MiRNA Expression Profile Changes In The Ovary Of Rabbits In Response To Heat Stress

Numerous studies have highlighted the role of mi RNA in the deformation and necrosis of cells of ovarian tissue caused by heat stress,which ultimately affects ovarian function.This study used ELISA,HE staining,TUNEL staining,and small RNA sequencing to investigate the effects of heat stress on ovarian tissue and its mi RNA expression profile using New Zealand rabbits as experimental animals,screening out heat stress-related candidate mi RNAs and possible signaling pathways.The results of this study provide a foundation for understanding the regulatory mechanisms of mi RNAs in the ovaries of rabbits under heat stress and also offer a new avenue for studying the impact of heat stress on reproductive organs and processes.The results of the study are as follows:1.After heat stress,the body weight,ovarian weight and relative ovarian weight of the female rabbits in the HS group were significantly decreased(P < 0.05),the rectal temperature was significantly increased(P < 0.01),and the feed intake was decreased,but the difference is not significant.2.The serum biochemical indicators of female rabbits were detected by ELISA,and the result showed that the serum levels of CAT,GSH-Px,IL-2 and IL-8 in female rabbits were significantly reduced after heat stress treatment(P < 0.05).3.HE staining was used to detect the ovarian tissue of female rabbits,and the results showed that the follicles in the ovarian tissue of the female rabbits were obviously abnormal after heat stress,especially the primordial follicles.Compared with the CON group,the gap between follicle cells and primary oocytes in the HS group was significantly increased and the incidence of vacuolization of follicles was significantly higher(P < 0.05).4.TUNEL staining was used to detect the ovarian tissue of female rabbits,and the results showed that the apoptosis rate in the ovarian tissues of female rabbits was significantly increased after heat stress treatment.The apoptosis rate of ovarian cells in CON group was 1.04%,while that in HS group was 2.47%,and the apoptosis rate of ovarian cells in HS group was significantly increased(P < 0.01).5.Heat-stressed ovarian tissues were detected by Small RNA-seq,and 23 differentially expressed mi RNAs were found,including 15 up-regulated mi RNAs and 8 down-regulated mi RNAs.At the same time,functional analysis of its predicted target genes revealed potential signaling pathways.6.11 differentially expressed mi RNAs were randomly selected and verified by RTq PCR,and the results of mi RNA analysis obtained from RT-q PCR and mi RNA-seq indicated a close resemblance with changes in expression profiles,therefore,highlighting the reliability of the sequencing results.Meanwhile,9 target genes from candidate mi RNAs were selected for RT-q PCR verification,and the results showed that these candidate mi RNAs have potential targeting relationships with target genes.In conclusion,heat stress reduced the growth performance of female rabbits and caused damage to their ovarian tissue,leading to changes in the expression profile of miRNAs.