Genetic variation of prolactin gene in Uttara fowl of Kumaon region and its association with growth traits

Prolactin hormone plays an important role in crop sac development, incubation, brooding and immune response of the bird. In the present study, an attempt was made to explore the genetic variation of prolactin gene in Uttara fowl, the local hill fowl of Kumaon region and white leghorn (WLH) birds and its association with their body weights at different ages. The fragments 130/154bp and 439bp of chicken prolactin gene promoter region were amplified using 24BP and 5FA primers, respectively in 100 Uttara fowl and 60 WLH birds. Amplified products were directly observed on 2.5% agarose gel for the presence or absence of 24BP indel. On the basis of primer 24BP in Uttara fowl two genotypes (ID and DD) were identified with frequencies 0.75 and 0.25 and frequency of I and D alleles were 0.38 and 0.62, respectively. However, in WLH birds two homozygotes II and DD were identified with the frequencies 0.67 and 0.33 and the frequency of I and D alleles were 0.60 and 0.40, respectively. Amplified product of 439bp fragment upon restriction digestion with AluI gave two genotypic patterns (CC and CT) in both Uttara fowl and WLH birds. In Uttara fowl the frequencies of CC and CT genotypes were 0.38 and 0.62, respectively with gene frequencies 0.69 and 0.31 for C and T allele, respectively. In WLH, the frequencies of CC and CT genotypes were 0.65 and 0.35, respectively with gene frequencies 0.82 and 0.18 for C and T allele. Prolactin genotypes had significant (P<0.05) association with 8^th week body weight in Uttara fowl.