The genomes of virtually all organisms contain repetitive sequences that are generated by the activity of transposable elements (transposons). Transposons are mobile genetic elements that can move from one genomic location to another; in this process, they amplify and increase their presence in genomes, sometimes to very high copy numbers. In this Review we discuss new evidence and ideas that the activity of retrotransposons, a major subgroup of transposons overall, influences and even promotes the process of ageing and age-related diseases in complex metazoan organisms, including humans. Retrotransposons have been coevolving with their host genomes since the dawn of life. This relationship has been largely competitive, and transposons have earned epithets such as ‘junk DNA’ and ‘molecular parasites’. Much of our knowledge of the evolution of retrotransposons reflects their activity in the germline and is evident from genome sequence data. Recent research has provided a wealth of information on the activity of retrotransposons in somatic tissues during an individual lifespan, the molecular mechanisms that underlie this activity, and the manner in which these processes intersect with our own physiology, health and well-being.

几乎所有生物的基因组都包含由转座因子（转座子）的活动产生的重复序列。转座子是可移动的遗传元件，可以从一个基因组位置移动到另一个位置；在这个过程中，它们放大并增加了它们在基因组中的存在，有时会达到非常高的拷贝数。在这篇综述中，我们讨论了新的证据和想法，即反转录转座子的活性是转座子的一个主要亚群，它影响甚至促进复杂后生动物生物体（包括人类）的衰老过程和与年龄相关的疾病。自生命诞生以来，反转录转座子就一直与其宿主基因组共同进化。这种关系在很大程度上是竞争性的，转座子赢得了诸如“垃圾 DNA”和“分子寄生虫”之类的绰号。我们对反转录转座子进化的大部分了解反映了它们在种系中的活性，并且从基因组序列数据中可以明显看出。最近的研究提供了大量信息，涉及个体生命周期中体细胞组织中反转录转座子的活动、这种活动背后的分子机制，以及这些过程与我们自身的生理、健康和福祉相交的方式。