Search for associations of bull sperm quality with ESR1 gene polymorphism

Materials and methods. The semen of 53 bulls was collected at OJSC Nevskoe. A total of 110 bull semen samples were analyzed. Sperm quality was determined using Argus-CASA (ArgusSoft, Russia). Membrane integrity was determined by staining the samples with nigrosine-eosin dye (Diam, Russia) and a Motic BA 410 microscope. Spermatozoa respiration was determined using an Expert-001 instrument. The functional state of the energy system was assessed by the reaction of respiration to the addition of the uncoupler of respiration and phosphorylation, 2,4 dinitrophenol (2,4-DNF). DNA for genetic analysis was isolated from semen by the phenol-chloroform method. Sanger sequencing was performed on an Applied Biosystems 3500 Genetic Analyzer using commercial BigDye® Terminator v3.1 Sequencing Standard Kits (Applied Biosystems) according to the manufacturer's protocol.Results. Sperm quality were characterized by high individual variability. Thus, the volume of the ejaculate was from 2 to 15 ml, the concentration of spermatozoa was from 0.6 to 1.7 billion/ml, the total number of spermatozoa in the ejaculate was from 1.6 to 15 billion, and progressive motility was from 0 to 85%. Four SNPs were identified for the ESR1 gene. No significant associations of ESR1 gene polymorphism were found, except for a significant association of ESR1 665 G>C with spermatozoa concentration and the number of swollen acrosomes