Sequence Analysis of Coding Region of Prolactin Gene in Milking Beetal Goats

Prolactin gene, Beetal goat, mammary gland, Sanger method, BioEdit, Single nucleotide polymorphismProlactin gene is involved in mammary gland development and milk production.This gene is not characterized molecularly in Pakistani goat breed.It was thus aimed to characterize genetic variations in prolactin gene in beetal goat, one of the famous breeds.A total of 20 goats at milking stage with 3-5 years' age were selected.DNA was extracted by salting-out method and amplification of exon 2, 3 and 4 of prolactin gene was done using specific primers.Amplified products were bidirectionally sequenced through Sanger method.BioEdit was used to edit and align sequenced data for detection of single nucleotide polymorphism while Codon Code aligner and MEGA6 softwares were used for molecular analysis and aligned sequence analysis respectively.Exon 2 and 4 were monomorphic with respect to reference sequence but a deletion of a single nucleotide was found in exon 3.This deletion at EX3174delA in coding region of Exon 3 resulted in change in the sequence of amino acids and converted Met to stop codon.This may alter protein structure, expression of the gene and may affect protein's stability.This premature creation of stop codon may lead to truncated protein, low yield of milk or reduction in nutritional value of milk.