Fellous S, Koella J C
Division of Biology, Imperial College London, Ascot, UK.
J Evol Biol. 2009 Mar;22(3):582-8. doi: 10.1111/j.1420-9101.2008.01665.x. Epub 2009 Jan 29.
We investigated whether a parasite with two routes of transmission responds to the different transmission opportunities offered by male and female hosts by using different transmission strategies in the two sexes. The parasite Ascogregarina culicis, which infects the mosquito Aedes aegypti, can be transmitted as its host's pupa transforms into an adult or when a female lays its eggs. As the latter transmission route is missing in males, we expected, and found, that the parasite releases a greater proportion of its infectious forms during emergence when it is within a male than when it infects a female. The transmission route, which influences the parasite's dispersal and the evolution of its virulence, was also affected by the dose of infection and the parasite's previous transmission route. Our results emphasize the complexity underlying the development of parasites and show their ability to tune their strategy to their environment.
我们研究了一种具有两种传播途径的寄生虫是否会通过在两性中采用不同的传播策略来应对雄性和雌性宿主提供的不同传播机会。感染埃及伊蚊的库蚊阿氏单孢子虫，可在其宿主蛹变为成虫时传播，也可在雌蚊产卵时传播。由于雄性不存在后一种传播途径，我们预期并发现，当寄生虫在雄性宿主体内羽化时，其释放的感染性形态比例要高于感染雌性宿主时。影响寄生虫传播及其毒力进化的传播途径，也受到感染剂量和寄生虫先前传播途径的影响。我们的研究结果强调了寄生虫发育背后的复杂性，并表明它们有能力根据环境调整其策略。
