In:
Physiological Genomics, American Physiological Society, Vol. 45, No. 6 ( 2013-03-15), p. 228-236
Abstract:
Few studies have investigated heterogeneity of selection response in replicate lines subjected to equivalent selection. We developed four replicate lines of mice based on high levels of voluntary wheel running (high runner or HR lines) while also maintaining four nonselected control lines. This led to the unexpected discovery of the HR minimuscle (HR mini ) phenotype, recognized by a 50% reduction in hindlimb muscle mass, which became fixed in 1 of the four HR selected lines. Here, we report genome-wide expression profiling describing transcriptome differences between HR normal and HR mini medial gastrocnemius. Consistent with the known reduction of type IIB fibers in HR mini , Myh4 gene expression was −8.82-fold less ( P = 0.0001) in HR mini , which was closely associated with differences in the “calcium signaling” canonical pathway, including structural genes (e.g., Mef2c, twofold greater in HR mini , P = 0.0003) and myogenic factors (e.g., Myog, 3.8-fold greater in HR mini , P = 0.0026) associated with slow-type myofibers. The gene that determines the HR mini phenotype is known to reside in a 2.6335-Mb interval on mouse chromosome 11 and 7 genes ( Myh10, Chrnb1, Acadvl, Senp3, Gabarap, Eif5a, and Clec10a) from this region were differentially expressed. Verification by real-time PCR confirmed 1.5-fold greater ( P 〈 0.05) expression of very long chain acyl-CoA dehydrogenase ( Acadvl) in HR mini . Ten other genes associated with fatty acid metabolism were also upregulated in HR mini , suggesting differences in the ability to metabolize fatty acids in HR normal and HR mini muscles. This work provides a resource for understanding differences in muscle phenotypes in populations exhibiting high running capacity.
Type of Medium:
Online Resource
ISSN:
1094-8341
,
1531-2267
DOI:
10.1152/physiolgenomics.00149.2012
Language:
English
Publisher:
American Physiological Society
Publication Date:
2013
detail.hit.zdb_id:
2031330-5
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