轉錄噪音

轉錄噪音(Transcriptional noise)爲近等基因細胞群體中各個細胞轉錄差異產生的主要原因(參見細胞噪音英语cellular noise[1]。人們認爲,轉錄噪音的一個誘因爲轉錄暴增英语Transcriptional bursting[2][3][4],不過其他異質性誘因,比如細胞在有絲分裂過程中發生的不等分裂,也可能在相當程度上誘發了轉錄噪音[5]。暴增的轉錄,和轉錄簡單的概率模型不同,反映了不定期來回波動的基因活性的多樣狀態。這在細胞之間產生了蛋白質表達的差異。基因表達的噪音對細胞行爲有着巨大的影響,而且,這種噪音不是達到協調統一的狀態,就是逐漸減弱。在某些情況下,比如微生物要在多變的環境中生存,或者於幾種散分化中,這樣的變化是不可或缺的[6]。這樣的變化亦對臨床治療的效果產生影響,比如細菌可能因爲非遺傳學的原因對抗生素產生抗藥性[7]。基因表達的變化亦可增強癌細胞亞群對化療的抵抗力[8]

參考

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  6. ^ Losick, R.; Desplan, C. Stochasticity and cell fate. Science. 2008, 320 (5872): 65–68. Bibcode:2008Sci...320...65L. PMC 2605794 . PMID 18388284. doi:10.1126/science.1147888. 
  7. ^ Lewis, K. Persister Cells. Annual Review of Microbiology. 2010, 64: 357–372. PMID 20528688. doi:10.1146/annurev.micro.112408.134306. 
  8. ^ Sharma, S. V.; Lee, D. Y.; Li, B.; Quinlan, M. P.; Takahashi, F.; Maheswaran, S.; McDermott, U.; Azizian, N.; Zou, L.; Fischbach, M. A.; Wong, K. K.; Brandstetter, K.; Wittner, B.; Ramaswamy, S.; Classon, M.; Settleman, J. A chromatin-mediated reversible drug tolerant state in cancer cell subpopulations. Cell. 2010, 141 (1): 69–80. PMC 2851638 . PMID 20371346. doi:10.1016/j.cell.2010.02.027.