School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.
Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW 2522, Australia.
J Exp Biol. 2021 May 1;224(9). doi: 10.1242/jeb.242164. Epub 2021 May 5.
Alternative reproductive tactics (ARTs) are correlated suites of sexually selected traits that are likely to impose differential physiological costs on different individuals. While moderate activity might be beneficial, animals living in the wild often work at the margins of their resources and performance limits. Individuals using ARTs may have divergent capacities for activity. When pushed beyond their respective capacities, they may experience condition loss, oxidative stress, and molecular damage that must be repaired with limited resources. We used the Australian painted dragon lizard that exhibits color polymorphism as a model to experimentally test the effect of exercise on body condition, growth, reactive oxygen species (ROS) and telomere dynamics - a potential marker of stress and aging and a correlate of longevity. For most males, ROS levels tended to be lower with greater exercise; however, males with yellow throat patches - or bibs - had higher ROS levels than non-bibbed males. At the highest level of exercise, bibbed males exhibited telomere loss, while non-bibbed males gained telomere length; the opposite pattern was observed in the no-exercise controls. Growth was positively related to food intake but negatively correlated with telomere length at the end of the experiment. Body condition was not related to food intake but was positively correlated with increases in telomere length. These results, along with our previous work, suggest that aggressive - territory holding - bibbed males suffer physiological costs that may reduce longevity compared with non-bibbed males with superior postcopulatory traits.
替代生殖策略（ARTs）是一系列相关的性选择特征，这些特征可能会给不同的个体带来不同的生理成本。适度的活动可能是有益的，但生活在野外的动物经常在资源和性能极限的边缘工作。使用 ART 的个体可能具有不同的活动能力。当它们超过各自的能力时，它们可能会经历条件损失、氧化应激和分子损伤，这些必须在有限的资源下进行修复。我们使用澳大利亚彩绘石龙子作为模型，对运动对身体状况、生长、活性氧（ROS）和端粒动力学的影响进行了实验测试，端粒动力学是应激和衰老的潜在标志物，也是长寿的相关指标。对于大多数雄性来说，运动越多，ROS 水平越低；然而，有黄色喉斑的雄性（或 bibs）比没有 bibs 的雄性具有更高的 ROS 水平。在最高水平的运动下，bibs 雄性表现出端粒丢失，而 non-bibs 雄性则获得了端粒长度；在没有运动的对照组中则观察到相反的模式。生长与食物摄入量呈正相关，但与实验结束时的端粒长度呈负相关。身体状况与食物摄入量无关，但与端粒长度的增加呈正相关。这些结果，以及我们之前的工作表明，与具有优越的交配后特征的非 bibs 雄性相比，具有攻击性的雄性（即持有领地的雄性 bibs）可能会承受生理成本，从而降低其寿命。
