Werner Andreas, Berdal Ariane
Institute for Cell and Molecular Biosciences, University of Newcastle upon Tyne, Newcastle, United Kingdom.
Physiol Genomics. 2005 Oct 17;23(2):125-31. doi: 10.1152/physiolgenomics.00124.2005.
Antisense RNA was a rather uncommon term in a physiology environment until short interfering RNAs emerged as the tool of choice to knock down the expression of specific genes. As a consequence, the concept of RNA having regulatory potential became widely accepted. Yet, there is more to come. Computational studies suggest that between 15 and 25% of mammalian genes overlap, giving rise to pairs of sense and antisense RNAs. The resulting transcripts potentially interfere with each other's processing, thus representing examples of RNA-mediated gene regulation by endogenous, naturally occurring antisense transcripts. Concerns that the large-scale antisense transcription may represent transcriptional noise rather than a gene regulatory mechanism are strongly opposed by recent reports. A relatively small, well-defined group of antisense or noncoding transcripts is linked to monoallelic gene expression as observed in genomic imprinting, X chromosome inactivation, and clonal expression of B and T leukocytes. For the remaining, much larger group of bidirectionally transcribed genes, however, the physiological consequences of antisense transcription as well as the cellular mechanism(s) involved remain largely speculative.
在短干扰RNA成为敲低特定基因表达的首选工具之前，反义RNA在生理学环境中是一个相当不常见的术语。因此，RNA具有调控潜力的概念被广泛接受。然而，还有更多的情况。计算研究表明，15%至25%的哺乳动物基因相互重叠，产生了正义和反义RNA对。由此产生的转录本可能会相互干扰对方的加工过程，从而代表了由内源性、天然存在的反义转录本介导的RNA基因调控实例。近期报告强烈反对那种认为大规模反义转录可能代表转录噪声而非基因调控机制的观点。在基因组印记、X染色体失活以及B和T淋巴细胞的克隆表达中观察到，相对较小的、定义明确的一组反义或非编码转录本与单等位基因表达有关。然而，对于其余数量多得多的双向转录基因，反义转录的生理后果以及所涉及的细胞机制在很大程度上仍属推测。
