Fig. 7

Effects of miR-338-3p on the number of follicles, the oocyte mitochondrial-membrane potential and the oestrous cycle. (A) The control group consisted of 2-month-old female mice receiving injections of EGFP-adeno-associated virus (AAV) into their ovarian bursae and the miR-338-3p-overexpression group consisted of mice receiving injections of miR-338-3p-AAV. After 35 days of injection, total RNA from mouse ovaries was extracted respectively from the control group and the miR-338-3p-overexpression group and real-time PCR was performed to analyse miR-338-3p expression. U6 RNA was detected as the internal reference. (B-D) At 35 days post-injection, mouse ovaries were obtained and HE staining was used to analyze the differences in the number of follicles at all levels between the control group (B) and the miR-338-3p overexpression group (C). (E) mouse oocytes were harvested and stained with the JC-1 dye to analyse the oocyte mitochondrial-membrane potential in the control group (a-c) and the miR-338-3p-overexpression group (d-f). The green mitochondria showed maximum fluorescence emission between 515 and 530 nm, and the red mitochondria had an emission peak of 585 nm. The JC-1 monomers (green fluorescence) indicate a low mitochondrial-membrane potential, whereas the JC-1 polymers (red fluorescence) indicate a high mitochondrial membrane potential. (F, G) At 35 days post-injection, vaginal smears were collected daily from the mice and stained with HE to monitor the oestrous cycle. The dynamic line charts of the mouse oestrous cycles covering 14 consecutive days in the control group (F) and the miR-338-3p-overexpression group (G) are shown