Adeno-associated virus-miR-128-3p sponge regulates breast muscle growth and intramuscular fat content in chickens

Chicken meat is a major source of protein worldwide, and consumer demand for its consumption and quality is increasing. Although broilers grow rapidly to meet consumer demand, broilers have problems of low flavor substances and low intramuscular fat. Balancing the "quantity" and "quality" of chicken meat is the core of breeding. Among microRNAs, miR-128 can regulate myoblast proliferation and fat accumulation, it remains unclear whether miR-128 exerts the same function in vivo. Thus, this study constructed an adeno-associated virus (AAV)-mediated miR-128-3p sponge vector was constructed, and 20 chickens were equally assigned to a control group (injected with Cytomegalovirus (CMV) vector) and an experimental group (injected with AAV-miR-128-3p sponge vector). The results showed that the body weight, breast muscle weight, and breast muscle rate of the experimental group increased, the muscle fiber diameter enlarged, the mRNA expression of miR-128-3p in breast muscle decreased, and the lipid droplet area in breast and leg muscles as well as the crude fat content in breast muscle increased. In addition, lipidomic analysis revealed that the levels of 5 types of triglycerides (TG) in breast muscle was up-regulated. This study demonstrates that the AAV-miR-128-3p sponge vector can increase the growth rate and intramuscular fat (IMF) content of chickens, providing a targeted approach to improve poultry meat quality.