ALPHA-LACTALBUMIN GENE POLYMORPHISMS IN RELATION TO MILK PROTEIN CONCENTRATION IN MAGHRABI CAMEL

Alpha lactalbumin is one of the major proteins of camel milk whey and essential for the biosynthesis of lactose at the level of mammary glands. The objective of this study is identifying genetic polymorphism of the alpha-lactalbumin gene and its relation­ship with milk protein concentration of Maghrabi camel. Twenty one females of Maghrabi camel belonging to Camel Researche Station, Matrouh, Agricultural Research Center, Ministry of Agriculture and Land Reclamation, Egypt were used. Milk and blood samples were collected for the analysis of milk composition, protein electrophoresis and alpha-lactalbumin gene sequencing. Bioinformatics analysis was done to accomplish the PCR based sequencing technique to investigate the different Single Nucleotide Polymorphisms (SNPs) of alpha-lactalbumin gene. Results of camel milk composition percentages of protein, fat, lactose, total solids and solids not-fat were 3.2, 3.5, 4.8, 12.6 and 9.1, respectively. The alpha-lactalbumin protein band with molecular weight of 14.6 kDa was identified in different density concentrations. Alpha-lactalbumin gene amplified band with about 1000 bp length was detected in all studied samples. After PCR amplification, samples were divided into three groups according to milk protein concentration as follows, high (3.4-3.8%), medium (3.0-3.4%) and low (2.5-3.0%). The obtained sequences were submitted and accepted at the International Gene Bank and got the accession number KF648561.1. Several SNPs were found to be repeated in many camels in the nucleotide position and molecular weights. However, SNPs at positions 255(G-A, 0.279) and 263(C-T, 0.286) of transition types showed apparent association with high milk protein concentrations. The obtained results indicated that the identified SNPs in the alpha-lactalbumin gene affect the milk protein concentration and may be used in camel selection programs.