Association of vasoactive intestinal peptide receptor 1 gene polymorphism with layer economic traits in Rhode Island Red chicken

The research work was conducted to determine allelic polymorphism of vasoactive intestinal peptide receptor-1 (VIPR-1) gene and its association with layer traits in Rhode Island Red (RIR) chicken. Blood samples were collected from pullets (n=111) belonging to five hatches. Data on body weight at 20 weeks of age (BW20) and layer economic traits, viz. age at sexual maturity (ASM), egg weight at 28 (EW28) and 40 weeks (EW40) of age, and egg production up to 40 weeks of age (EP40)) were recorded. Genomic DNA was isolated by phenol chloroform extraction method. Samples were amplified for product sizes of 364, 434 and 486 bp of VIPR-1 gene. Amplified regions were digested by TaiI, HhaI and TaqI restriction enzymes. Digested fragments of TaiI and HhaI revealed monomorphism, whereas TaqI showed polymorphism. Allelic frequencies for polymorphic locus were 0.98 (A) and 0.02 (B) and genotypic frequencies for AA and AB were 0.96 and 0.04, respectively. The BW20 and layer traits (ASM, EW28, EW40 and EP40) were analysed by least-squares analysis of variance taking sire as random and hatch as fixed effect. Average ASM and egg production up to 40 weeks of age were 135.19 & PLUSMN;1.15 days and 124.55 & PLUSMN;1.94 eggs, respectively. Leastsquare analysis of variance had revealed significant effect of hatch on ASM, EW28 and EP40. However, effect of TaqI-RFLP genotypes was non-significant on layer traits. Further investigations on a larger sample basis are suggested to confirm effect of this mutation on layer traits as molecular marker in RIR chicken.