Siomi Mikiko C, Saito Kuniaki, Siomi Haruhiko
Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan.
FEBS Lett. 2008 Jul 23;582(17):2473-8. doi: 10.1016/j.febslet.2008.06.018. Epub 2008 Jun 20.
Transposable elements (TEs) are DNA elements found in the genomes of various organisms. TEs have been highly conserved during evolution, suggesting that they confer advantageous effects to their hosts. However, due to their ability to transpose into virtually any locus, TEs have the ability to generate deleterious mutations in the host genome. In response, a variety of different mechanisms have evolved to mitigate their activities. A main defense mechanism is RNA silencing, which is a gene silencing mechanism triggered by small RNAs. In this review, we address RNA silencing mechanisms that silence retrotransposons, a subset of TEs, and discuss how germline and somatic cells are equipped with different retrotransposon silencing mechanisms.
转座元件（TEs）是在各种生物体基因组中发现的DNA元件。TEs在进化过程中高度保守，这表明它们为宿主带来了有利影响。然而，由于它们能够转座到几乎任何位点，TEs有能力在宿主基因组中产生有害突变。作为回应，已经进化出了多种不同的机制来减轻它们的活性。一种主要的防御机制是RNA沉默，这是一种由小RNA触发的基因沉默机制。在这篇综述中，我们阐述了沉默逆转座子（TEs的一个子集）的RNA沉默机制，并讨论了生殖细胞和体细胞如何配备不同的逆转座子沉默机制。
