MicroRNA as Biomarkers for Physiological and Stress Processing in the Livestock.

Several microRNAs (miRNAs) have been identified as potential biomarkers widely dispersed in animals since 1993, and they have become a significant molecular biology research area. Because of their ability to activate extracellular molecules, stabilise bodily tissues, control cell-to-cell signals, and be easily extracted, miRNAs are outstandingly nominated as biomarkers. However, there is growing interest in targeting miRNAs to monitor physiological reproductive performance, including reproductive system development, embryo development, fertilisation, endocrinology, and animal welfare in stressful conditions. Moreover, miRNAs play significant roles in gene expression regulation; single miRNAs may have overlapping roles, and on a broader scale, multiple mRNAs govern a single function. Also, miRNAs serve as an intermediary messenger between the environment and reproductive performance, making them a vital component of miRNAs as performance biomarkers under environmental conditions like heat stress. This makes describing a unique miRNA's consequences and functions exceptionally challenging, which may confound many researchers. Also, enhancing our comprehension of miRNAs in response to testicular heat stress could potentially aid in preventing and treating spermatogenesis disorders. Therefore, the present review highlights miRNA's regulatory mechanisms on reproductive performance under heat stress to employ these findings in improving reproduction physiology research.