The influence of SLCO2B1 gene polymorphisms on live weight in Manych Merino sheep

Abstract

The study aimed to evaluate the association of SLCO2B1 gene polymorphisms with live weight in Manych Merino rams. Genotyping was performed using whole-genome sequencing (NovaSeq 6000) of 30 clinically healthy nine-month-old rams, randomly selected from three unrelated lines (relatedness coefficient ≤0.5). Mapping to the ARS-UI_Ramb_v2.0 reference genome was performed in Ugene Unipro v.47.0. Polymorphisms in the SLCO2B1 gene (15: 53098859–53149487) and flanks (±500 bp) were filtered by depth ≥50× and genotype quality ≥30. Statistical analysis was performed after checking normality (Shapiro-Wilk) using Student's t-test. A total of 468 polymorphisms (424 SNPs) were identified. After filtering by frequency (≥13%) and checking association with live weight, 16 loci (all intronic) were selected. For SNP 53123291, carriers of the mutant allele exceeded the reference homozygotes by 23% (53.73±1.80 kg versus 43.69±1.56 kg; p<0.05). For SNP 53118588, the difference was +20.54% (57.57±2.54 kg versus 47.76±1.60 kg; p<0.05). The highest average live weight among all groups was recorded in carriers of the mutant allele 53118588 (57.57 kg). For SNP 53117725, reference homozygotes significantly exceeded carriers of the mutant allele by 14.78% (51.58±1.77 kg versus 43.95±1.44 kg; p<0.05). The frequency of the mutant allele for SNP 53123291 was 0.37, the proportion of individuals with the mutant allele was 63%. Thus, polymorphisms 53123291 and 53118588 are associated with significantly higher live weight, 53117725 – with lower. To understand the functional significance of the identified associations, further studies of the molecular mechanisms of the influence of these polymorphisms on economically useful phenotype traits are necessary.