Analysis of miR-29a and miR-34a Expression During Various Reproductive Stages in Iraqi Awassi Ewes and Their Correlation with Litter Size, Offspring Sex, and Blood Attributes

This study was investigated the correlation between miR-29a and miR-34a expression in Iraqi Awassi ewes during different reproductive stages and their potential as biomarkers for assessing pregnancy health, birth type, sex as well as blood parameters. Blood samples were obtained from five Iraqi Awassi ewes (3.5–4.5 years with 45–50 kg body weight), pre-mating (0), 14, and 45 day post-mating (PM), along with 75 and 135 days of pregnancy. miRNAs (miR-29a and miR-34a) were detected by using RT-qPCR. The relative expression of miR-29a was significantly increased (P ≤0.05) within different day as 45 (16.25 ±5.194), 75 (14.32 ±4.09), and 135 (13.29 ±6.52) of pregnancy compared to 0 and 14 day respectively. Additionally, a higher relative expression of miR-34a (P ≤0.05) was observed on day 135 of pregnancy (2.3 ±1.05) when compared to the other reproductive periods. Both miR-29a and miR-34a showed no differences in terms of birth type and sex. Regression coefficient analysis identified a significant relationship between miR-29a expression and various metabolic and biochemical parameters, such as serum amino acids, fatty acids, and estrogen levels. The analysis indicated that miR-29a exhibited an inverse correlation with amino acids while demonstrating a direct correlation with fatty acids and estrogen. In conclusion, miR-29a and miR-34a could serve as valuable biomarkers for monitoring the health of pregnancy in Awassi ewes. This study provides new insights into the function of miRNA in reproductive physiology, paving the way for improved management of sheep reproduction.