Cold acclimation and endurance training in guinea pigs: changes in lung, muscle and brown fat tissue

Maximal metabolic outputs for exercise and thermogenesis in birds presumably influence fitness through effects on flight and shivering performance. Because both summit (M sum , maximum thermoregulatory metabolic rate) and maximum (MMR, maximum exercise metabolic rate) metabolic rates are functions of skeletal muscle activity, correlations between these measurements and their mechanistic underpinnings might occur. To examine whether such correlations occur, we measured the effects of experimental cold and exercise training protocols for 3 weeks on body (M b ) and muscle (M pec ) masses, basal metabolic rate (BMR), M sum , MMR, pectoralis mRNA and protein expression for myostatin, and mRNA expression of TLL-1 and TLL-2 (metalloproteinase activators of myostatin) in house sparrows (Passer domesticus). Both training protocols increased M sum , MMR, M b and M pec , but BMR increased with cold training and decreased with exercise training. No significant differences occurred for pectoralis myostatin mRNA expression, but cold and exercise increased the expression of TLL-1 and TLL-2. Pectoralis myostatin protein levels were generally reduced for both training groups. These data clearly demonstrate cross-training effects of cold and exercise in birds, and are consistent with a role for myostatin in increasing pectoralis muscle mass and driving organismal increases in metabolic capacities.

Section: Among Birds Tufted Duckssupporting

confidence: 75%

Cross-training in birds: cold and exercise training produce similar changes in maximal metabolic output, muscle masses and myostatin expression in house sparrows,Passer domesticus

Zhang

Eyster

Liu

et al. 2015

“…Adult vertebrate lung also seems to have relatively low plasticity (e.g. Hoppeler et al, 1995;Weibel, 2000;Hsia, 2001;Henderson et al, 2002).…”

Section: Comparative Studiesmentioning

confidence: 99%

Phenotypic plasticity and experimental evolution

Garland

Kelly

2006

273

140

There were two errors published in J. Exp. Biol. 209, 2344-2361 First, on p. 2355 in the first complete paragraph of the section entitled 'Plasticity of exercise-related traits', the authors stated:If we imagine further that S and C mice housed without wheels showed no difference (or at least values similar to those of C mice housed with wheels), then the S mice seem to be more responsive to wheel exposure, i.e. they are more plastic.The sentence should have read:If we imagine further that S and C mice housed without wheels showed values similar to those of C mice housed with wheels, then the S mice seem to be more responsive to wheel exposure, i.e. they are more plastic.Second, on pp. 2355-2356, beginning in column 2 of p. 2355, the authors stated:For hematocrit in females, Table·2 shows that the ln likelihood of the nested ANCOVA model without wheel running (-75.7) is larger (less negative, in this case) than for the model with wheel running (-83.7). As the latter model contains one additional parameter (estimating the effect of wheel running), twice the difference in ln likelihoods (16.0, in this case) can be compared with a χ 2 distribution with one degree of freedom, for which the critical value for P=0.05 is 3.841. Therefore, the model with wheel running as an additional covariate yields a significantly worse fit to the data, and we conclude that the difference in hematocrit between S and C mice when housed with wheel access is not best explained as a simple function of the greater running by S mice.The paragraph should have read:For hematocrit in females, Table·2 shows that the ln likelihood of the nested ANCOVA model without wheel running is -78.1 whereas for the model with wheel running it is -77.9. As the latter model contains one additional parameter (estimating the effect of wheel running), twice the difference in ln likelihoods (0.3 in this case) can be compared with a χ 2 distribution with one degree of freedom, for which the critical value for P=0.05 is 3.841. Therefore, the model with wheel running as an additional covariate does not fit the data significantly better, and we conclude that the difference in hematocrit between S and C mice when housed with wheel access is not best explained as a simple function of the greater running by S mice.We apologise to the authors and readers for these errors but do not believe that they compromise the overall results and conclusions of the paper. Erratum 2344Introduction Natural selection tends to act most strongly on aspects of the phenotype (traits) at relatively high levels of biological organization because they are the most strongly correlated with Darwinian fitness (e.g. lifetime reproductive success). Components of life history, behaviors and aspects of organismal performance (for reviews, see Ketterson and Nolan, Jr, 1999;Irschick and Garland, Jr, 2001;Kingsolver and Huey, 2003;Costa and Sinervo, 2004) are 'complex traits' in that they are composed of many subordinate traits at lower levels of biological organization (Fig.·1). Thus, the evolutiona...

“…We previously reported an increase in muscle mitochondrial volume in short-tailed opossums, Monodelphis domestica . In contrast, in rodents possessing BAT, cold acclimation does not lead to alterations in muscle structure (Barre et al, 1987, Hoppeler et al, 1995.…”

mentioning

confidence: 99%

Cost of transport is increased after cold exposure inMonodelphis domestica: training for inefficiency

Schaeffer

Villarin

Pierotti

et al. 2005

control or exercise-trained animals, indicating greater oxidative capacity. Finally, we identified an uncoupling protein 3 homologue, whose gene expression was upregulated in skeletal muscle of cold-exposed Monodelphis domestica. Cold exposure provided a potent stimulus for muscle plasticity, driving a fast-to-slow transition more effectively than exercise training. However, linked to the dramatic shift in muscle properties is an equally dramatic increase in whole animal muscle energetics during locomotion, suggesting an uncoupled state, or 'training for inefficiency'.