The long-lived queen: reproduction and longevity in female eusocial Damaraland mole-rats (Fukomys damarensis)

Abstract

The inverse relationship between reproduction and lifespan is one of the main concepts of life history theory. This association has been observed in most taxa, although exceptions have been found in which a breeding female outlives her non-reproductive cohorts. This relationship is well known in social insects, and it has recently come to light that reproductive females of certain social mole-rat species also exhibit extended lifespans relative to non-breeders. We analysed mark-recapture data over 13 years in 12 colonies of Damaraland mole-rats (Fukomys damarensis) to assess if colony queens lived longer than non-reproductive adult females. Queens were recaptured up to 8.5 years after initial capture (X = 6.2 years); significantly longer than non-reproductive females (X = 1.3 years), suggesting that a colony queen lives longer than her non-reproductive subordinates. This difference may be attributed to both physiological and social factors which may relax reproductive costs in queens.

Rank-Related Contrasts in Longevity Arise from Extra-Group Excursions Not Delayed Senescence in a Cooperative Mammal

“…elevated mortality. As increases in senescent cells are a major contributor to age-related declines in tissue function associated with an aging phenotype [24], our results suggest that dominants do not show delayed aging profiles, as has been suggested in some cooperatively breeding mammals [4][5][6]. Evidence of slower rates of telomere attrition in dominants would have been surprising given their greater investment in reproduction, which typically diverts resources away from self-maintenance and accelerates declines in physiological state with age [25].…”

“…In many cooperatively breeding animal societies, breeders outlive non-breeding subordinates, despite investing heavily in reproduction [1][2][3]. In eusocial insects, the extended lifespans of breeders arise from specialized slowed aging profiles [1], prompting suggestions that reproduction and dominance similarly defer aging in cooperatively breeding vertebrates, too [4][5][6]. Although lacking the permanent castes of eusocial insects, breeders of vertebrate societies could delay aging via phenotypic plasticity (similar rank-related changes occur in growth, neuroendocrinology, and behavior [7][8][9][10]), and such plastic deferment of aging may reveal novel targets for preventing aging-related diseases [11].…”

Long-lived rodents reveal signatures of positive selection in genes associated with lifespan and eusociality

“…Since non-reproductive individuals live shorter (and hence age faster) than their reproductive counterparts in Fukomys sp. 75-77 , these results are consistent with the oxidative stress theory of aging. The diverse signs of positive selection on branch 2 (NMR), 3 (LCA of all African molerats except NMR) and 7 (LCA of AMR and GMR) may suggest that the impact of oxidative stress on aging differs between NMR and other African mole-rats.…”

Reproduction, aging and mortality rate in social subterranean mole voles (Ellobius talpinus Pall.)

“…In laboratory-housed individuals, longevity does not differ between breeding and non-breeding naked mole-rats (Buffenstein 2005), but this is not the case for social African mole-rats of the Fukomys genera. In at least two species, F. anselli and F. mechowii, breeders live twice as long as non-breeders under both natural (Schmidt et al 2013) and laboratory (Dammann and Burda 2006;Dammann et al 2011) conditions. Therefore, this difference may be associated not only with a high rate of extrinsic mortality of non-breeders, but also with different patterns of intrinsic mortality.…”