Association of prolactin gene with laying traits in Merawang and KUB-2 chicken

Prolactin gene (PRL) is one of the physiological candidate genes for egg production which can be used as a marker-assisted selection. It was a peptide hormone that has a wide spectrum of regulated functions. In chicken, PRL leads to in reproductive cycle such as brooding behavior which causes a decrease in egg-laying intensity. The study aims to identify Single Nucleotide Polymorphism (SNP) in exons 2 and 5 of the PRL gene and its association with egg production, and (age, body weight, egg weight) at the first egg in Merawang and KUB-2 chicken. A total of 40 Merawang and KUB-2 chickens were used in the study. SNPs in exon 2 and 5 of the PRL gene were identified with direct sequencing and analysis using Bioedit. The association of genotype with laying traits was analyzed using the Generalized Linear Model (GLM) procedure of SAS. The result found 2 and 4 SNPs at exon 2 and 5 of the PRL gene in Merawang and KUB-2 chicken. Based on the chicken breed there are found the same SNP at Merawang and KUB-2 chicken, were 1) g.3805C>G and g.3838C>T at exon 2 and 2) g.7927C>G, g.7955C>G, g.8030A>T, and g.8052T>C at exon 5. In exon 2 the mutation site at SNP g.3838C>T, while in exon 5 at SNP g.8052 T>C were polymorphic. The SNP g.3838C>T at exon-2 and g.8052 T>C at exon-5 were significantly (P<0,05) associated with egg production, age at first egg, and body weight at first egg.