1994 Fiscal Year Final Research Report Summary
Expression of muscle protein genes in cardiac and skeletal muscles during development
| Project/Area Number |
04670005
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Chiba University |
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Principal Investigator |
TOYOTA Naoji Chiba University, Medical School Lecturer, 医学部, 講師 (00188822)
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| Co-Investigator(Kenkyū-buntansha) |
KOMIYAMA Masatoshi Chiba University, Medical School Research Associate, 医学部, 助手 (70175339)
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| Project Period (FY) |
1992 – 1994
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| Keywords | expression / gene / mRNA / post-transcriptional control / protein |
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| Research Abstract |
We have analyzed the expression of troponin C and I(TnC and I,respectively)genes at the mRNA and protein levels in cardiac and skeletal muscles of embryonic and adult chickens using DNA and antibody probes.
At stage 10 (Hamburger and Hamilton numbering) , both C/STnC mRNA and protein were detected in the ventricle, the truncus arteriosus and the vitelline vein. At stage 14, in addition to these regions, they were also identified in somites. In adult animals, although C/STnC mRNA was present in the breast muscle, C/STnC protein was undetectable in this muscle (Toyota and Shimada : J.Cell Biol.91,497-504,1981). The imbalance of C/STnC mRNA and protein levels suggests the operation of specific mechanisms that separately regulate the accumulation of CTnC mRNA and protein in the adult breast muscle.
FTnC mRNA and protein were identified in somites and the adult breast muscle. They were absent in the ventricle and the vitelline vein throughout development and in adult animals. However, FTnC mRNA was found in the truncus arteriosus at stage 20, but it was undetectable in this area at any other developmental stages. FTnC protein was absent in this region throughout development. This suggests that the expression of FTnC mRNA in the truncus arteriosus is the stage- and region-specific and that the different mechanism regulates the transcription of FTnC mRNA in different regions of the developing cardiac tube.
CTnI mRNA and protein were detected in embryonic and adult cardiac muscles but not in somites and the adult breast muscle. The pattern of CTnI mRNA transcription corresponded with that of CTnI protein expression.
These results showed that the diverse gene regulatory mechanisms direct the expression of Tn genes in different muscles and those at different stages.
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