title: A new rolling culture-based in vitro fertilization system capable of reducing polyspermy in porcine oocytes.
abstract: The high incidence of polyspermy is one of the major obstacles during in vitro fertilization (IVF) in pigs. To overcome this, we developed a novel IVF method, which involves constant rotation. Oocytes matured in vitro were mixed with spermatozoa (0.2 × 10(5) sperm/mL) in an IVF medium (200 μL) using a 200 μL PCR tube. This tube was then rotated at 1 rpm for 6 h at 38.5°C in a rotation mixer (experimental group). A second PCR tube was simultaneously cultured without rotation (control group). The rate of polyspermy was evaluated 12 h after insemination and was significantly (P < 0.05; 21.0% vs. 48.3%) lower in the experimental group than in the control group. Sperm penetration rate was similar in oocytes from the experimental and control groups (75.2% vs. 83.1%). However, monospermic fertilization rate of the oocytes was significantly (P < 0.05; 44.8% vs. 21.2%) higher in the experimental group than in the control group. Furthermore, the rate of blastocyst formation (30.1% vs. 20.8%) increased in the experimental group, as compared to the control group. This present system will contribute to increase the efficacy of blastocyst production through reduction of polyspermic penetration.
authors.affiliation: Laboratory of Animal Reproduction, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kitaji
authors.forename: Shoji
authors.initials: S
authors.lastname: Ookutsu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sato
authors.forename: Kazuchika
authors.initials: K
authors.lastname: Miyoshi
mesh_terms: D000818:Animals; D001755:Blastocyst; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro / Q000379:methods*; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods; D007315:Insemination, Artificial; D008297:Male; D009865:Oocytes; D012399:Rotation; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000502:physiology; D013552:Swine
keywords: in vitro fertilization; oocytes; pig; polyspermy; rolling culture