA follicles than in DO follicles. Relative to DO and DA follicles, S follicles had higher (P%0.01) follicular fluid levels of miR-145 and miR-378. In Experiment 2, follicular fluid and granulosa cells were aspirated from dominant follicles before (DO) and 24 h after (L) administration of an ovulatory dose of hCG (nZ5 mares/group). Relative to DO follicles, L follicles had higher follicular fluid levels of progesterone (PZ0.05) and lower granulosa cell levels of CYP19A1 and LHCGR (P!0.005). Levels of miR-21, miR-132, miR-212, and miR-224 were increased (P!0.05) in L follicles; this was associated with reduced expression of the putative miRNA targets, PTEN, RASA1, and SMAD4. These novel results may indicate a physiological involvement of miR-21, miR-145, miR-224, miR-378, miR-132, and miR-212 in the regulation of cell survival, steroidogenesis, and differentiation during follicle selection and ovulation in the monovular ovary.

show abstract

Section: Mirnas In Equine Folliclessupporting

confidence: 93%