(L5361) Associations of inhibin alpha beta B  (INHAB) gene  polymorphism with sperm quality in the population of  Russian Holstein bulls

Elena Nikitkina (Russian Research Institute of Farm Animal Genetics and Breeding — Branch of the L.K. Ernst Federal S)| Anna Krutikova (Russian Research Institute of Farm Animal Genetics and Breeding — Branch of the L.K. Ernst Federal S)| Artem Musidray (Russian Research Institute of Farm Animal Genetics and Breeding — Branch of the L.K. Ernst Federal S)

The formation and functioning of the animal reproductive system occurs as a result of the coordinated interaction of a wide range of genes. The hormone inhibin (INHA) is a marker of Sertoli cell function and exocrine testicular function (spermatogenesis state). The aim of the work was to search for associations of inhibin alpha  beta B  (INHAB) gene polymorphism with sperm quality in the population of Russian Holstein bulls. Sperm traits (doublet ejaculate volume, concentration, progressive motility and the total number of spermatozoa) were evaluated over three years of bull use and the highest rates for each trait were selected. 32 bulls had contrasting traits. DNA was isolated from semen samples. Samples were sequenced using the Applied Biosystems 3500 Genetic Analyzer using the BigDye® Terminator v3.1 Sequencing Standard Kit according to the protocol. Genotyping was then performed by PCR-RFLP. Data was analyzed using ANOVA. All pairwise multiple comparison between means were conducted by t-test. As a result only one nucleotide substitution A> G (rs43408735) was identified. The substitution is located in intron 1 and does not lead to a change in the amino acid composition of the protein; however, the proximity to the exon can affect the splicing processes. The frequency of the alleles in our studies was A - 0.55, G - 0.45, which differs from the population data in the ENSEMBL database, where the frequency of alleles was A - 0.31, G - 0.69. The frequency of occurrence of genotypes according to our data was AA - 0.35, AG - 0.40, GG - 0.25. Bulls with the genotype AA had a highest doublet ejaculate volume (21.00 ± 5.850 ml),  total number of spermatozoa (31.43 ± 10.393 mln) than bulls with the genotypes AG (16.08±8.450 ml and 24.35 ± 14.555 mln)  and GG (10.75±6.065 ml and 14.80 ± 10.613 mln) (P˂0.05).  No significant differences were found in the concentration of spermatozoa and motility. But bulls with the AA genotype had the greatest concentration and motility. The bulls with GG genotype had the poorest semen quality. The study of polymorphism in the genes that determine the formation and functioning of the reproductive system will help to understand the basics of these processes, as well as use them as molecular genetic markers for culling young bulls according to sperm quality. 

Support or Funding Information
This research was funded by Ministry of Science and Higher Education of the Russian Federation, project № 0445-2021-0011.