Downregulation of OX1R promoted apoptosis in mouse primary GCs. (A) Following the transfection with siOX1R and NC for 48 h, apoptosis in GCs was determined using flow cytometry. (B) The percentage of apoptosis was analyzed separately for early (lower right quadrants), late (upper right quadrants), and total apoptosis. The results are presented as the means ± SEM of three independent experiments. Different superscripts represent the level of significance between NC and siOX1R (** p < 0.01, *** p < 0.001). OX1R, orexin receptor type 1; NC, negative control; GCs, granulosa cells; siOX1R, orexin receptor type 1 siRNA.