Study on the regulation of sulfated zona glycoproteins associated with the reduction of polyspermy during in vitro fertilization of porcine oocytes

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K07992
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Animal production science
• Research Institution: University of the Ryukyus
• Principal Investigator: TATEMOTO Hideki 琉球大学, 農学部, 教授 (70227114)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: ブタ体外受精 / 多精子受精 / 透明帯 / 糖タンパク質 / 硫酸化糖鎖 / arylsulfatase A / 脱硫酸化処理

Outline of Final Research Achievements

This study was conducted to elucidate the reduction of polyspermy during IVF without adverse effect on embryo developmental competence through the regulation of sulfated glycoprotein of porcine zona pellucida (ZP).
Treatment of oocytes with 5 mU/mL sulfatase for 10 min before the onset of insemination or 5 ng/ml ARSA blocking peptide during IVF effectively protected polyspermic fertilization under conditions that maintained the high sperm penetration rate and developmental potency. The number of sperm bound to ZP and the incidence of inducing acrosome reaction were significantly decreased by these treatments; however, it should be noted that the treatments had no effect against the time course of changes in ZP glycoproteins with egg activation.
These findings indicate the possibility of reduction of polyspermy during porcine IVF but not the decrease of development to blastocyst stage in keeping with a role for sulfated glycoprotein of ZP and ARSA of spermatozoa.

Free Research Field

家畜繁殖学

Academic Significance and Societal Importance of the Research Achievements

ブタ卵体外受精(IVF)時には他の家畜種に比べて多精子受精が高頻度に起こることが知られている。そこで，本研究では，透明帯構成糖タンパク質の硫酸化糖鎖に着目し，媒精前のブタ卵透明帯に脱硫酸化処理を行うことで，効果的に多精子受精を抑制する新しいIVF法の確立が可能か否かを検討した。
本研究結果から，精子arylsulfatase Aと透明帯の硫酸化糖鎖との結合を処理することで，透明帯への結合精子数と透明帯結合精子の先体反応誘起率を有意に減少させ，精子侵入や胚発生能に悪影響を及ぼさずに多精子受精を効果的に抑制できることが明らかになった。