Genome-wide association analysis of neck ring traits in NongHua ma male ducks.

Male NongHua ma ducks have more colourful feathers than females, especially considering that the former have a distinctive neck ring that is different from that of females. This ring development might be influenced by sex selection, the environment, genetics and other elements.Genome-wide association analysis (GWAS) was used to locate candidate genes that affect the neck ring formation of male ducks to investigate the genetic basis of this phenomenon.In this study, the neck ring area and width of 180 male ducks were assessed at ages 80, 90, 100, 110 and 120 d. GWAS was used to identify associated genes. There were 0, 7, 14, 48 and 21 possible candidate genes annotated around the 0, 12, 25, 76 and 40 SNP loci n corresponding regions. A total of 13 candidate genes were identified around 21 SNP sites at the neck ring width of 120 d.These significant genes were annotated and GO and KEGG enrichment analyses were performed. All SNPs that exceeded the significance threshold were annotated and preliminarily screened as candidate genes affecting neck ring formation. From analysis of gene function and enriched KEGG pathways, genes such as THSD1, SLC6A4, DGAT2, PRKDC, B3GAT2, ROR1, GRK7, EXTL3, TXNDC12, COL4A2, PRKG1, ACTR3 , were considered important candidate marker sites related to the neck ring. This provided the reference starting point for the genetic mechanism underlying duck feather colour.