New explanation for the longevity of social insect reproductives: Transposable element activity

The increasing frailty that accompanies old age deeply influences our lives and permeates our thoughts. As a result, studies tackling this topic naturally fascinate both specialists and the general public. However, despite a wealth of research, the fundamental mechanisms of aging remain undetermined. Damage to molecules, such as DNA and proteins that are essential for life and proper organismal function, is a prime candidate for explaining the degeneration that accompanies aging (1). Much of the research into age-related DNA damage has focused on the damage caused by oxidative stress (2), but this is by no means the only potential source of disruption that can occur to DNA. A ground-breaking study in PNAS by Elsner et al. (3) leverages the remarkable natural differences in longevity found among termite castes to identify transposable element (TE) activity as a potential source of DNA damage that is elevated in older workers compared with the reproductive kings and queens.TEs are genetic elements capable of moving around the genome and inserting themselves into new locations (4). These insertions can cause significant damage when they interrupt crucial sequences of DNA, such as protein coding sequences or regulatory regions, and are thus associated with mutation-based diseases, such as cancer (5). Because of these deleterious effects, the expression of TEs (which is required for their transposition) is usually suppressed by the cell machinery. However, this suppression is not complete (6) and TE activity increases with age, leading to an accumulation of TE-related damage in a range of species (6⇓–8).While much research on aging focuses on humans and other mammals, important breakthroughs have come … [↵][1]1To whom correspondence may be addressed. Email: eric.lucas{at}lstmed.ac.uk or Laurent.Keller{at}unil.ch. [1]: #xref-corresp-1-1