Mitogenome-wide association study on body measurement traits of Wenshang Barred chickens

Mitochondria are best known for synthesizing ATP through the tricarboxylic acid cycle and oxidative phosphorylation. The cytoplasmic mitochondrial DNA (mtDNA) is important for maintaining the function. This study was designed to reveal the effect of mtDNA on chicken body measurement traits (BMTs). A population of 605 Wenshang Barred chickens were recorded BMTs, including body slope length, keel length, chest width, etc. The single-nucleotide polymorphisms (SNPs) of their mitogenomes were detected by PCR amplification and DNA sequencing. Totally 69 mutations in mitogenome were discovered, including 18 in noncoding region and 51 in coding region. By multi-sequence alignment and haplotype construction, the chickens were clustered into eight haplotypes and further three haplogroups. The association between BMTs and mtDNA SNPs, haplotypes and haplogroups were analyzed in the linear model by ASReml, respectively. Among them, the SNP mt11086 T/C in ND3 was found to significantly affect chest dept (p < .05) and was highly conservative by phylogenetic conservation analyses, which reflected the genetic effect on body size and growth of chickens. No significant association between the mitochondrial haplotypes or haplogroups and BMTs was found. The polymorphic site reflecting body size could be put into chicken breeding programs as the genetic marker.