Thermal sensitivity of the Spiroplasma-Drosophila hydei protective symbiosis: The best of climes, the worst of climes
Thermal sensitivity of the Spiroplasma-Drosophila hydei protective symbiosis: The best of climes, the worst of climes
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DOI：
10.1111/mec.15799
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发表时间：
2021-01-24
影响因子：
4.9
通讯作者：
Hurst, Gregory D. D.
中科院分区：
文献类型：
--
作者：
Corbin, Chris;Jones, Jordan E.;Hurst, Gregory D. D.
昆虫天敌攻击的结果通常受到宿主体内保护性共生体的影响。然而，在自然种群中保护功能的程度将取决于表型的稳健性和共生关系对非生物环境中的变化。我们研究了一个关键的环境参数的影响-温度-的共生体螺原体对其宿主果蝇hydei的保护作用的效力，对攻击的寄生蜂Leptopilina heterotoma。此外，我们调查了共生体的垂直传输，这可能是一个关键的决定因素的共生体的持续能力的温度敏感性。我们发现，垂直传播比以前认为的更强大，螺原体被维持在25摄氏度，18摄氏度和18/15摄氏度的昼夜周期，分离损失率只在15摄氏度增加。在共生体传输丧失之前，对黄蜂攻击的保护被消融，共生体在18摄氏度时未能拯救苍蝇宿主。我们的结论是，在自然种群中的保护性共生的存在不能简单地推断出存在的共生体的保护能力已在狭窄的控制条件下进行了测试。更广泛地说，我们认为热环境可能是自然环境中防御性共生体进化生态学的重要决定因素，可能会驱动共生体频率的季节性、纬度和海拔变化。
The outcome of natural enemy attack in insects is commonly influenced by the presence of protective symbionts in the host. The degree to which protection functions in natural populations, however, will depend on the robustness of the phenotype and symbiosis to variation in the abiotic environment. We studied the impact of a key environmental parameter-temperature-on the efficacy of the protective effect of the symbiont Spiroplasma on its host Drosophila hydei, against attack by the parasitoid wasp Leptopilina heterotoma. In addition, we investigated the thermal sensitivity of the symbiont's vertical transmission, which may be a key determinant of the ability of the symbiont to persist. We found that vertical transmission was more robust than previously considered, with Spiroplasma being maintained at 25 degrees C, at 18 degrees C and with 18/15 degrees C diurnal cycles, with rates of segregational loss only increasing at 15 degrees C. Protection against wasp attack was ablated before symbiont transmission was lost, with the symbiont failing to rescue the fly host at 18 degrees C. We conclude that the presence of a protective symbiosis in natural populations cannot be simply inferred from the presence of a symbiont whose protective capacity has been tested under narrow controlled conditions. More broadly, we argue that the thermal environment is likely to represent an important determinant of the evolutionary ecology of defensive symbioses in natural environments, potentially driving seasonal, latitudinal and altitudinal variation in symbiont frequency.