Introduced cryptic species of parasites exhibit different invasion pathways
Introduced cryptic species of parasites exhibit different invasion pathways
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DOI：
10.1073/pnas.0609603103
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发表时间：
2006-12-26
影响因子：
11.1
通讯作者：
Chiba, Satoshi
中科院分区：
文献类型：
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作者：
Miura, Osamu;Torchin, Mark E.;Chiba, Satoshi
有时传染性病原体侵入并在新的地理区域定居。另一些可能被引入，但由于在新地区缺乏合适的宿主而从未建立。这种现象对于许多具有复杂生命周期的寄生虫尤其如此，其中不同的生命阶段需要不同的宿主物种。通过人类介导的入侵，世界生物群的同质化可能会使宿主和寄生虫团聚，导致疾病在新的地区爆发。在这里，我们使用分子遗传学来区分入侵途径的两个digenean吸虫寄生虫和他们的异国情调的主机，亚洲泥螺，Batillaria attramentaria。在北美引入的种群中发现的所有蜗牛单倍型与在日本地区常见的单倍型相同，这些地区为北美的养殖提供了牡蛎，支持了蜗牛是从日本引进的种子牡蛎的假设。两个神秘的吸虫物种被引入到北美人口的高频率。我们发现，这些物种之一的遗传变异显着减少，这表明它经历了一个瓶颈或创始人事件的主机蜗牛。相比之下，其他寄生虫物种中没有遗传变异。我们假设这种寄生虫过去和现在都是由候鸟自然传播的，只有在宿主蜗牛B之后才能建立。attramentaria，被引入北美。评估入侵途径的性质和入侵后的后果将有助于减轻人类，牲畜和野生动物在日益全球化的世界中传播疾病。
Sometimes infectious agents invade and become established in new geographic regions. Others may be introduced yet never become established because of the absence of suitable hosts in the new region. This phenomenon may be particularly true for the many parasites with complex life cycles, where various life stages require different host species. Homogenization of the world's biota through human-mediated invasions may reunite hosts and parasites, resulting in disease outbreaks in novel regions. Here we use molecular genetics to differentiate invasion pathways for two digenean trematode parasites and their exotic host, the Asian mud snail, Batillaria attramentaria. All of the snail haplotypes found in introduced populations in North America were identical to haplotypes common in the areas of Japan that provided oysters for cultivation in North America, supporting the hypothesis that the snails were introduced from Japan with seed oysters. Two cryptic trematode species were introduced to North American populations in high frequencies. We found a marked reduction of genetic variation in one of these species, suggesting it experienced a bottleneck or founder event comparable to that of the host snail. In contrast, no genetic variation was lost in the other parasite species. We hypothesize that this parasite was and is dispersed naturally by migratory shorebirds and was able to establish only after the host snail, B. attramentaria, was introduced to North America. Evaluation of the nature of invasion pathways and postinvasion consequences will aid mitigation of spreading diseases of humans, livestock, and wildlife in an increasingly globalized world.