Anava Sarit, Posner Rachel, Rechavi Oded
Department of Neurobiology; Wise Faculty of Life Sciences & Sagol School of Neuroscience; Tel Aviv University ; Tel Aviv, Israel.
Worm. 2015 Jan 28;3(4):e989798. doi: 10.4161/21624054.2014.989798. eCollection 2014 Oct-Dec.
Caenorhabditis elegans (C. elegans) nematodes transmit small RNAs across generations, a process that enables transgenerational regulation of genes. In contrast to changes to the DNA sequence, transgenerational transmission of small RNA-mediated responses is reversible, and thus enables "soft" or "flexible" inheritance of acquired characteristics. Until very recently only introduction of foreign genetic material (viruses, transposons, transgenes) was shown to directly lead to inheritance of small RNAs. New discoveries however, demonstrate that starvation also triggers inheritance of endogenous small RNAs in C.elegans. Multiple generations of worms inherit starvation-responsive endogenous small RNAs, and starvation also results in heritable extension of the progeny's lifespan. In this Commentary paper we explore the intriguing possibility that large parts of the genome and many additional traits are similarly subjected to heritable small RNA-mediated regulation, and focus on the potential influence of transgenerational RNAi on the worm's physiology. While the universal relevance of this mechanism remains to be discovered, we will examine how the discoveries made in worms already challenge long held dogmas in genetics and evolution.
秀丽隐杆线虫能将小RNA跨代传递，这一过程实现了基因的跨代调控。与DNA序列的变化不同，小RNA介导的反应的跨代传递是可逆的，因此能够实现获得性特征的“软”或“灵活”遗传。直到最近，只有引入外来遗传物质（病毒、转座子、转基因）才被证明会直接导致小RNA的遗传。然而，新的发现表明，饥饿也会触发秀丽隐杆线虫内源性小RNA的遗传。多代线虫会遗传对饥饿有反应的内源性小RNA，饥饿还会导致后代寿命的可遗传延长。在这篇评论文章中，我们探讨了一个有趣的可能性，即基因组的很大一部分以及许多其他性状同样受到可遗传的小RNA介导的调控，并关注跨代RNA干扰对蠕虫生理学的潜在影响。虽然这一机制的普遍相关性仍有待发现，但我们将研究在蠕虫中取得的发现如何已经挑战了遗传学和进化领域长期以来的教条。
