Abstract
Intramuscular fat (IMF) content critically determines chicken meat quality. Extracellular vesicles (EVs) are essential mediators of intercellular communication through bioactive molecule transfer. Although co-culture systems have demonstrated that intramuscular preadipocytes (IMPs) promote lipogenic differentiation of muscle satellite cells (MSCs), the involvement of EVs remained unclear. Here, we isolated IMP-derived exosomes and confirmed their ability to enhance lipid accumulation in MSCs. Through small RNA sequencing and functional validation, we identified miR-125b-5p as a key regulator that directly targets and suppresses NR5A2, a newly identified negative regulator of avian adipogenesis. Inhibition experiments confirmed the essential role of this axis, as miR-125b-5p inhibition attenuated exosomal pro-adipogenic effects. Collectively, we demonstrated that IMP-derived exosomes facilitate MSC lipogenic differentiation through miR-125b-5p delivery. Our findings provide the first evidence of exosome-mediated muscle-fat crosstalk in poultry, establishing the miR-125b-5p/NR5A2 axis as a potential target for IMF modulation.