| Project/Area Number |
17580245
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied animal science
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| Research Institution | Utsunomiya University |
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Principal Investigator |
YOSHIZAWA Midori Utsunomiya University, Faculty of Agriculture, Professor (60114162)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUI Emiko Utsunomiya Univ., Faculty of Agriculture, associate Professor (20208341)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,960,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥360,000)
Fiscal Year 2007: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Chromosomal Abnormalities / Nuclear Transfer / In Vitro Fertilization / Meiosis II / Mouse / M-II期核置換 / 胚発生能 / 半数体 / 低倍数体 / 多倍体 |
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| Research Abstract |
Firstly, the present study compared the use of two temperatures (fusion at 37 and 25 degrees C) during an electrofusion procedure for mouse oocyte meiosis-II chromosomes (M-II-t) and investigated cytogenetic normality and developmental competence of the embryos derived from in vitro fertilization (IVF) using oocytes reconstructed by M-II-t. A temperature of 25 degrees C during the electrofusion procedure for M-II-t resulted in a good fusion rate, a good development rate, and efficiently produced, chromosomally normal blastocysts. Furthermore, the incidence of chromosomal abnormalities in the first cleavage embryos at the prometaphase stage in the 25 degree Group (9.6%) did not differ significantly from that in the control group (6.6%). Spindle morphology in the M-II-t oocytes of the 25 degree Group was normal.
Secondary, the effects of reciprocal transplantation of meiosis-II chromosomes (M-II-t) between senescent and young mouse oocytes were evaluated based on pre- and post-implantation development ability of resultant embryos. The reconstructed oocytes that consisted of aged karyoplasts and young-cytoplasts showed significantly improved embryonic development (from 23.2% to 30.0%) and development to term (from 6.3% to 27.1%, P<0.05) as compared with the oocytes reconstructed from young-karyoplasts and aged-cytoplasts. The present study showed successful rejuvenation for age-related infertility using M-II-t in animal experimental models.
For reciprocal transplantation of germinal vesicles between senescent and young mouse oocytes, the methodology was established in the present study but the final cytogenetical analysis of resultant embryos is studying as an ongoing research now.
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