QPCTL Affects the Daily Weight Gain of the F2 Population and Regulates Myogenic Cell Proliferation and Differentiation in Chickens

Molecular breeding can accelerate the process of animal breeding and improve the breeding efficiency. To date, many Indel molecular markers have been identified in livestock and poultry, but how Indels affect economic traits is not well understood. For molecular breeding, it is crucial to reveal the mechanism of action of Indels and to provide more accurate information. The purpose of this study was to investigate how the 52/224-bp multiallelic Indels of the chicken promoter area affect the daily weight gain of chickens and the potential regulatory mechanism of the gene. The analysis was conducted by association analysis, qPCR, dual-fluorescence assay and Western blotting. The results showed that Indels in the promoter region were significantly associated with the daily weight gain in chickens and that expression showed a decreasing trend in embryonic breast muscle tissues. Furthermore, expression was significantly higher in breast muscle tissues of the AC genotype than in those of the AB and BB genotypes. Based on the transcriptional activity results, the pGL3-C vector produced more luciferase activity than pGL3-A and pGL3-B. In addition, overexpression of promoted chicken primary myoblast (CPM) proliferation and inhibited differentiation. The results of this study suggest that Indels in the promoter region of the gene may regulate the proliferation and differentiation of CPMs by affecting the expression of , which ultimately affects the growth rate of chickens. These Indels have important value for the molecular breeding of chickens, and can be used as a candidate gene to regulate and improve chicken growth and development.