Poster Presentation IXth International Conference on Boar Semen Preservation 2019

Application of Annexin V magnetic beads enriches boar sperm of high quality (#4.3)

Hsiu-Lien Lin 1 , Yu-Hsin Chen 1 , Lih-Ren Chen 1
  1. Physiology Division, Livestock Research Institute, Hsinhua, TAINAN, Taiwan

Cell injury results in a collapse of phospholipid asymmetry with externalization of phosphatidylserine (PS), which has a high affinity to Annexin V. Therefore, Annexin V could be a bait to attract damaged sperm. The purpose of this study was to utilize magnetic beads labelled with Annexin V to elute abnormal sperm from boar ejaculates, and also to compare different bead-sperm binding times in order to obtain the most optimal procedures for enrichment of intact boar sperm. Three Duroc-Meishan crossbred boars of 20-23 months of age were used in this study. Boar semen was collected and immediately transported to the laboratory. Sperm concentration was determined by a photometer (ACCUREAD, IMV, L’Aigle, France) and diluted to 300 × 106 cells/ml with PBS (Lonza, Basel, Switzerland). Nitrilotriacetic acid (NTA) magnetic beads (TOOLS, New Taipei, Taiwan) were incubated with Annexin V to produce Annexin V NTA magnetic beads. Each 300 × 106 sperm was treated with 400 µg Annexin V magnetic beads in a clean Eppendorf tube at room temperature for 20, 40 and 60 min, respectively. After bead-sperm binding treatment, the tube was placed on the magnetic stand for 30 sec to immobilize the beads at the tube wall, and supernatant was collected to evaluate sperm motility parameters by computer-assisted sperm analysis (CASA). The percentage of motile sperm after Annexin V NTA magnetic bead treatments of 20 and 40 min was increased by 19.9% and 5.6%, respectively (P < 0.01). The percentage of progressive sperm was also enhanced by 7.5%, 19.4% and 12.4%, respectively, after treatments of 20, 40 and 60 min (P < 0.01). Bead-sperm binding time of 20 and 40 min resulted in the most significant improvement of the percentage of motile and progressive sperm, respectively. According to our findings, we can conclude that Annexin V NTA magnetic beads may be an applicable method to treat boar semen in order to enhance sperm quality. However, additional experiments need to be performed for improving the efficiency. For example, the procedures should be adjusted to process more sperm numbers and also to reduce the cost in order to make this technique more practical. Furthermore, the fertility of boar sperm treated with Annexin V NTA magnetic beads has yet to be determined.