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. 2013 Jul 15;45(14):606-14.
doi: 10.1152/physiolgenomics.00021.2013. Epub 2013 May 28.

Selectively bred rat model system for low and high response to exercise training

Lauren Gerard Koch  1 , Geoffrey E Pollott, Steven L Britton
Affiliations

Selectively bred rat model system for low and high response to exercise training

Lauren Gerard Koch et al. Physiol Genomics. .

Abstract

We initiated a large-scale bidirectional selection experiment in a genetically heterogeneous rat population (N/NIH stock, n = 152) to develop lines of low response trainers (LRT) and high response trainers (HRT) as a contrasting animal model system. Maximal treadmill running distance [meters (m)] was tested before (DIST(1)) and after (DIST(2)) standardized aerobic treadmill training over an 8 wk period (3 exercise sessions per week). Response to training was calculated as the change in exercise capacity (ΔDIST = DIST(2) - DIST(1)). A within-family selection and rotational breeding paradigm between 10 families was practiced for both selected lines. For the founder population, exercise training produced a 140 ± 15 m gain in exercise capacity with interindividual variation ranging from -339 to +627 m. After 15 generations of selection (n = 3,114 rats), HRT rats improved 223 ± 20 m as a result of exercise training while exercise capacity declined -65 ± 15 m in LRT rats given the same absolute training environment. The narrow-sense heritability (h(2)) for ΔDIST was 0.10 ± 0.02. The LRT and HRT lines did not differ significantly for body weight or intrinsic (i.e., DIST(1)) exercise capacity. Using pedigree records the inbreeding coefficient increased at a rate of 1.7% per generation for HRT and 1.6% per generation for LRT, ∼30% slower than expected from random mating. Animal models developed from heterogeneous stock and enriched via selection, as presented here, often generate extreme values for traits of interest and may prove more useful than current models for uncovering genetic underpinnings.

Keywords: aerobic capacity; exercise training response; gene-environment interaction; inbred strains.

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Figures

Fig. 1.
Fig. 1.
Response to exercise training in a rat population made up of 10 different inbred strains (population 1). A: distribution for the change in running capacity (ΔDIST) plotted for 117 individual rats arranged in ascending order. D'Agostino and Pearson omnibus normality test; P > 0.05. B: ΔDIST separated by strain arranged in ascending order. Strains significantly different from each other are denoted by same letter (1-way ANOVA, Tukey; *P < 0.05, ^P < 0.01). Data include both females and males combined.
Fig. 2.
Fig. 2.
Response to exercise training in genetically heterogeneous rat populations as part of a large-scale selective breeding program for low and high response to training (population 2). A: frequency distribution for the ΔDIST for 152 nonselected N/NIH rats shown in ascending order. The brackets indicate the lowest and highest 10th percentile animals that were used as founders to start the low response trainer (LRT) and high response trainer (HRT) selected lines. Dotted line indicates the mean change in running capacity for population 2. B: percentile rank score for the ΔDIST for 178 rats from generation 15 of selection arranged from lowest to highest. Light bars indicate LRT animals, and dark bars indicate HRT animals. Dotted lines indicate the mean change in running capacity for the LRT (light) and HRT (dark) selected lines. D'Agostino and Pearson omnibus normality test; P > 0.05.
Fig. 3.
Fig. 3.
Response to selection across 15 generations for low and high exercise training capacity (population 3). A: phenotypic trend for ΔDIST across 15 generations of selection for low and high response to training. Mean of the founder population is plotted at generation 0 (box symbol). B: genotypic trend. Each point represents the mean genetic value for ΔDIST represented as estimated breeding values (EBV) for each generation. For both A and B, LRT line shown with light line and HRT line shown with dark line. Dashed line is the difference between the low and high selected lines.
Fig. 4.
Fig. 4.
Phenotypic and genotypic trends for intrinsic and trained running capacity across 15 generations of selection (population 3). A: intrinsic capacity (DIST1, m) phenotypically increased for both LRT and HRT lines across generations as a correlated response to selection but were not different from each other. No genotypic trends (EBV) for DIST1 were revealed across selection in either line. B: trained capacity (DIST2, m) diverged phenotypically between LRT and HRT as a function of selection on ΔDIST. Genotypic trend (EBV) for DIST2 also diverged between LRT and HRT across selection. LRT (light lines) and HRT (dark lines). Mean of the founder population is plotted at generation 0 (box symbol).
Fig. 5.
Fig. 5.
Level of inbreeding across 15 generations of selection (population 3). Mean inbreeding proportions are shown for LRT (light, diamond symbols) and HRT (dark, box symbols) lines. Fitting a linear regression model showed inbreeding increasing at an average rate of 0.017 and 0.016 per generation for the HRT and LRT lines, respectively.
Fig. 6.
Fig. 6.
DIST1 and DIST2 for 2 populations of selected lines and 2 populations of nonselected lines. The selection process often carries the phenotypic means beyond the range of a founder population. Plotted are mean (± SE) values for DIST1 (m) vs. DIST2 (m) capacity for: 1) 10 different inbred strains (Fig. 1, population 1 rats), 2) genetically heterogeneous N/NIH rats (Fig. 2A, population 2 rats), 3) rats selectively bred for low and high response to exercise training, LRT and HRT (population 3, generation 12), and 4) rats selectively bred for low and high intrinsic running capacity, LCR and HCR (generation 12). Invariably the selected lines comprised the extreme values for capacity for both intrinsic and trained conditions. Data plotted as linear regression [dotted lines show 95% confidence intervals (CI)] and are compared with a line of identity (DIST1 = DIST2). y = 0.98x + 98.4, R2 = 0.73, CI95 = 0.60 to 1.4. *Inbred strains represented in N/NIH outbred stock. Data shown are for males and females combined.
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References

    1. Albert FW, Carlborg O, Plyusnina I, Besnier F, Hedwig D, Lautenschlager S, Lorenz D, McIntosh J, Neumann C, Richter H, Zeising C, Kozhemyakina R, Shchepina O, Kratzsch J, Trut L, Teupser D, Thiery J, Schoneberg T, Andersson L, Paabo S. Genetic architecture of tameness in a rat model of animal domestication. Genetics 182: 541–554, 2009 - PMC - PubMed
    1. Blair SN, Kampert JB, Kohl HW, 3rd, Barlow CE, Macera CA, Paffenbarger RS, Jr, Gibbons LW. Influences of cardiorespiratory fitness and other precursors on cardiovascular disease and all-cause mortality in men and women. JAMA 276: 205–210, 1996 - PubMed
    1. Blair SN, Kohl HW, 3rd, Barlow CE, Paffenbarger RS, Jr, Gibbons LW, Macera CA. Changes in physical fitness and all-cause mortality A prospective study of healthy and unhealthy men. JAMA 273: 1093–1098, 1995 - PubMed
    1. Blair SN, Kohl HW, 3rd, Paffenbarger RS, Jr, Clark DG, Cooper KH, Gibbons LW. Physical fitness and all-cause mortality A prospective study of healthy men and women. JAMA 262: 2395–2401, 1989 - PubMed
    1. Bouchard C, An P, Rice T, Skinner JS, Wilmore JH, Gagnon J, Perusse L, Leon AS, Rao DC. Familial aggregation of VO2 max response to exercise training: results from the Heritage family study. J Appl Physiol 87: 1003–1008, 1999 - PubMed

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