Nucleotide sequencing and DNA polymorphism studies of beta-lactoglobulin gene in native Saudi goat breeds in relation to milk yield

β-Lactoglobulin (β-LG) is the dominant non-casein whey protein found in milk of bovine and of most ruminants. The amino acid sequence of β-LG along with its 3-dimensional structure illustrates linkage with the lipocalin superfamily. Preliminary studies in goats indicated that milk yield can be influenced by poly - morphism in genes coding for whey proteins. The aim of this study is to identify and evaluate the incidence of functional polymorphisms in the exonic and intronic portions of β- LG gene in native Saudi goat breeds (Ardi, Habsi and Harri). Blood samples were collected from 300 animals (100 for each breed) and genomic DNA was extracted using QIAamp DNA extraction kit. A fragment of the β- LG gene from exon 7 to 3' flanking region