1991 Fiscal Year Final Research Report Summary
Molecular analysis of gene abnormalities in myasthenia gravis.
| Project/Area Number |
02454224
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
内科学一般
|
|---|
| Research Institution | Tokai University School of Medicine |
|---|
Principal Investigator |
ARIMORI Shigeru Tokai University School of Medicine 4th Internal Medicine, Professor, 医学部, 教授 (00033093)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MORIUCHI Tetsuya Tokai University School of Medicine Cell Biology, Associate Professor, 医学部, 助教授 (20174394)
|
|---|
| Project Period (FY) |
1990 – 1991
|
| Keywords | myasthenis gravis / acetylcholine receptor delta / gamma subunit / thymoma / サテライトDNA |
|---|
| Research Abstract |
1. Genomic DNAs of Japanese healthy individuals were digested with endonuclease Kpn I, Pst I, Pvu II, Hint I, and Sac I. Southern blot analysis of these DNA digests was performed by using calf acetylcholine delta/gamma subunit CDNA as a probe.
DNA polymorphysm was found only in Pvu II-digested DNAs (1.7 kb and 1.9 kb bands) in Japanese. The frequency of 1.7 kb/1.7 kb was 85% (83/98) and of 1.7 kb/1.9 kb was 15% (15/98). The frequencies of these bands in Japanese myasthenia gravis patients were 88% and 12%, respectively. Statistically significant association was not demonstrated between myasthenia gravis and RFLPs of acetylcholine receptor delta/gamma subunit gene.
2. BUF/Mna rats develop spontaneous benign thymomas of epithelial origin with nearly 100% incidence. We purified satellite I DNA from BUF/Mna rat thymoma and constructed recombinant plasmid library. We screened 1200 clones by using satellite I DNA probe and isolated 4 unusual clones. Nucleotide sequence analysis of these clones revealed many deletions, insertions and base substitutions, and these mutations created unusual repeat units. The unusual structures of satellite I DNA subunit were created by change of Hint I sequence to Eco RI sequence in monomeric and dimeric-subunit. The nucleotide sequence TGGGAAC, which is strictly conserved in normal repeat unit was completely lost in all these clones. Control experiment was done in ACI rat DNA. Out of 1200 clones examined, no unusual satellite I DNA sequence was found. The generation of abnormal satellite I DNA may provide the molecular basis of chromosome instability in thymoma cells of BUF/Mna rats.
|
