Host association drives genetic divergence in the bed bug, Cimex lectularius
Host association drives genetic divergence in the bed bug, Cimex lectularius
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DOI：
10.1111/mec.13086
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发表时间：
2015-03-01
影响因子：
4.9
通讯作者：
Schal, Coby
中科院分区：
文献类型：
--
作者：
Booth, Warren;Balvin, Ondrej;Schal, Coby
由于与替代宿主的长期关联（即宿主相关分化），一个物种的同域种群中可能存在遗传分化。虽然在几种植食性昆虫中已经记录了与宿主相关的分化，但在动物寄生虫中已知的情况要少得多。臭虫 Cimex lectularius 是一种无翅昆虫，代表了一种潜在的模式生物，可用于阐明活动性相对有限的动物寄生虫中与宿主相关的分化过程。随着现代人类从非洲扩展到欧亚大陆，据推测，臭虫将其宿主范围从蝙蝠扩大到了整个欧亚大陆共享洞穴住所的人类。与人类相关的 C.lectularius 分布在世界各地，而与蝙蝠相关的 C.lectularius 则遍布欧洲各地，通常出现在人造建筑中。我们使用 mtDNA、微卫星位点和敲低抗性基因变体评估了与每个宿主相关的收集群体内部和群体之间的遗传结构和基因流。核和线粒体数据都支持宿主特定群体之间缺乏显着的当代基因流动。在某些地区，与人类相关的臭虫种群表现出有限的遗传多样性和较高的近交水平，这可能是由于人类介导的移动、每次侵扰很少发生额外的引入事件以及害虫控制。相比之下，蝙蝠栖息地内的种群表现出较高的遗传多样性和较低的相关性水平，这表明种群稳定，但由于宿主扩散和昆虫死亡率而存在时间波动。与之前发表的形态和行为分化的证据相一致，这里提供的遗传数据表明 C.lectularius 目前正在通过宿主关联经历谱系分歧。
Genetic differentiation may exist among sympatric populations of a species due to long-term associations with alternative hosts (i.e. host-associated differentiation). While host-associated differentiation has been documented in several phytophagus insects, there are far fewer cases known in animal parasites. The bed bug, Cimex lectularius, a wingless insect, represents a potential model organism for elucidating the processes involved in host-associated differentiation in animal parasites with relatively limited mobility. In conjunction with the expansion of modern humans from Africa into Eurasia, it has been speculated that bed bugs extended their host range from bats to humans in their shared cave domiciles throughout Eurasia. C.lectularius that associate with humans have a cosmopolitan distribution, whereas those associated with bats occur across Europe, often in human-built structures. We assessed genetic structure and gene flow within and among populations collected in association with each host using mtDNA, microsatellite loci and knock-down resistance gene variants. Both nuclear and mitochondrial data support a lack of significant contemporary gene flow between host-specific populations. Within locations human-associated bed bug populations exhibit limited genetic diversity and elevated levels of inbreeding, likely due to human-mediated movement, infrequent additional introduction events per infestation, and pest control. In contrast, populations within bat roosts exhibit higher genetic diversity and lower levels of relatedness, suggesting populations are stable with temporal fluctuations due to host dispersal and bug mortality. In concert with previously published evidence of morphological and behavioural differentiation, the genetic data presented here suggest C.lectularius is currently undergoing lineage divergence through host association.