Identification of miRNA-mRNA Regulatory Networks Reveals Potential Key miRNAs in Goat Intramuscular and Subcutaneous Adipose Formation.

The differential fat deposition in intramuscular (IMF) and subcutaneous (SCF) adipose tissues significantly influences goat meat quality. While microRNAs (miRNAs) are key post-transcriptional regulators, the shared key miRNAs governing adipogenesis across different adipose depots remain largely unexplored in goats. In this study, intramuscular and subcutaneous preadipocytes were isolated from the same healthy 7-day-old male Jianzhou Da'er goat, and each experimental group comprised five independently cultured cell replicates derived from this donor. Integrated miRNA and mRNA sequencing was performed on undifferentiated intramuscular (JNE) and subcutaneous (PE) preadipocytes and their corresponding adipocytes after 72 h of differentiation (JNC and PC, respectively), allowing the identification of depot-specific and shared differentially expressed miRNAs (DEmiRNAs) and mRNAs (DEmRNAs). By constructing miRNA-mRNA regulatory networks, chi-miR-1 was identified as the highest-degree miRNA node in the shared network and was therefore prioritized for functional evaluation. RT-qPCR, chi-miR-1 mimic and inhibitor transfection, Oil Red O staining, and BODIPY staining showed that chi-miR-1 overexpression increased lipid droplet accumulation, whereas its inhibition produced the opposite effect in both intramuscular and subcutaneous adipocytes. Furthermore, bioinformatic target prediction and network analysis identified chi-miR-1-PPARG and chi-miR-206-IGFBP3 as predicted potential regulatory relationships; these interactions were not directly validated experimentally. Our findings, obtained using cells derived from a single donor, suggest that chi-miR-1 may serve as a candidate shared pro-adipogenic regulator under the present in vitro conditions and provide insights into miRNA-mediated regulation of adipogenesis in different goat adipose depots.