Anatomic and energetic correlates of divergent selection for basal metabolic rate in laboratory mice
Anatomic and energetic correlates of divergent selection for basal metabolic rate in laboratory mice
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DOI：
10.1086/425190
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发表时间：
2004-11-01
影响因子：
1.6
通讯作者：
Lapo, IB
中科院分区：
文献类型：
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作者：
Ksiazek, A;Konarzewski, M;Lapo, IB
有氧代谢能力模型假定，与内温性相关的高基础代谢率（BMR）进化为对最大峰值代谢率（V）超过点o（2 max）的选择的相关反应。此外，该模型假设BMR和（V）over. o（2 max）是因果联系的，因此，它们的水平的进化变化不能独立发生。为了测试这一点，我们比较了F18和F19选择代的实验室小鼠雄性中高和低体重校正的BMR的选择的代谢和解剖学相关性。发散选择导致BMR的品系间差异相当于2.3个表型标准差单位。(V)在点O（2 max）上由强制引起。在20 ℃的水中游泳在低BMR系中比在高BMR系中更高，并且当暴露于-2.5 ℃的氦氧混合气中时，在系之间没有差异。此外，游泳和氦氧诱导的体温过低的幅度显着较小的低BMR小鼠，而他们的肩胛间棕色脂肪组织是大于高BMR小鼠。因此，我们的结果与有氧能力模型的预测存在差异。选择还导致食物消耗（C）和代谢活跃的内脏器官的质量的相关响应：肾脏、肝脏、小肠和心脏，其燃料最大持续代谢率（SusMR）而不是（V）超过点o（2 max）。这些相互关联的反应足以声称。基础代谢率与内脏质量和C.因此，我们的研究结果支持BMR进化为SusMR选择的相关反应，而不是（V）超过点o（2 max）。在功能方面，BMR。因此，应该被解释为维持高水平能量同化率所必需的代谢机制的能量成本的量度。
The aerobic capacity model postulates that high basal metabolic rates (BMR) associated with endothermy evolved as a correlated response to the selection on maximum, peak metabolic rate (V) over dot o(2max). Furthermore, the model assumes that BMR and (V) over dot o (2max) are causally linked, and therefore, evolutionary changes in their levels cannot occur independently. To test this, we compared metabolic and anatomical correlates of selection for high and low body mass - corrected BMR in males of laboratory mice of F18 and F19 selected generations. Divergent selection resulted in between-line difference in BMR equivalent to 2.3 phenotypic standard deviation units. (V) over dot o (2max) elicited by forced. swimming in 20 degreesC water was higher in the low BMR than high BMR line and did not differ between the lines when elicited by exposure to heliox at - 2.5 degreesC. Moreover, the magnitude of swim- and heliox-induced hypothermia was significantly smaller in low BMR mice, whereas their interscapular brown adipose tissue was larger than in high BMR mice. Our results are therefore at variance with the predictions of aerobic capacity model. The selection also resulted in correlated response in food consumption ( C) and masses of metabolically active internal organs: kidneys, liver, small intestine, and heart, which fuel maximum, sustained metabolic rate (SusMR) rather than (V) over dot o(2max). These correlated responses were strong enough to claim. the existence of positive, genetic correlations between BMR and the mass of viscera as well as C. Thus, our findings support the suggestion that BMR evolved as a correlated response to selection for SusMR, not (V) over dot o(2max). In functional terms BMR. should therefore be interpreted as a measure of energetic costs of maintenance of metabolic machinery necessary to sustain high levels of energy assimilation rate.