Ovarian Expression of ADAMTS1 and PI3K/Akt Pathway Genes in Mongolian Sheep with Different Lambing Phenotypes

Background: ADAMTS1 participates in ovarian extracellular matrix remodeling and ovulation, but its association with reproductive performance in Mongolian sheep requires further investigation. This study compared ovarian ADAMTS1 and PI3K/Akt pathway-associated gene expression between ewes with documented singleton and twin lambing histories and examined responses of cultured granulosa cells (GCs) to LY294002. Methods: Twenty-four Mongolian ewes were selected, comprising 12 with singleton and 12 with twin births over at least two consecutive lambing seasons. Each category included six ewes in estrus and six in diestrus. Ovarian gene expression was assessed using reverse transcription quantitative real-time PCR (RT-qPCR). Cultured GCs were examined by immunofluorescence and treated with 15 μmol/L LY294002 or dimethyl sulfoxide (DMSO) as the vehicle control. Results: Ovarian ADAMTS1, PI3K, Akt, and PTEN mRNA levels were higher in both twin-history groups than in either singleton-history group (p < 0.05). Bcl-2 expression was highest in the twin-history estrus group, whereas BAX expression was higher in diestrus than in estrus in both lambing-history categories (p < 0.05). Following LY294002 treatment, growth-associated absorbance at 450 nm decreased, and ADAMTS1 and several pathway-associated transcripts were downregulated. BAX mRNA increased significantly in the twin-history groups (p < 0.05), but the increases in the singleton-history groups were not significant (p > 0.05). Conclusions: These findings indicate associations with documented lambing history and cellular responses to LY294002. They do not establish a direct regulatory relationship between ADAMTS1 and PI3K/Akt signaling or a causal role in twinning. Steroidogenic function, gonadotropin responsiveness, and apoptosis require direct functional validation.