Meeting Abstract
Reproductive investment often comes at a cost to longevity, and in male vertebrates, testosterone is expected to play a role in governing this trade-off. However, the mechanisms linking elevated testosterone exposure with reduced survival remain poorly understood. Telomeres, a mechanism of cellular and organismal aging, may be important in this context. We experimentally tested the hypothesis that exposure to elevated testosterone accelerates telomere loss in a free-living population of dark-eyed juncos (Junco hyemalis carolinensis). Previous research in this system has demonstrated that males with experimentally elevated testosterone sire more offspring, but have lower survival than controls. Here we measured telomere length and loss in known-age males that had received testosterone or control implants and found that males with experimentally elevated testosterone experienced significantly more telomere loss and tended to have shorter telomeres than controls. These results are consistent with the hypothesis that testosterone reduces longevity in part through its effects on telomeres. Given that both testosterone and telomeres are relatively conserved in vertebrates, this could be an important part of the mechanistic pathway underling the cost of reproduction.
