Seasonal shifts in the insect gut microbiome are concurrent with changes in cold tolerance and immunity
Seasonal shifts in the insect gut microbiome are concurrent with changes in cold tolerance and immunity
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DOI：
10.1111/1365-2435.13153
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发表时间：
2018-10-01
影响因子：
5.2
通讯作者：
Sinclair, Brent J.
中科院分区：
文献类型：
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作者：
Ferguson, Laura V.;Dhakal, Pranav;Sinclair, Brent J.
1.环境的季节性变化，如温度的变化，有可能改变昆虫等外温类动物与其微生物群之间的功能关系。我们的目标是确定：(A)温度的季节性变化是否改变昆虫肠道微生物组的组成，以及(B)微生物组的变化是否伴随着宿主生理的变化，包括免疫系统和对寒冷的反应。我们将春季田野蟋蟀(Gryllus Veletis)的实验室种群暴露在实验室微宇宙和含有土壤和树叶的田野微宇宙中，模拟越冬条件。在夏、秋、冬、春四个季节，从蟋蟀肠道中提取16S细菌基因组DNA并测序，以捕捉微生物群落组成的季节变化。肠道微生物群的组成在小宇宙之间相似，总体上高度厌氧。在这两个微观世界中，我们捕捉到了微生物群落组成的相似的季节变化，越冬导致了这些微生物群落的永久性变化。特别是假单胞菌的丰度。和沃尔巴克氏菌属(Wolbachia spp.)越冬期间增加。在肠道微生物群发生越冬变化的同时，绒毛棉获得了耐寒能力，免疫功能暂时发生变化，在春季恢复到夏季的活动水平。在特定的方式下，血细胞浓度在冬季增加，但真菌感染的存活率下降，而清除血淋巴中细菌的能力保持不变。总体而言，我们证明肠道微生物群确实会随季节变化，并与其他生理变化相一致。我们假设这些变化可能是相互关联的，并建议接下来重要的是确定微生物群中的这些变化是否有助于寄主越冬的成功。
1. Seasonal changes in the environment, such as varying temperature, have the potential to change the functional relationship between ectothermic animals, such as insects, and their microbiomes. Our objectives were to determine: (a) whether seasonal changes in temperature shift the composition of the insect gut microbiome, and (b) whether changes in the microbiome are concomitant with changes in the physiology of the host, including the immune system and response to cold.2. We exposed laboratory populations of the spring field cricket, Gryllus veletis (Orthoptera: Gryllidae), to simulated overwintering conditions in both a laboratory microcosm and a field-like microcosm containing soil and leaves. In summer, autumn, winter and spring, we extracted and sequenced 16S bacterial genomic DNA from cricket guts, to capture seasonal variation in the composition of the microbiome.3. The composition of the gut microbiome was similar between microcosms, and overall highly anaerobic. In both microcosms, we captured similar seasonal variation in the composition of the microbiome, where overwintering resulted in permanent changes to these microbial communities. In particular, the abundance of Pseudomonas spp. decreased, and that of Wolbachia spp. increased, during overwintering.4. Concurrent with overwintering changes in the gut microbiome, G.veletis acquire freeze tolerance and immune function shifts temporarily, returning to summer levels of activity in the spring. In a specific manner, haemocyte concentrations increase but survival of fungal infection decreases in the winter, whereas the ability to clear bacteria from the haemolymph remains unchanged.5. Overall, we demonstrate that the gut microbiome does shift seasonally, and in concert with other physiological changes. We hypothesize that these changes may be linked, and suggest that it will next be important to determine whether these changes in the microbiome contribute to host overwintering success.