Abstract: The present study was undertaken to explore the correlation between GNAS gene expression, polymorphism and plumage color in Korean quail. Trizol method was used to extract total RNA from different wing tip tissues of maroon Korean quail embryos and white Korean quail embryos at different development stages, and RT-qPCR was used to detect the mRNA expression level of GNAS gene in wing tissues of Korean quail embryos at different development stages and different feather colors; The full CDS sequence of the GNAS gene was cloned and analyzed by bioinformatics; Genomic DNA was extracted from wing tip tissue of embryos, incubated for 10 days, and the specific sequence of the GNAS gene was amplified by PCR. Asymmetrical PCR-SSCP method combined with sequencing was used to determine the genotype to analyze the effect of different genotypes on the formation of plumage color in Korean quail. The results showed that the expression level of GNAS gene in maroon quail embryos was significantly higher (P<0.01) than that in white quail embryos at 8-14 days. The open reading frame of the CDS region of the GNAS gene is 1 140 bp in length, contains 14 exons, and encodes a stable hydrophilic protein containing 379 amino acids. Two SNP loci were detected in the Korean quail GNAS gene, namely g.119221T>A in exon 12 region and g.121181A>G in 3'UTR region. The frequency distribution of the three genotypes (AA, AB and BB) of maroon plumage Korean quail in g.121181A>G mutation site in 3'UTR region was significantly different from that of white plumage Korean quail (P<0.01). These results suggest that the expression level of GNAS gene in Korean quail tissue was related to the formation of plumage color. The g.121181A>G mutation on the 3'UTR of the GNAS gene had a significant correlation with the plumage color traits of Korean quail. GNAS can be used as a candidate gene for studying plumage color of Korean quail.

Key words: Korean quail, GNAS gene, plumage color, gene expression, gene mutation