PCR-RFLP Study of Candidate Genes for Egg Production in Layer Chicken

Abstract

Polymorphic variants of few candidate genes have been reported to be associated with production traits in layers. The objective of the present study was to genotype the long term selected pure-line layer population for Growth Hormone Receptor (GHR), Insulin Like Growth Factor -1 (IGF-1) and Prolactin (PRL) hormone gene and to observe their association with layer traits. Layer traits were recorded on 1082 pullets up to the age of 40 weeks under standard management conditions. Genotyping study was performed on 90 randomly selected pullets with reported PCR-RFLP markers for GHR, IGF-1 and PRL genes. The studied population revealed polymorphic pattern for GHR, IGF-1 and monomorphic for PRL. The frequency of Hind III ++ and Pst I ++ genotypes were high in comparison to Hind III - - and Pst I + - genotypes for GHR and IGF-1 gene respectively. Genotype-trait association analysis revealed a trend of association with means of some traits; however, the associations were not significant. The allelic and genotypic frequency of PRL gene at both promoter sites was 1.00 which confirmed the loss of broodiness in studied population. Results of this study indicated that direction of selection has supported the favourable alleles of GHR and IGF-1 genes in the studied layer population The Chi-square (χ2) test for goodness of fit was used to find out difference among various genotypes.