Cell size as a link between noncoding DNA and metabolic rate scaling
Cell size as a link between noncoding DNA and metabolic rate scaling
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DOI：
10.1073/pnas.2334605100
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发表时间：
2003-11-25
影响因子：
11.1
通讯作者：
Gawelczyk, AT
中科院分区：
文献类型：
--
作者：
Kozlowski, J;Konarzewski, M;Gawelczyk, AT
非编码DNA的积累和基因组大小（c值）可能在低代谢成本的情况下朝着增加体型的强烈选择下发生。c值直接间接影响细胞大小和特定代谢率。体型可以通过细胞大小和/或细胞数量的增加而增大，小细胞代谢率较高。我们认为，代谢率的种间异速指数是在狭窄的分类群体中c值进化多样化的副产品，这强调了细胞大小和细胞数量在体型优化中的作用。这种优化导致种间代谢速率异速斜率与c值呈反比关系。为了验证这一预测，我们分别提取了6目哺乳动物和8目鸟类的基础代谢率（BMR）、体重和c值的文献数据。协方差分析显示，哺乳动物和鸟类的BMR异速斜率和c值具有显著的异质性。正如我们预测的那样，在哺乳动物和鸟类目中，BMR异速生长指数与c值呈负相关且具有统计学意义。
Accumulation of noncoding DNA and therefore genome size (C-value) may be under strong selection toward increase of body size accompanied by low metabolic costs. C-value directly affects cell size and specific metabolic rate indirectly. Body size can enlarge through increase of cell size and/or cell number, with small cells having higher metabolic rates. We argue that scaling exponents of interspecific allometries of metabolic rates are by-products of evolutionary diversification of C-values within narrow taxonomic groups, which underlines the participation of cell size and cell number in body size optimization. This optimization leads to an inverse relation between slopes of interspecific allometries of metabolic rates and C-value. To test this prediction we extracted literature data on basal metabolic rate (BMR), body mass, and C-value of mammals and birds representing six and eight orders, respectively. Analysis of covariance revealed significant heterogeneity of the allometric slopes of BMR and C-value in both mammals and birds. As we predicted, the correlation between allometric exponents of BMR and C-value was negative and statistically significant among mammalian and avian orders.