Storfer Andrew, Alfaro Michael E, Ridenhour Benjamin J, Jancovich James K, Mech Stephen G, Parris Matthew J, Collins James P
School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
Ecol Lett. 2007 Nov;10(11):1075-83. doi: 10.1111/j.1461-0248.2007.01102.x. Epub 2007 Sep 10.
Distinguishing whether pathogens are novel or endemic is critical for controlling emerging infectious diseases, an increasing threat to wildlife and human health. To test the endemic vs. novel pathogen hypothesis, we present a unique analysis of intraspecific host-pathogen phylogenetic concordance of tiger salamanders and an emerging Ranavirus throughout Western North America. There is significant non-concordance of host and virus gene trees, suggesting pathogen novelty. However, non-concordance has likely resulted from virus introductions by human movement of infected salamanders. When human-associated viral introductions are excluded, host and virus gene trees are identical, strongly supporting coevolution and endemism. A laboratory experiment showed an introduced virus strain is significantly more virulent than endemic strains, likely due to artificial selection for high virulence. Thus, our analysis of intraspecific phylogenetic concordance revealed that human introduction of viruses is the mechanism underlying tree non-concordance and possibly disease emergence via artificial selection.
区分病原体是新出现的还是地方性的，对于控制新出现的传染病至关重要，这些传染病对野生动物和人类健康构成的威胁与日俱增。为了验证地方性病原体与新出现病原体的假说，我们对北美西部虎螈和一种新出现的蛙病毒进行了独特的种内宿主-病原体系统发育一致性分析。宿主和病毒基因树存在显著的不一致性，表明病原体是新出现的。然而，这种不一致性可能是由于感染蝾螈的人类活动导致病毒传播造成的。排除与人类相关的病毒传播后，宿主和病毒基因树是相同的，这有力地支持了共同进化和地方性的观点。一项实验室实验表明，引入的病毒株比地方性病毒株的毒性显著更强，这可能是由于对高毒性进行人工选择的结果。因此，我们对种内系统发育一致性的分析表明，人类引入病毒是导致基因树不一致以及可能通过人工选择引发疾病的潜在机制。
