On being the right size: increased body size is associated with reduced telomere length under natural conditions

Abstract

Evolution of body size is likely to involve trade-offs between body size, growth rate and longevity. Within species, larger body size is associated with faster growth and ageing, and reduced longevity, but the cellular processes driving these relationships are poorly understood. One mechanism that might play a key role in determining optimal body size is the relationship between body size and telomere dynamics. However, we know little about how telomere length is affected when selection for larger size is imposed in natural populations. We report here on the relationship between structural body size and telomere length in wild house sparrows at the beginning and end of a selection regime for larger parent size that was imposed for 4 years in an isolated population of house sparrows. A negative relationship between fledgling size and telomere length was present at the start of the selection; this was extended when fledgling size increased under the selection regime, demonstrating a persistent covariance between structural size and telomere length. Changes in telomere dynamics, either as a correlated trait or a consequence of larger size, could reduce potential longevity and the consequent trade-offs could thereby play an important role in the evolution of optimal body size.

Corticosterone, inflammation, immune status and telomere length in frigatebird nestlings facing a severe herpesvirus infection

“…A possible explanation might lie with the fact that individuals with visible clinical signs of the disease were subjected to slower development in comparison to apparently healthy nestlings (field observation, Pineau K.). Indeed, previous studies have shown how telomeres might be shortened in individuals with faster development (Ringsby et al ., 2015). Thus, a lower metabolic rate attributable to slower growth might have masked any effects of infection on telomere erosion.…”

Brood size moderates associations between relative size, telomere length, and immune development in European starling nestlings

“…We predicted an interaction between brood size and relative nestling size in explaining the outcome variables, and the predicted interaction was indeed present for telomere length change and IL‐6. Thus, our results help reconcile previous experimental findings from jackdaws (Boonekamp et al., 2014) and starlings (Nettle et al., 2013) that the larger nestlings in large broods fare better than the smaller ones in terms of telomere attrition, with the negative associations between body size and telomere length observed in other field studies (Herborn et al., 2014; Noguera et al., 2015; Ringsby et al., 2015). These negative associations, in our data, are restricted to small broods, while positive associations appear in the largest broods.…”

“…Thus, other things being equal, there should be a trade‐off between body size at the end of the fledgling period and telomere length (Reichert et al., 2014). In accordance with this possibility, several recent avian studies have observed associations between larger body size or faster growth and shorter telomere length at the end of development (Herborn et al., 2014; Noguera, Metcalfe, Boner, & Monaghan, 2015; Ringsby et al., 2015). In addition, Ringsby et al.…”

“…In addition, Ringsby et al. (2015) showed, in house sparrows, that selection for increased body size led to a reduction in mean telomere length. The existence of a negative body size–telomere length relationship is consistent with the pattern often observed within populations that larger individuals tend to live less long (Bartke, 2012; Bernstein, 2010; Miller, Harper, Galecki, & Burke, 2002), given that shorter telomeres at the end of development are associated with reduced longevity (Boonekamp, Mulder, Salomons, Dijkstra, & Verhulst, 2014; Heidinger et al., 2012).…”

Evolutionary ecology of telomeres: a review

“…Ongoing selection on body size and corresponding selection in the wild on telomere length have been demonstrated in a (correlative) quantitative genetics field study of sand lizards (using TRF) . Similarly, artificial selection for shortened tarsus length (a measure of body size) in house sparrows ( Passer domesticus ) resulted in a correlated shortening of telomeres (using qPCR) …”