CAST/MspI gene polymorphism and its impact on growth traits of Soviet Merinoand Salsk sheep breeds in the South European part of Russia

Abstract

The purpose of this work was to study MspI polymorphism in the CAST gene in Soviet Merino and Salsk sheep breeds in the South European part of Russia and to find its relation with growth traits. Soviet Merino sheep have been found to have the M and N alleles with a frequency of 0.88 and 0.12 and the MM, MN, and NN genotypes with a frequency of 0.82, 0.12, and 0.06, respectively. Salsk sheep have been established to have the M and N alleles with a frequency of 0.89 and 0.11 and two genotypes, MM and MN, with a frequency of 0.78 and 0.22, respectively. A significant relationship between the CAST genotypes and the growth traits of Salsk sheep has been revealed. The absence of the homozygous NN genotype in Soviet Merino sheep did not allow us to determine what exactly causes the effect of increasing the average daily gain of sheep - the presence of the N allelic variant or the combination of the heterozygous M and N alleles. The results obtained show the CAST/MspI gene to be promising as a marker of sheep production in developing sheep breeding programs to improve fattening and meat qualities.