Growth hormone gene polymorphism in Chinchilla and Poltava silver rabbit populations

Goal. To study the genetic structure of the rabbit population based on the polymorphism of the growth hormone (GH) gene locus, and to determine allelic and genotypic variants based on the marker mutation c.78C>T. Methods. The study was conducted on Chinchilla and Poltava silver rabbit populations. Genotyping was performed by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and subsequent restriction analysis. DNA was isolated from individual whole blood samples. Amplification was performed in a MiniAmp programmable thermal cycler (Thermo Fisher Scientific) using specific primers. Amplification products were treated with BstUI restriction endonuclease. Restriction fragments were separated in a 2.0% agarose gel with the addition of ethidium bromide. Based on the obtained data, the actual (O) and theoretical distribution of genotypes (E), genotype and allele frequencies, actual (Ho), and expected (He) heterozygosity were calculated in accordance with generally accepted methods. Statistical data processing was performed using GENALEX 6.5 software and Microsoft Excel 2019. Results. A BstUI-polymorphism was detected at position -78 of the start codon of exon I (c.C>T). In the studied rabbit breeds, the heterozygous genotype ST prevailed with a frequency of 0.570 in Chinchilla and 0.605 in Poltava silver. The homozygous genotype TT occurred least often — with a frequency of 0.17 and 0.18, respectively. The frequency of the C allele was 0.60, and the T allele — 0.51 in the population of Chinchilla rabbits; in Poltava silver, the frequencies of these alleles were at levels of 0.51 and 0.48, respectively. The results of the study showed that both experimental populations by the GH locus were in the state of genetic equilibrium according to Hardy-Weinberg, which indicated the absence of microevolutionary changes in the process of their reproduction. Conclusions. The features of the distribution of individuals according to different genotypes of the GH gene in rabbit populations of both breeds, revealed in this study, justified the need for further studies to establish an associative relationship between allelic variants of the growth hormone gene and quantitative and qualitative indicators of productivity of this type of farm animals.