MYOSTATIN (MSTN) AND GROWTH HORMONE (GH) GENES POLYMORPHISMS IN DIFFERENT BREEDS OF RABBITS AND THEIR RELATIONSHIP WITH PRODUCTIVITY TRAITS

Abstract

The article highlights the results of a study of the genetic structure of populations of three breeds of rabbits (New Zealand White, Chinchilla, Poltava Silver) by markers of economically useful traits. The main attention is focused on the analysis of polymorphisms of two candidate genes: myostatin (MSTN), which is a key regulator of muscle tissue development, and growth hormone (GH), which controls the somatotropic axis and metabolic processes. The aim of the work was to establish the features of the distribution of alleles and genotypes at these loci, as well as to assess the associative effect of the MSTN gene polymorphism on meat productivity indicators. Genotyping was performed for single nucleotide polymorphisms (SNP) c.34C>T in the MSTN gene and c.-78C>T in the GH gene. Allele and genotype frequencies were calculated, and the correspondence of their distribution to the Hardy-Weinberg genetic equilibrium was analyzed. For the MSTN gene (c.34C>T) in the New Zealand White rabbit population, which was in equilibrium, a statistically significant association with economically useful traits was established. A selective advantage of heterozygotes was revealed: individuals with the ST genotype outperformed homozygotes (SS and TT) in average daily gains and paired carcass weight. Analysis of the c.-78C>T polymorphism of the GH gene in the Chinchilla and Poltava Silver breeds also confirmed the state of genetic equilibrium. At the same time, a high level of actual heterozygosity (Ho) was recorded for both populations, which significantly exceeded the expected (He). This, together with negative values of the fixation index (Fis), indicates an excess of heterozygotes, which indicates high genetic diversity and potentially better adaptability of populations. The results obtained prove that the studied polymorphisms of the MSTN and GH genes are effective markers for use in breeding programs (MAS) to monitor the genetic structure and accelerate the selection of rabbits for meat qualities.