Kovaliski John, Sinclair Ron, Mutze Greg, Peacock David, Strive Tanja, Abrantes Joana, Esteves Pedro J, Holmes Edward C
NRM Biosecurity, Biosecurity South Australia, PO Box 1671, Adelaide, SA, 5001, Australia.
Invasive Animals Cooperative Research Centre, University of Canberra, Canberra, ACT, 2601, Australia.
Mol Ecol. 2014 Feb;23(2):408-20. doi: 10.1111/mec.12596. Epub 2013 Dec 9.
Rabbit Haemorrhagic Disease Virus (RHDV) was introduced into Australia in 1995 as a biological control agent against the wild European rabbit (Oryctolagus cuniculus). We evaluated its evolution over a 16-year period (1995-2011) by examining 50 isolates collected throughout Australia, as well as the original inoculum strains. Phylogenetic analysis of capsid protein VP60 sequences of the Australian isolates, compared with those sampled globally, revealed that they form a monophyletic group with the inoculum strains (CAPM V-351 and RHDV351INOC). Strikingly, despite more than 3000 rereleases of RHDV351INOC since 1995, only a single viral lineage has sustained its transmission in the long-term, indicative of a major competitive advantage. In addition, we find evidence for widespread viral gene flow, in which multiple lineages entered individual geographic locations, resulting in a marked turnover of viral lineages with time, as well as a continual increase in viral genetic diversity. The rate of RHDV evolution recorded in Australia -4.0 (3.3-4.7) × 10(-3) nucleotide substitutions per site per year - was higher than previously observed in RHDV, and evidence for adaptive evolution was obtained at two VP60 residues. Finally, more intensive study of a single rabbit population (Turretfield) in South Australia provided no evidence for viral persistence between outbreaks, with genetic diversity instead generated by continual strain importation.
兔出血症病毒（RHDV）于1995年被引入澳大利亚，作为一种针对野生欧洲兔（穴兔）的生物防治剂。我们通过检测在澳大利亚各地收集的50个分离株以及原始接种菌株，评估了其在16年期间（1995 - 2011年）的进化情况。将澳大利亚分离株的衣壳蛋白VP60序列与全球采样的序列进行系统发育分析，结果显示它们与接种菌株（CAPM V - 351和RHDV351INOC）形成一个单系群。令人惊讶的是，尽管自1995年以来RHDV351INOC已多次重新释放，但只有一个病毒谱系长期维持其传播，这表明其具有主要的竞争优势。此外，我们发现了广泛的病毒基因流动的证据，即多个谱系进入各个地理位置，导致病毒谱系随时间显著更替，以及病毒遗传多样性持续增加。在澳大利亚记录的RHDV进化速率为每年每个位点4.0（3.3 - 4.7）×10⁻³个核苷酸替换，高于之前在RHDV中观察到的速率，并且在两个VP60残基处获得了适应性进化的证据。最后对南澳大利亚的一个单一兔种群（Turretfield）进行的更深入研究没有发现病毒在疫情爆发之间持续存在的证据，相反，遗传多样性是由持续的毒株输入产生的。
