The Association of BMPR1B and PRL Polymorphisms with Egg Productivity and Quality Traits in Japanese Quails

Egg productivity and quality are essential quantitative traits controlled by many genes, including those encoding bone morphogenetic receptor 1B (BMPR1B) and prolactin (PRL). This study aimed to identify the polymorphisms of BMPR1B and PRL and their association with egg productivity and quality traits in Japanese quail. The phenotypes of 73 female quails raised under an individual cage system were investigated, and their blood samples were analyzed. The phenotypes investigated included egg production, body weight at 1 to 6 weeks, egg weight, egg index, eggshell weight, eggshell thickness, albumen index, yolk index, yolk score, yolk weight, albumen weight, yolk ratio, albumen ratio, and Haugh unit. The polymorphisms of BMPR1B in exon 9 and intron 10 were investigated using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, while a 24 bp indel of PRL located in promoter region was directly detected by examining the size of the PCR products (154/130 bp). The association between BMPR1B and PRL polymorphisms with egg productivity and quality traits was analyzed using an independent sample t-test. The result showed that the BMPR1B did not have polymorphisms. On the other hand, two genotypes, DD and ID, were found for the 24 bp indel of PRL. Moreover, the t-test analysis results indicated no association between the 24 bp indel of PRL and egg productivity and quality (P > 0.05). In conclusion, BMPR1B was monomorphic, and PRL polymorphisms did not affect the egg productivity and quality traits of Japanese quails.