| Project/Area Number |
17580247
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Applied animal science
|
|---|
| Research Institution | University of the Ryukyus |
|---|
Principal Investigator |
TATEMOTO Hideki University of the Ryukyus, Faculty of Agriculture, Associate Professor (70227114)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAKADA Tadashi University of the Ryukyus, Faculty of Agriculture, Professor (70045136)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥300,000)
Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Keywords | hyaluronidase / polyspermy / in vitro fertilization / acrosome reaction / carbohydrate residues / porcine oocytes / boar spermatozoa / zona pellucida / 糖タンパク質 / 成熟 / 精子侵入 / tunicamycin / レクチン / 硬化 / ヒアルロニダーゼ活性 / タンニン関連化合物 / タンニン酸 / エラグ酸 / 没食子酸 / 多精子受精 |
|---|
| Research Abstract |
The abnormally high incidence of polyspermy after IVF is a major problem and often exceeds 50%; hence, the present study was conducted to examine the effects of tannin relatives on antihyaluronidase, in vitro fertilization (IVF) parameters, and the acrosome reaction (AR) induced by sperm-zona interaction. Among the tannin relatives, tannic acid and ellagic acid showed the strongest potency for blocking the hyaluronidase activity of boar sperm, with concentration-dependent inhibition over the range of 2-10μg/ml. When cumulus-free oocytes were inseminated in IVF medium containing 5μg/ml of the tannin relatives, polyspermy was significantly reduced by tannic acid and ellagic acid (32% and 29%, respectively) compared with oocytes treated without tannin relatives (69%) under conditions that maintained a high sperm penetration rate (P<0.05). Interestingly, the incidence of acrosome reaction induced by sperm-zona interaction was significantly decreased by the strong antihyaluronidase actions of tannic acid and ellagic acid compared with that in the absence of these compounds. Treatment with the compounds caused neither a protective proteolytic modification of the zona pellucida matrix before fertilization nor a reduction in acrosomal proteolytic activity or the number of zona-bound sperm. However, the modifications of GaINAc and GIcNAc residues throughout zona pellucida, responsible for the primary sperm-zona binding related to carbohydrate-mediated events, were required more than 4 and 18 h after artificial activation, respectively. It is thus suggested that the slower modifications of carbohydrate residues may reflect the remarkable increase in polyspermy during in vitro fertilization. These findings suggest that the antihyaluronidase action of tannic acid and ellagic acid effectively prevents polyspermy by suppression of acrosome reaction functionality induced by sperm-zona interaction and that hyaluronidase intervention is therefore required during porcine IVF.
|
