| Project/Area Number |
08672597
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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 |
Human genetics
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
MATSUURA Shinya Research Institute for Radiation Biology and Medicine, Hiroshima University, Research Associate, 原爆放射能医学研究所, 助手 (90274133)
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| Co-Investigator(Kenkyū-buntansha) |
KOMATSU Kenshi Research Institute for Radiation Biology and Medicine, Hiroshima University, Pro, 原爆放射能医学研究所, 教授 (80124577)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Model mouse / Xist / X inactivation / Counting mechanism / transgenic mouse / microinjection |
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| Research Abstract |
We have constructed mouse transgenic lines carrying a YAC clone encompassing the Xist gene in order to investigate the factors influencing Xist expression and the initiation of X-inactivation. Two transgenic lines were derived - one carrying 4 copies integrated at an autosomal site and a second line carrying 4 copies integrated at a single site on the Y chromosome. Xist expression was not observed in mice carrying the autosomal insertion. However, Xist expression from the Y-inserted transgenes was observed and at levels commensurate with that found in normal female mice. Methylation sites in the autosomal transgene both 5' and 3' of the Xist gene are hyjpermethylated and appear to reflect methylation patterns observed on the active X chromosome. For the Y-linked transgene, methylation sites 5' and 3' of the Xist gene are hypomethylated feflecting patterns found on the inactive X chromosome. However, the 5' and 3' methylation levels have been decoupled at the active transgenic locus.
As beta-geo reporter gene had been retrofitted on the YAC right arm, we have then analyzed beta-geo expression in Tg15 mouse embryos on the basis of LacZ staining. One cell stage embryos were not stained with X-gal. LacZ staining appeared at 2-4 cells stage, and strong staining was detected at morula stage. However, after blastcyst stage, embryos were not stained. The data might suggest that sequences in the vicinity of Xist can initiate some phenomenon associated with the process of X-inactivation.
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