转录噪音
转录噪音(Transcriptional noise)为近等基因细胞群体中各个细胞转录差异产生的主要原因(参见细胞噪音)[1]。人们认为,转录噪音的一个诱因为转录暴增[2][3][4],不过其他异质性诱因,比如细胞在有丝分裂过程中发生的不等分裂,也可能在相当程度上诱发了转录噪音[5]。暴增的转录,和转录简单的概率模型不同,反映了不定期来回波动的基因活性的多样状态。这在细胞之间产生了蛋白质表达的差异。基因表达的噪音对细胞行为有着巨大的影响,而且,这种噪音不是达到协调统一的状态,就是逐渐减弱。在某些情况下,比如微生物要在多变的环境中生存,或者于几种散分化中,这样的变化是不可或缺的[6]。这样的变化亦对临床治疗的效果产生影响,比如细菌可能因为非遗传学的原因对抗生素产生抗药性[7]。基因表达的变化亦可增强癌细胞亚群对化疗的抵抗力[8]。
参考
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