Centro de Investigación en Biodiversidad y Conservación, Universidad Autónoma del Estado de Morelos Avenida Universidad 1001, Chamilpa, 62209 Cuernavaca, Morelos, Mexico.
Division de Ciencias Naturales y Exacatas, Departamento de Biología, Universidad de Guanajuato, Lascuráin de Retana 5, Col. Centro C.P. 36000 Guanajuato, Guanajuato, Mexico.
J Exp Biol. 2019 Mar 8;222(Pt 5):jeb194530. doi: 10.1242/jeb.194530.
In invertebrates, it has recently been reported that secondary sexual characteristics (SSCs) reflect the antioxidant defense of their bearers, but it is not known what physiological link maintains the honesty of those signals. Here, we used the damselfly to test whether juvenile hormone plays such a role. First, we analyzed whether oxidative damage is a real threat in natural damselfly populations by examining the accumulation of oxidized guanines as a function of age in males. Then, we injected paraquat (a pro-oxidant agent) and added the juvenile hormone analog methoprene (JHa) to the experimental group and the JHa vehicle (acetone) to the control group, to determine whether JHa increases the levels of pro-oxidants and antioxidants. We found that DNA oxidation increased with age, and that levels of hydrogen peroxide and superoxide dismutase, but not catalase or glutathione, were elevated in the JHa group compared with the control group. We propose that juvenile hormone is a mediator of the relationship between SSCs and antioxidant capacity and, based on the literature, we know that JHa suppresses the immune response. We therefore suggest that juvenile hormone is a molecular mediator of the general health of males, which is reflected in their SSCs.
在无脊椎动物中，最近有报道称第二性征（SSC）反映了其携带者的抗氧化防御能力，但尚不清楚是什么生理联系维持了这些信号的真实性。在这里，我们使用蜻蜓来测试保幼激素是否发挥了这种作用。首先，我们通过分析雄性个体中随年龄增长而积累的氧化鸟嘌呤，来检验氧化损伤是否是自然状态下蜻蜓种群的真实威胁。然后，我们向实验组注射百草枯（一种促氧化剂）和保幼激素类似物烯虫酯（JHa），向对照组注射 JHa 溶剂（丙酮），以确定 JHa 是否会增加氧化剂和抗氧化剂的水平。结果发现，DNA 氧化随年龄增长而增加，与对照组相比，实验组的过氧化氢和超氧化物歧化酶水平升高，但过氧化氢酶和谷胱甘肽水平没有升高。我们提出，保幼激素是 SSC 和抗氧化能力之间关系的中介物，并且根据文献，我们知道 JHa 会抑制免疫反应。因此，我们认为保幼激素是雄性一般健康状况的分子中介物，这反映在他们的 SSC 上。
