HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 100/6/2024    most recent 00913.2005v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Bruusgaard, J. C. Articles by Gundersen, K. Search for Related Content PubMed PubMed Citation Articles by Bruusgaard, J. C. Articles by Gundersen, K.

Distribution of myonuclei and microtubules in live muscle fibers of young, middle-aged, and old mice

¹Department of Molecular Biosciences and ²Informatics, University of Oslo, Oslo, Norway

Submitted 28 July 2005 ; accepted in final form 13 February 2006

We have recently published a new technique for visualizing nuclei in living muscle fibers of intact animals, based on microinjection of labeled DNA into single myofibers, excluding satellite cells (Bruusgaard JC, Liestol K, Ekmark M, Kollstad K, and Gundersen K. J Physiol 551: 467–478, 2003). In the present study, we use this technique to study fiber segments of soleus and extensor digitorum longus (EDL) muscles from mice aged 2, 14, and 23 mo. As the animals maturing from 2 to 14 mo, they displayed an increase in size and number of nuclei. Soleus showed little change in nuclear domain size, whereas this increased by 88% in the EDL. For 14-mo-old animals, no significant correlation between fiber size and nuclear number was observed (R² = 0.18, P = 0.51) despite a fourfold variation in cytoplasmic volume. This suggests that size and nuclear number is uncoupled in middle-aged mice. When animals aged from 14 to 23 mo, EDL IIb, but not soleus, fibers atrophied by 41%. Both EDL and soleus displayed a reduction in number of nuclei: 20 and 16%, respectively. A positive correlation between number of nuclei and size was observed at 2 mo, and this reappeared in old mice. The atrophy in IIb fibers at old age was accompanied by a disturbance in the orderly positioning of nuclei that is so prominent in glycolytic fibers at younger age. In old animals, changes in nuclear shape and in the peri- and internuclear microtubule network were also observed. Thus changes in myonuclear number and distribution, perhaps related to alterations in the microtubular network, may underlie some of the adverse consequences of aging on skeletal muscle size and function.

skeletal; nuclei; aging; domains; sarcopenia; cytoskeleton; atrophy

This article has been cited by other articles:

				K. M. Hardy, R. M. Dillaman, B. R. Locke, and S. T. Kinsey A skeletal muscle model of extreme hypertrophic growth reveals the influence of diffusion on cellular design Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2009; 296(6): R1855 - R1867. [Abstract] [Full Text] [PDF]

				J.-X. Liu, A.-S. Hoglund, P. Karlsson, J. Lindblad, R. Qaisar, S. Aare, E. Bengtsson, and L. Larsson Myonuclear domain size and myosin isoform expression in muscle fibres from mammals representing a 100 000-fold difference in body size Exp Physiol, January 1, 2009; 94(1): 117 - 129. [Abstract] [Full Text] [PDF]

				D. L. Yamamoto, R. I. Csikasz, Y. Li, G. Sharma, K. Hjort, R. Karlsson, and T. Bengtsson Myotube Formation on Micro-patterned Glass: Intracellular Organization and Protein Distribution in C2C12 Skeletal Muscle Cells J. Histochem. Cytochem., October 1, 2008; 56(10): 881 - 892. [Abstract] [Full Text] [PDF]

				K. Gundersen and J. C. Bruusgaard Nuclear domains during muscle atrophy: nuclei lost or paradigm lost? J. Physiol., June 1, 2008; 586(11): 2675 - 2681. [Abstract] [Full Text] [PDF]

				C. B. Mantilla, R. V. Sill, B. Aravamudan, W.-Z. Zhan, and G. C. Sieck Developmental effects on myonuclear domain size of rat diaphragm fibers J Appl Physiol, March 1, 2008; 104(3): 787 - 794. [Abstract] [Full Text] [PDF]

				N. T. Swailes, M. Colegrave, P. J. Knight, and M. Peckham Non-muscle myosins 2A and 2B drive changes in cell morphology that occur as myoblasts align and fuse J. Cell Sci., September 1, 2006; 119(17): 3561 - 3570. [Abstract] [Full Text] [PDF]