PDF(Pubmed)
Abstract：
Gastrointestinal nematodes (GIN) use flexible life history strategies to maintain their fitness under environmental challenges. Costs incurred by a challenge to one life trait can be recouped by increasing the expression of subsequent life traits throughout their life cycle. Anticipating how parasites respond to the challenge of control interventions is critical for the long-term sustainability of the practice and to further ensure that the parasites withstand favourable adaptive responses. There is currently limited information on whether distinct populations of a GIN species respond to the same environmental challenge in a consistent manner, with similar alterations to their life history strategies or comparable fitness outcomes. This study compared the life history traits and experimental fitness of three distinct Haemonchus contortus isolates exposed to environmental challenges at both the parasitic (i.e., passage through resistant or susceptible sheep) and free-living (i.e., exposure to diverse climatic conditions) life stages. The key findings show that H. contortus maintain their fitness under challenge with isolate-specific alterations to their life history strategies. Further, partial exploration of the H. contortus isolates transcriptomes using cDNA-AFLP methods confirmed disparate expression profiles between them. These results bring fresh insights into our understanding of the non-genetic adaptive processes of GIN that may hinder the efficacy of parasite control strategies.
摘要：
胃肠道线虫（GIN）使用灵活的生活史策略来维持其在环境挑战下的适应性。挑战一种生命特征所产生的成本可以通过在其整个生命周期中增加后续生命特征的表达来弥补。预测寄生虫如何应对控制干预的挑战对于实践的长期可持续性至关重要，并进一步确保寄生虫承受有利的适应性反应。目前关于GIN物种的不同种群是否以一致的方式应对相同的环境挑战的信息有限，他们的生活史策略或类似的健身结果也有类似的改变。这项研究比较了三种不同的hemonchuscontortus分离株的生活史特征和实验适应性，这些分离株暴露于两种寄生虫的环境挑战（即，通过抗性或易感绵羊)和自由生活(即，暴露于不同的气候条件)生命阶段。关键发现表明，H.contortus在挑战下通过对其生活史策略进行隔离特异性改变来维持其适应性。Further,使用cDNA-AFLP方法对H.contortus分离株转录组的部分探索证实了它们之间不同的表达谱。这些结果为我们对GIN的非遗传适应性过程的理解带来了新的见解，这可能会阻碍寄生虫控制策略的功效。
