ABSTRACT

Understanding how context (e.g., host species, environmental conditions) drives disease susceptibility is an essential goal of disease ecology. We hypothesized that in bat white-nose syndrome (WNS), species-specific host–pathogen interactions may partly explain varying disease outcomes among host species. We characterized bat and pathogen transcriptomes in paired samples of lesion-positive and lesion-negative wing tissue from bats infected with Pseudogymnoascus destructans in three parallel experiments. The first two experiments analyzed samples collected from the susceptible Nearctic Myotis lucifugus and the less-susceptible Nearctic Eptesicus fuscus, following experimental infection and hibernation in captivity under controlled conditions. The third experiment applied the same analyses to paired samples from infected, free-ranging Myotis myotis, a less susceptible, Palearctic species, following natural infection and hibernation (n = 8 sample pairs/species). Gene expression by P. destructans was similar among the three host species despite varying environmental conditions among the three experiments and was similar within each host species between saprophytic contexts (superficial growth on wings) and pathogenic contexts (growth in lesions on the same wings). In contrast, we observed qualitative variation in host response: M. lucifugus and M. myotis exhibited systemic responses to infection, while E. fuscus up-regulated a remarkably localized response. Our results suggest potential phylogenetic determinants of response to WNS and can inform further studies of context-dependent host–pathogen interactions.

摘要

了解环境（例如宿主物种、环境条件）如何驱动疾病易感性是疾病生态学的一个基本目标。我们假设，在蝙蝠白鼻综合症（WNS）中，物种特异性的宿主-病原体相互作用可能部分解释了宿主物种之间不同的疾病结果。我们在三个平行实验中对感染假裸子囊菌的蝙蝠的病变阳性和病变阴性翅膀组织的配对样本中的蝙蝠和病原体转录组进行了表征。前两个实验分析了在受控条件下进行实验性感染和圈养冬眠后，从易感近北极鼠耳蝠和较不易感的近北极浅色鼠耳蝠中收集的样本。第三个实验对自然感染和冬眠后受感染的自由放养鼠耳蝠（一种较不易受影响的古北物种）的配对样本进行了相同的分析（n = 8 个样本对/物种）。尽管三个实验中的环境条件不同，但三个宿主物种中破坏性腐殖质的基因表达相似，并且每个宿主物种内腐生环境（翅膀上的表面生长）和致病环境（同一翅膀上的病变生长）之间的基因表达相似。相反，我们观察到宿主反应的质变：M. lucifugus和M. myotis表现出对感染的全身反应，而E. fuscus上调了显着的局部反应。我们的结果表明了 WNS 反应的潜在系统发育决定因素，并且可以为背景依赖性宿主-病原体相互作用的进一步研究提供信息。