Single Nucleotide Polymorphisms in the Promoter Region of MyoG Gene Affecting Growth Traits and Transcription Factor Binding Sites in Guizhou White Goat (Capra hircus)

<b>Objective</b>: Growth traits are important economic characteristics in livestock. Genetic polymorphism has great influences on the improvement of goat growth traits. As an important member of the myogenic regulatory factor (MRFs) family, <i>MyoG</i> gene polymorphisms can alter the growth characteristics in goats. In this study, we aimed to investigate the regulation mechanism of the <i>MyoG</i> gene promoter region from the perspective of single nucleotide polymorphisms (SNPs) and transcription factors. <b>Methods</b>: Genomic DNA sequencing was carried out to detect SNPs in the -1000 bp upstream to 300 bp downstream of the <i>MyoG</i> gene promoter region in 224 Guizhou White goats (<i>Capra hircus</i>), and the genetic parameters of novel SNPs were calculated. The association between SNPs and growth traits, comprising body weight, body length, body height, chest circumference and cannon circumference, were analyzed using one-way ANOVA by IBM SPSS 23.0 software according to the general linear model. Transcription factor binding sites in the promoter region of the <i>MyoG</i> gene before and after mutation were predicted using bioinformatics software programs. <b>Results</b>: Four SNPs, including g.-709C>T, g.-461G>T, g.-377G>T and g.-249G>A, were identified in the 1 246 bp promoter region of the <i>MyoG</i> gene in Guizhou White goats. Based on χ² test, the g.-709C>T and g.-461G>T loci were consistent with Hardy-Weinberg equilibrium, while two other SNPs were deviated from Hardy-Weinberg equilibrium in Guizhou White goats. Association analysis revealed that the body weight of those with the CT genotype at the g.-709C>T locus was greater than of those with the CC and TT genotypes in Guizhou White goats (<i>p</i> < 0.05). At the g.-461G>T locus, the body weight of individuals with the GG genotype was significantly higher than that of those with GT genotype (<i>p</i> < 0.01). The body length of individuals with the GG genotype formed by the g.-249G>A locus was significantly higher than that of those with the GA genotype (<i>p</i> < 0.01). Online software programs found that four SNPs within the promoter region of the <i>MyoG</i> gene changed some transcription factor binding sites. <b>Conclusions</b>: Mutations of the <i>MyoG</i> gene promoter region may have a significant regulatory effect on the growth traits of Guizhou White goats. The small sample size may be one of the limitations for this study; nevertheless, these findings could provide a theoretical basis for further exploring the relationship between the four SNPs studied and the growth traits in Guizhou White goats, as well as the promoter function of the <i>MyoG</i> gene.