Sorrells Trevor R, Johnson Alexander D
Department of Biochemistry & Biophysics and Department of Microbiology & Immunology, Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.
Department of Biochemistry & Biophysics and Department of Microbiology & Immunology, Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.
Cell. 2015 May 7;161(4):714-23. doi: 10.1016/j.cell.2015.04.014.
When transcription regulatory networks are compared among distantly related eukaryotes, a number of striking similarities are observed: a larger-than-expected number of genes, extensive overlapping connections, and an apparently high degree of functional redundancy. It is often assumed that the complexity of these networks represents optimized solutions, precisely sculpted by natural selection; their common features are often asserted to be adaptive. Here, we discuss support for an alternative hypothesis: the common structural features of transcription networks arise from evolutionary trajectories of "least resistance"--that is, the relative ease with which certain types of network structures are formed during their evolution.
当在亲缘关系较远的真核生物之间比较转录调控网络时，会观察到许多显著的相似之处：基因数量比预期的多、广泛的重叠连接以及明显高度的功能冗余。人们常常认为这些网络的复杂性代表了经过自然选择精确塑造的优化解决方案；它们的共同特征通常被认为是适应性的。在这里，我们讨论对另一种假设的支持：转录网络的共同结构特征源于“阻力最小”的进化轨迹——也就是说，某些类型的网络结构在其进化过程中形成的相对容易程度。
