Expression of chicken troponin T isoforms in cultured muscle cells.
Cells prepared from chicken skeletal muscles of different developmental stages were cultured to study their troponin T isoform expression, using antisera specific to the fast- and slow-muscle-type isoforms. We found that the cultured myogenic cells from chickens and chick embryos were classified into two types, fast type and fast/slow type in which fast- and slow-muscle-type isoforms were coexpressed. Cells expressing only slow-muscle-type troponin T isoforms could not be found. Most cells prepared from pectoralis major (fast muscle) and gastrocnemius (mixed muscle) of 11-day old embryos belonged to the latter, with only a small fraction belonging to the former. The percentage of fast type cells in those cells prepared from pectoralis major increased along development to over 90% by the 17th day of incubation, while, in the cells prepared from gastrocnemius, it reached a plateau of 30-40% by the 13th day of incubation. All the cells from anterior latissimus dorsi (slow muscle) belonged to the fast/slow type. Ratios of these two types of muscle cells varied depending on their origins and stages. The in vitro expression of troponin T isoforms was different from the in vivo expression, and each muscle seems to be determined differently in the composition of cell types during the developmental course.
Mashima
J
J
Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.
Nakada
K
K
Yao
Y
Y
Miyazaki
J
J
Hirabayashi
T
T
D000818:Animals; D002478:Cells, Cultured; D002645:Chickens; D007106:Immune Sera; D007150:Immunohistochemistry; D007536:Isomerism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D014336:Troponin / Q000276:immunology / Q000378:metabolism*; D020107:Troponin T
D007106:Immune Sera; D014336:Troponin; D020107:Troponin T