SNP analysis reveals estrogen receptor 1 (<i>ESR1</i>) gene variants associated with laying traits in quails

In this study, the estrogen receptor 1 (<i>ESR1</i>) gene was studied as a candidate gene for laying traits of two quail populations (the yellow-feather quail and chestnut-feather quail). Five pairs of primers were designed to detect single-nucleotide polymorphisms (SNPs) of exon 1, 2, 4, 8 and intron 1 of the <i>ESR1</i> gene by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and sequencing methods. Only the products amplified from exon 8 displayed polymorphism. The results showed one novel variation: a variation in exon 8 of <i>ESR1</i> gene (g.91C > T, KC977991 and KC977992). It was associated with some laying traits in two quail populations including egg weight, the age of first egg and egg number at 20 weeks. And the CC genotype was associated with superior egg number at 20 weeks. Therefore, we speculated that the variation in exon 8 of <i>ESR1</i> gene may have an effect on laying traits in the abovementioned quail populations