Heidinger Britt J, Slowinski Samuel P, Sirman Aubrey E, Kittilson Jeffrey, Gerlach Nicole M, Ketterson Ellen D
Biological Sciences Department, North Dakota State University, Fargo, ND, USA.
Department of Biology, Indiana University, Bloomington, IN, USA.
Mol Ecol. 2022 Dec;31(23):6216-6223. doi: 10.1111/mec.15819. Epub 2021 Feb 9.
Reproductive investment often comes at a cost to longevity, but the mechanisms that underlie these long-term effects are not well understood. In male vertebrates, elevated testosterone has been shown to increase reproductive success, but simultaneously to decrease survival. One factor that may contribute to or serve as a biomarker of these long-term effects of testosterone on longevity is telomeres, which are often positively related to lifespan and have been shown to shorten in response to reproduction. In this longitudinal study, we measured the effects of experimentally elevated testosterone on telomere shortening in free-living, male dark-eyed juncos (Junco hyemalis carolinensis), a system in which the experimental elevation of testosterone has previously been shown to increase reproductive success and reduce survival. We found a small, significant effect of testosterone treatment on telomeres, with testosterone-treated males exhibiting significantly greater telomere shortening with age than controls. These results are consistent with the hypothesis that increased telomere shortening may be a long-term cost of elevated testosterone exposure. As both testosterone and telomeres are conserved physiological mechanisms, our results suggest that their interaction may apply broadly to the long-term costs of reproduction in male vertebrates.
生殖投资往往以寿命为代价，但这些长期影响背后的机制尚未得到充分理解。在雄性脊椎动物中，已证明睾酮水平升高会提高繁殖成功率，但同时会降低存活率。端粒可能是导致睾酮对寿命产生这些长期影响的一个因素，或者可作为其生物标志物，端粒通常与寿命呈正相关，并且已证明会因繁殖而缩短。在这项纵向研究中，我们测量了实验性提高睾酮水平对自由生活的雄性暗眼灯草雀（Junco hyemalis carolinensis）端粒缩短的影响，在该系统中，先前已证明实验性提高睾酮水平会提高繁殖成功率并降低存活率。我们发现睾酮处理对端粒有微小但显著的影响，接受睾酮处理的雄性随着年龄增长端粒缩短程度明显大于对照组。这些结果与以下假设一致，即端粒缩短增加可能是睾酮暴露增加的长期代价。由于睾酮和端粒都是保守的生理机制，我们的结果表明它们之间的相互作用可能广泛适用于雄性脊椎动物繁殖的长期代价。
