| Project/Area Number |
09670280
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Bacteriology (including Mycology)
|
|---|
| Research Institution | Okayama Prefectural University (1998)
Osaka University (1997) |
|---|
Principal Investigator |
YAMAMOTO Koichiro Okayama Pref.Univ., Fac.Health Welfare Sci., Professor, 保健福祉学部, 教授 (30158274)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ARITA Michiko Okayama Pref.Univ., Fac.Health Welfare Sci., Research Associate, 保健福祉学部, 助手 (10127178)
HONDA Takeshi Osaka Univ., Res.Inst.Microbial Dis., Professor (60029808)
IIDA Tetsuya Osaka Univ., Res.Inst.Microbial Dis., Associate Professor (90221746)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Project Status |
Completed (Fiscal Year 1998)
|
| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
|
|---|
| Keywords | Phospholipase / Vibrio cholerae / toxin / Gene / choromosome / lypA / ctxAB / toxR |
|---|
| Research Abstract |
By pulse-field electrophoresis and Southern hybridization, we found the lypA band toxR geneswere in the same NotI DNA fragment of Vibrio cholerae chromosome. This suggest close proximity between lypA and toxR.
Insertional mutants in the lypA gene was constructed using suicide vector containing inner fragment of the lypA gene. Cholera toxin-producing ability was reduced in these insertional mutants, especially in the strain which highly produces the toxin, such as strain 569B.In the insertional mutant strain which reduced production of cholera toxin, transcription of toxR was also down-regulated.
We deleted the lypA gene completely by double-crossover recombination. In this deletion mutant, production of cholera toxin and transcription of toxR were not reduced clearly. This suggest that insertion of plasmid into the lypA in the insertional mutant may affect the neighboring genes, which affect production of cholera toxin.
|
