Korkofigas Evan, Park Tracey, Sparkes Timothy C
Department of Biological Sciences, DePaul University, 2325 North Clifton Avenue, Chicago, IL, 60614, USA.
Nanosphere Inc., 4088 Commercial Avenue, Northbrook, IL, 60062, USA.
Parasitol Res. 2016 Jan;115(1):339-45. doi: 10.1007/s00436-015-4753-z. Epub 2015 Oct 1.
The acanthocephalan parasite Acanthocephalus dirus infects the freshwater isopod Caecidotea intermedius as an intermediate host before completing its life cycle in a fish. Transmission to the definitive host occurs after the parasite has reached the cystacanth stage, and development into this stage is associated with changes in several behavioral and physiological traits of the host. Given the potential importance of host energy availability to trait modification, we examined the relationship between cystacanth-stage infection and energy storage of adult isopods. Six samples of infected and uninfected male C. intermedius were collected from a population in March, April, and May during which time cystacanth-stage A. dirus dominate infections and modification of behavior and physiology occurs in nature. Biochemical assays revealed that infected male C. intermedius contained more glycogen and more lipid than uninfected males and that this difference was present throughout the sampling period, which represents the entire adult phase of the host's life. Additional analysis revealed that infected and uninfected males differed in their pattern of allocation to each energy source and that host lipid levels were negatively correlated with parasite intensity. We propose that the typical pattern of allocation and storage of host energy appears to be disrupted by A. dirus infection and that the changes are more likely to favor the parasite than the host.
棘头虫寄生虫直棘棘头虫在鱼类体内完成其生命周期之前，将淡水等足类中间宿主中间凯西多蒂虫作为中间宿主进行感染。在寄生虫达到囊尾蚴阶段后，会传播到终末宿主，而发育到这个阶段与宿主的一些行为和生理特征的变化有关。鉴于宿主能量供应对特征改变的潜在重要性，我们研究了囊尾蚴阶段感染与成年等足类动物能量储存之间的关系。在3月、4月和5月从一个种群中采集了六组受感染和未受感染的雄性中间凯西多蒂虫样本，在此期间，囊尾蚴阶段的直棘棘头虫在感染中占主导地位，并且在自然环境中会发生行为和生理的改变。生化分析表明，受感染的雄性中间凯西多蒂虫比未受感染的雄性含有更多的糖原和脂质，并且这种差异在整个采样期间都存在，而采样期代表了宿主生命的整个成年阶段。进一步分析表明，受感染和未受感染的雄性在每种能量来源的分配模式上存在差异，并且宿主脂质水平与寄生虫强度呈负相关。我们认为，宿主能量分配和储存的典型模式似乎因直棘棘头虫感染而受到干扰，并且这些变化更有可能有利于寄生虫而非宿主。
