Genotypic confirmation of non-broody behaviour of white leghorn by 24bp indel(s) polymorphism at the promoter region of prolactin gene

Abstract

Broodiness is a sex-linked observable trait in most of the domestic hens but in case of White Leghorn breed this trait was found to be seldom. Prolactin hormone plays a major role in broodiness or incubation behaviour in birds. The main aim of the present study was genotypic confirmation of non-broody behaviour of White Leghorn by identifying a 24bp insertion-deletion (indel)s at the promoter region of prolactin gene. A total of 200 birds of White Leghorn were randomly selected from All India Co-ordinated Research Project (AICRP) on Poultry Improvement, Mannuthy, Thrissur, Kerala. Blood samples were collected from the selected birds and isolation of genomic DNA was done. Polymerase chain reaction (PCR) assay was carried out to identify a 24bp indel(s). Based on the polymorphic patterns, birds were categorized to three different genotype groups namely, II, ID and DD. Association of non-broody behaviour and egg production with 24bp insertion polymorphism was analyzed in White Leghorn. Our findings support the view that loss of maternal incubation behaviour in the White Leghorn breed is the result of 24bp insertion polymorphism and intensive selection which improves the egg laying persistency.