Selected abstracts of reports at the XX International Scientific Conference «Factors in Experimental Evolution of Organisms» (September 22–26, 2025, Kyiv, Ukraine)

The preservation and rational utilization of the sheep gene pool are highly urgent issues in the development of modern sheep breeding.Contemporary methods of selection and breeding enable the realization of genetic potential for increased productivity and farm animals` breeding value.The Ukrainian Carpathian Mountain sheep is a local breed from the Carpathian region of Ukraine.This breed is well-adapted to grazing in mountainous terrain.The myostatin (MSTN) gene is considered a promising marker for improving economically important traits in livestock, particularly those related to muscle tissue development.Myostatin is a well-established negative regulator of muscle growth and development in mammals, and genetic variations within the ovine MSTN gene are linked to differences in sheep musculature.In order to find potentially beneficial mutations we performed Sanger sequencing of 1093 bp nucleotide sequence of the 3` untranslated region (3UTR) of MSTN gene of the Ukrainian Carpathian Mountain sheep.Eight known single nucleotide polymorphisms (SNPs) were found to be monomorphic in the Ukrainian Carpathian Mountain breed in 3UTR.The following genotypes were identified: c.*707TT, c.*709AA, c.*874TT, c.*1098AA, c.*1232GG, c.*1267AA, c.*1316GG, c.*1489GG.Thus, it can be concluded that marker-associated selection involving SNPs of the 3UTR region of the MSTN gene is not suitable for the Ukrainian Carpathian Mountain sheep due to the confirmed monomorphism of the studied SNPs in this region.Also, to identify SNPs within this breed, a 1062 bp sequence of intron 1 of the ovine MSTN gene was sequenced using Sanger sequencing.Sequence analysis revealed nine SNPs (c.373+241T>C, c.373+243G>A, c.373+246T>C, c.373+249T>C, c.373+259G>T, c.373+283T>C, c.373+323C>T, c.373+563G>A, c.373+607G>A), which collectively contributed to the formation of six distinct haplotypes.All loci, with the exception of the c.373+283T>C polymorphism, were found to be in Hardy-Weinberg equilibrium.We successfully identified several SNPs that may be of critical importance for future studies.It also lays the foundation for subsequent association studies needed to assess the potential of these SNPs as genetic markers for economically important traits in Ukrainian Carpathian Mountain sheep breeding.