Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-1-6
pubmed:abstractText
This comparative study of myonuclear domain (MND) size in mammalian species representing a 100,000-fold difference in body mass, ranging from 25 g to 2500 kg, was undertaken to improve our understanding of myonuclear organization in skeletal muscle fibres. Myonuclear domain size was calculated from three-dimensional reconstructions in a total of 235 single muscle fibre segments at a fixed sarcomere length. Irrespective of species, the largest MND size was observed in muscle fibres expressing fast myosin heavy chain (MyHC) isoforms, but in the two smallest mammalian species studied (mouse and rat), MND size was not larger in the fast-twitch fibres expressing the IIA MyHC isofom than in the slow-twitch type I fibres. In the larger mammals, the type I fibres always had the smallest average MND size, but contrary to mouse and rat muscles, type IIA fibres had lower mitochondrial enzyme activities than type I fibres. Myonuclear domain size was highly dependent on body mass in the two muscle fibre types expressed in all species, i.e. types I and IIA. Myonuclear domain size increased in muscle fibres expressing both the beta/slow (type I; r = 0.84, P < 0.001) and the fast IIA MyHC isoform (r = 0.90; P < 0.001). Thus, MND size scales with body size and is highly dependent on muscle fibre type, independent of species. However, myosin isoform expression is not the sole protein determining MND size, and other protein systems, such as mitochondrial proteins, may be equally or more important determinants of MND size.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1469-445X
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
94
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
117-29
pubmed:meshHeading
pubmed-meshheading:18820003-Animals, pubmed-meshheading:18820003-Body Mass Index, pubmed-meshheading:18820003-Body Size, pubmed-meshheading:18820003-DNA, pubmed-meshheading:18820003-Female, pubmed-meshheading:18820003-Horses, pubmed-meshheading:18820003-Humans, pubmed-meshheading:18820003-Male, pubmed-meshheading:18820003-Mice, pubmed-meshheading:18820003-Mice, Inbred C57BL, pubmed-meshheading:18820003-Muscle Fibers, Fast-Twitch, pubmed-meshheading:18820003-Muscle Fibers, Slow-Twitch, pubmed-meshheading:18820003-Myosin Heavy Chains, pubmed-meshheading:18820003-Perissodactyla, pubmed-meshheading:18820003-Protein Isoforms, pubmed-meshheading:18820003-Rats, pubmed-meshheading:18820003-Rats, Sprague-Dawley, pubmed-meshheading:18820003-Species Specificity, pubmed-meshheading:18820003-Swine, pubmed-meshheading:18820003-Young Adult
pubmed:year
2009
pubmed:articleTitle
Myonuclear domain size and myosin isoform expression in muscle fibres from mammals representing a 100,000-fold difference in body size.
pubmed:affiliation
Department of Neurosciences, Uppsala University, Uppsala, Sweden.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural