Parental effects on the larval performance of a tapeworm in its copepod first host

Parents can influence the phenotype of their offspring through various mechanisms, besides the direct effect of heredity. Such parental effects are little explored in parasitic organisms, perhaps because in many parasites per capita investment into offspring is low. I investigated whether parental identity, beyond direct genetic effects, could explain variation in the performance of the tapeworm Schistocephalus solidus in its first intermediate host, a copepod. I first determined that two breeding worms could be separated from one another after ~48 hrs of in vitro incubation and that the isolated worms continued producing outcrossed eggs, i.e. rates self-fertilization did not increase after separation. Thus, from a breeding pair, two sets of genetically comparable eggs can be collected that have unambiguous parental identities. In an infection experiment, I found that the development of larval worms tended to vary between the two parental worms within breeding pairs, but infection succe...

除遗传的直接效应外，亲代可通过多种机制影响后代的表型。这类亲代效应在寄生生物中研究较少，可能是因为许多寄生虫对后代的人均投入较低。我研究了除直接遗传效应外，亲代身份是否能解释裂头绦虫（Schistocephalus solidus）在其首个中间宿主——桡足类（copepod）中的表现差异。我首先确定，经过约48小时的体外培养后，一对繁殖的绦虫可彼此分离，且分离后的绦虫仍持续产生异交卵，即分离后自交率未升高。因此，从一对繁殖个体中可收集到两组遗传上可比且亲代身份明确的卵。在一项感染实验中，我发现繁殖对中两个亲代绦虫所产幼虫的发育存在差异趋势，但感染成功...