Data from: Disentangling the aging network of a termite queen

Background: Most insects are relatively short-lived, with a maximum
lifespan of a few weeks, like the aging model organism, the fruit-fly
Drosophila melanogaster. By contrast, the queens of many social insects
(termites, ants and some bees) can live from a few years to decades. This
makes social insects promising models in aging research providing insights
into how a long reproductive life can be achieved. Yet, aging studies on
social insect reproductives are hampered by a lack of quantitative data on
age-dependent survival and time series analyses that cover the whole
lifespan of such long-lived individuals. We studied aging in queens of the
drywood termite Cryptotermes secundus by determining survival
probabilities over a period of 15 years and performed transcriptome
analyses for queens of known age that covered their whole lifespan.
Results: The maximum lifespan of C. secundus queens was 13 years, with a
median maximum longevity of 11.0 years. Time course and co-expression
network analyses of gene expression patterns over time indicated a
non-gradual aging pattern. It was characterized by networks of genes that
became differentially expressed only late in life, namely after ten years,
which associates well with the median maximum lifespan for queens. These
old-age gene networks reflect processes of physiological upheaval. We
detected strong signs of stress, decline, defense and repair at the
transcriptional level of epigenetic control as well as at the
post-transcriptional level with changes in transposable element activity
and the proteostasis network. The latter depicts an upregulation of
protein degradation, together with protein synthesis and protein folding,
processes which are often down-regulated in old animals. The simultaneous
upregulation of protein synthesis and autophagy is indicative of a
stress-response mediated by the transcription factor cnc, a homolog of
human nrf genes. Conclusion: Our results show non-linear senescence with a
rather sudden physiological upheaval at old-age. Most importantly, they
point to a re-wiring in the proteostasis network and stress as part of the
aging process of social insect queens, shortly before queens die.