bta-mir-22: bta-mir-22, a microRNA identified in bovine species, plays a role in various biological pathways, including the mitochondrial L-carnitine shuttle pathway and calcium signaling, with a significant impact on pathways related to proteolysis and apoptosis [PMC6182065]. It targets the glutathione reductase (GSR) gene and is involved in the actin cytoskeleton signaling pathway [PMC6182065]. This microRNA is also implicated in muscle tenderness regulation and shares targets with lethal (let-7) miRNA [PMC6182065]. It has been identified as a potential regulator of tenderness through RIF analysis and has been found to target transcripts involved in calcium transport such as CACNA1B and ATP2B2 [PMC6182065]. bta-mir-22 is associated with transcripts related to oxygen storage and transport in muscle fibers, such as myoglobin (MB), and also targets genes involved in proteolysis like calpastatin (CAST) and calpain family members CAPN1 and CAPN11 [PMC6182065]. Furthermore, bta-mir-22 has been differentially expressed in bovine macrophages responding to M. bovis infection, suggesting its role in immune response regulation [PMC4978967]. Its high similarity to human miRNAs suggests potential functional relevance across species [PMC4167851], particularly during the late follicular phase of the bovine estrous cycle [PMC4438052].