Detection of MspI polymorphism and the single nucleotide polymorphism (SNP) of GH gene in camel breeds reared in Egypt
Growth hormone (GH) is an anabolic hormone synthesized and secreted by the somatotroph cells of the anterior lobe of the pituitary gland in a circadian and pulsatile manner, the pattern of which plays an important role in postnatal longitudinal growth and development, tissue growth, lactation, reproduction as well as protein, lipid and carbohydrate metabolism. The aim of this study was to detect the genetic polymorphism of GH gene in five camel breeds reared in Egypt which are Sudany, Somali, Mowaled, Maghrabi and Falahy, using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) technique. Also, this work aimed to identify the single nucleotide polymorphism (SNP) between different genotypes detected in these camel breeds. The amplified fragment of camel GH at 613-bp was digested with the restriction enzyme MspI and the result reveals the presence of three different genotypes; CC, CT and TT in tested breeds. Significant differences were recorded in the genotype frequencies between these camel breeds. The result shows that the Maghrabi breed that is classified as a dual purpose camels had higher frequency for allele C (0.75) than those in the other tested four breeds. The sequence analysis declared the presence of a SNP (C264T) in the amplified fragment which is responsible for the elimination of the restriction site C^CGG and consequently the appearance of two different alleles C and T. The nucleotide sequences of camel GH alleles T and C were submitted to nucleotide sequences database NCBI/Bankit/GenBank and have accession numbers: KP143517 and KP143518, respectively. It is concluded that only one SNP C→T was detected in GH gene among the five tested camel breeds reared in Egypt and this nucleotide substitution can be used as a marker for the genetic biodiversity between these camel breeds. Also, due to the possible association between allele C and higher growth rate, we can used it in marker assisted selection (MAS) for camels in breeding program as a way for enhancement of growth trait in camel breeds reared in Egypt.
Key words: Camel breeds in Egypt, GH, PCR, RFLP, SNPs.