Developmentally regulated slow troponin C messenger RNA in chicken skeletal and cardiac muscles.
Regulation of slow troponin C gene expression was examined in both skeletal and cardiac muscle at various stages of development in chicken. The steady-state levels of troponin C mRNA were initially measured by Northern blot analysis. It was observed that the level of troponin C mRNA reached its maximum in both skeletal and cardiac muscle of 16- to 18-day-old embryos. A drop in troponin C mRNA level was observed just prior to hatching. The level of actin mRNA, myosin heavy chain mRNA, and mRNA for a nonmuscle protein, vimentin, was also similarly regulated during development of chicken muscles. Further studies were carried out to determine the level of slow troponin C mRNA using nuclease S1 protection analysis. A significant amount of slow troponin C mRNA was found in the skeletal muscle of adult chicken, which predominantly consists of the fast isoform of troponin C. This observation suggests the possibility of post-transcriptional control of slow troponin C synthesis in skeletal muscle. Primary cultures of cardiac myocytes were also used to determine how the troponin C mRNA level is regulated in a culture of cardiac muscle cells. Measurements of the steady-state levels of slow troponin C mRNA by nuclease S1 protection analysis show that it was maximal in 60-h-old cultures. A drop in the level of this mRNA was observed after these cells were maintained in culture for 4 days.
Berezowsky
C
C
University of Guelph, Department of Molecular Biology and Genetics, Ont., Canada.
Bag
J
J
D000199:Actins / Q000235:genetics; D000375:Aging / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D015342:DNA Probes; D004591:Electrophoresis, Polyacrylamide Gel; D004720:Endonucleases; D005786:Gene Expression Regulation; D006321:Heart / Q000196:embryology / Q000254:growth & development*; D024510:Muscle Development; D009132:Muscles / Q000196:embryology / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009218:Myosins; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism*; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014336:Troponin / Q000235:genetics*; D019209:Troponin C; D014746:Vimentin / Q000235:genetics
D000199:Actins; D015342:DNA Probes; D012333:RNA, Messenger; D014336:Troponin; D019209:Troponin C; D014746:Vimentin; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases; D009218:Myosins