Assortative pairing by telomere length in King Penguins (Aptenodytes patagonicus) and relationships with breeding success

Abstract

13Telomeres are non-coding genetic repeats protecting the ends of linear chromosomes. Long 14 telomeres are often associated with high individual survival, and inter-individual variation in 15 telomere length has recently been proposed as a proxy for individual quality. Therefore, one 16 might expect individuals of either sex with long telomeres to be of higher intrinsic quality and 17 to be preferred in the context of mate choice. Thus, in sexually monomorphic species where 18 individuals discriminate mates on the basis of signals of intrinsic quality, mate choice should 19 lead to assortative pairing by telomere length, and it should be associated with breeding 20 performance. We tested these two predictions in the king penguin (Aptenodytes patagonicus, 21 Miller, 1778), a sexually monomorphic seabird. Over 3 years of study and 73 penguin pairs 22 under contrasting environmental conditions, we found strong assortative pairing by telomere 23 length. Interestingly, only female telomere length was positively associated to chick survival 24 up to fledging, and this relationship was only apparent when foraging conditions at sea were 25 average. The positive link between telomere length and breeding success confirmed that 26 telomere length is somehow related to individual biological state at a given time. The 27 proximate mechanisms by which birds assess individual state related to telomere length 28 remains to be discovered. 29 30

No sex differences in adult telomere length across vertebrates: a meta-analysis

“…See electronic supplementary material, Methods and Results for further information. species study g variance sample size tissue method BIRDS Acrocephalus arundinaceus [ 29 ] −0.086 0.059 68 RBC qPCR Acrocephalus sechellensis [ 30 ] 0.174 0.005 837 RBC qPCR Aptenodytes patagonicus [ 31 ] 0.115 0.08 50 RBC qPCR Aptenodytes patagonicus [ 32 ] −0.158 0.038 106 RBC qPCR Aptenodytes patagonicus [ 33 ] −0.094 0.027 146 RBC qPCR Branta leucopsis [ 34 ] 0.678 0.141 34 RBC TRFS Calidris alpina [ 35 ] −0.177 …”

Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins

“…King penguin relative telomere length (RTL) was measured using a protocol specifically developed and routinely used on king penguins (Geiger et al., 2012; Le Vaillant et al., 2015; Reichert et al., 2015; Schull et al., 2018; Stier et al., 2014). DNA was extracted from nucleated red blood cells (Nucleospin Blood QuickPure, Macherey‐Nagel) and checked for quality using gel‐migration and a NanoDrop 1000 (Thermo Scientific) spectrophotometer (absorbance ratio A 260/280 ; A 260/230 ).…”

Does Reproduction Shorten Telomeres? Towards Integrating Individual Quality with Life‐History Strategies in Telomere Biology

“…Consequently, if telomeres are biomarkers of reproductive output, the selective pressures acting on them could be sex dependent, which has indeed been shown . Some studies reported significant effects only in one sex, whereas others ignored one sex (males) completely . Discussing sex differences should also attract more attention because in some populations males and females display divergent telomere erosion patterns and losing telomeres may bring about sex‐specific consequences.…”