The effect of the LCORL gene on the body conformation of the Kazakh Mughaljar horse breed

Abstract

Background and Aim. Horse breeding in Kazakhstan is a traditional and important sector. However, during its development, several shortcomings and issues arise. For example, genetic selection is rarely applied in the process of breed improvement. Therefore, this study aimed to investigate the effect of the LCORL (ligand-dependent nuclear receptor corepressor-like) gene on the body conformation and performance traits of the offspring descended from the stallion lines “Zaman” and “Bakai” belonging to the Ertis factory type of the Mughalzhar horse breed. The goal is to use the genetic material for the selection of breeding stallions.

Materials and Methods. Wool samples were collected from 52 stallions aged between 15 and 18 months, descended from the stallion lines “Zaman” and “Bakai” of the Ertis factory type of the Mughalzhar horse breed, kept at the “Azamat 2” farm located in Abai region. DNA was extracted from the samples for genetic analysis, and an association study of the LCORL gene was conducted using the single nucleotide polymorphism (SNP) method. As a result of the study, gene polymorphisms associated with productive traits were identified.

Results. Based on the results of the single nucleotide polymorphism (SNP) analysis, we identified a heterozygous C>T mutation at position g.228 of the LCORL gene in the genome of the Mughalzhar horse breed, i.e., the SNP C>T. This SNP was classified into the following genotypes: CC, CT, and TT. Analysis of allele and genotype frequencies showed that the g.228 C>T SNP deviated from Hardy-Weinberg equilibrium (HWE) (p < 0.05). The polymorphism information content (PIC) indicated a moderate level of polymorphism (0.25 < PIC < 0.50). The CT genotype was more frequent than the CC and TT genotypes.Regarding the association between genotypes of the g.228 C>T SNP of the LCORL gene and body measurements of the Mughalzhar horse breed, the CT genotype showed a stronger correlation with traits such as wither height, body diagonal length, chest girth, cannon girth, and body weight compared to the CC and TT genotypes. Additionally, the TT genotype exhibited a stronger association with wither height, cannon girth, and body weight compared to the CC genotype.

Conclusion. Based on the results of the SNP analysis mentioned above, the LCORL gene may be used as a molecular marker to further improve the breeding qualities of the offspring descended from the stallion lines “Zaman” and “Bakai” of the Ertis factory type of the Kazakh Mughalzhar horse breed. However, the effect of this gene on the productive traits of horse breeds still requires additional research.