The genetic basis of the sperm quality of stallions

Abstract

One of the important factors affecting the reproductive function is the genotype of the animal. The method of genomic selection is based on the use of polymorphic single nucleotide substitutions (SNP) as markers for determining the value of the genotype of an animal or plant. The formation and functioning of the reproductive system of animals occurs as a result of the coordinated interaction of a wide range of genes. The search for genomic associations of GWAS (Genome-Wide Association Studies) with signs of fertility will allow further selection of animals based on these indicators at the genomic level. Sperm was obtained with the help of mares in hunting and on a phantom using an artificial Hannover vagina (Minitube, Germany). The sperm of each stallion was collected at least three times. The semen quality of 96 stallions of different breeds (Arabian, Akhal-Teke, Trakenen, thoroughbred horse, Oryol trotter, French trotter, Soviet heavy horse, Shetland pony, Welsh pony, horses of different breeds) was analyzed. High variability of sperm quality indicators was revealed. For example, the concentration of sperm in the ejaculate varied from 59 to 514 million /ml, progressive mobility from 20 to 87%, and the number of cells without damage from 21.6 to 95.6%. Such variability of the studied features makes it possible to assume that their formation in the process of ontogenesis occurs under the influence of genetic factors. The GWAS analysis of ejaculate volume, concentration and motility of stallion sperm revealed potential candidate genes associated with these indicators. The associations identified in our study are promising candidates for further identification of the biological mechanisms underlying the quality of stallion sperm.