2000 Fiscal Year Final Research Report Summary
Gene Regulation in Cardiac Development
Project/Area Number |
11838009
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Institution | Osaka University |
Principal Investigator |
MIWA Takeshi Genome Information Research Center, Osaka University, Associate Professor, 遺伝情報実験施設, 助教授 (20174229)
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Co-Investigator(Kenkyū-buntansha) |
TAKIHARA Yoshihiro Research Institute for Microbial Diseases, Osaka University Associate Professor, 微生物病研究所, 助教授 (60226967)
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Project Period (FY) |
1999 – 2000
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Keywords | transcriptional factor / cre-loxP / transgenic mice / polycomb |
Research Abstract |
To understand the mechanisms of smooth muscle (SM) cell differentiation, we are analyzing the transcriptional regulation system of human smooth muscle a-actin (SmaA) gene. We made several transgenic mice having the upstream region from the transcription initiation site and the first intron region following a CAT gene. The transgenic mice having the both regions (EA4.7-CAT and 123int-CAT) showed very strong CAT expressions in aorta, heart and intestine, but weak in liver, skeletal muscle. Using histochemical stains by CAT-activity and CAT-antibody, CAT is detected only in tunica media in artery and SM layer in gastrointestinal tract, where intrinsic SmaA are expressed. Whereas, the transgenic mice deleting the 137-bp region in intron 1 (D#0-CAT) which is highly conserved among several species (human, mouse and chick) showed weak CAT expression in all tissues we examined. Therefore, it is showed that the 137-bp sequence is necessary for SM tissue-specific expression in adult mice. In the 137-bp region, one CArG box element (#0) and A/TBF binding element whose motif is ATTA sequence locate overlaply and nuclear factors, SRF and A/TBF, can bind to each element independently. To test whether these two elements are important for SM tissue-specific in vivo expression, point mutants (-1M and 4M) are introduced into each element and measured promoter activities in mouse embryos. At 11.5 dpc embryos, the wild-type SmaA promoter (hSmaA-lacZ) worked in aorta, heart and diencephalon whereas the mutated promoters in both elements worked in heart and diencephalon but not in aorta. From these results, CArG box and A/TBF binding elements in the intron 1 of the SmaA gene are very important for SM tissue-specific in vivo expression.
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Research Products
(8 results)