Klimov Pavel B, Oconnor Barry M
Museum of Zoology, University of Michigan, 1109 Geddes Avenue, Ann Arbor, MI 48109-1079, USA.
Mol Phylogenet Evol. 2008 Jun;47(3):1135-56. doi: 10.1016/j.ympev.2007.12.025. Epub 2008 Jan 17.
Phylogenic relationships of the Psoroptidia, a group of primarily parasitic mites of vertebrates, were investigated based on sequences from three nuclear genes (4.2 kb aligned) sampled from 126 taxa. Several morphological classification schemes and a recent molecular analysis, suggesting that the group may not be monophyletic were statistically rejected by newly generated molecular data, and the results are robust under a range of analytical and partition strategies. Six families Psoroptidae, Lobalgidae (mammalian parasites), Pyroglyphidae (house dust mites and parasites inside feather calamus), Turbinoptidae (upper respiratory track parasites of birds), Psoroptoididae (downy feather mites), and Epidermoptidae (skin parasites of birds) form a well-supported monophyletic group (the epidermoptid-psoroptid complex). These relationships, recovered by combined and separate analyses of all gene partitions, were previously suspected based on some morphological evidence, but evidence has been dismissed as resulting from convergence based on similar parasitic ecologies. The existence of the epidermoptid-psoroptid complex and the statistical rejection of Sarcoptoidea (the morphology-based group joining all mammal-associated mites) indicate that current classification criteria, influenced as they are by host preferences, need to be reassessed for non-pterolichoid superfamilies. However, two of our findings remain sensitive to analytical methods and assumptions: (i) the families Heterocoptidae and Hypoderatidae as the first and second closest outgroups of Psoroptidia, respectively, and (ii) the superfamily Pterolichoidea (including Freyanoidea) forming a sister clade to the remaining psoroptidian superfamilies. Our findings suggest that (i) house dust mites (Pyroglyphidae: Dermatophagoidinae) originated from a parasitic ancestor within the core of Psoroptidia, violating a basic principle of evolution that it is virtually impossible for a permanent parasite to become free-living, and (ii) there were at least two shifts from presumably avian to mammalian hosts.
基于从126个分类单元中采样的三个核基因序列（比对后为4.2 kb），对主要寄生于脊椎动物的疥螨目（Psoroptidia）的系统发育关系进行了研究。几种形态学分类方案以及最近的一项分子分析表明该类群可能并非单系群，但新生成的分子数据在统计学上否定了这些方案，并且在一系列分析和划分策略下，结果都是可靠的。疥螨科（Psoroptidae）、洛氏螨科（Lobalgidae，寄生于哺乳动物）、尘螨科（Pyroglyphidae，屋尘螨及羽轴内寄生虫）、鼻甲螨科（Turbinoptidae，鸟类上呼吸道寄生虫）、类疥螨科（Psoroptoididae，绒羽螨）和表皮螨科（Epidermoptidae，鸟类皮肤寄生虫）这六个科构成了一个得到充分支持的单系群（表皮螨 - 疥螨复合体）。通过对所有基因分区进行联合分析和单独分析得出的这些关系，此前曾基于一些形态学证据被怀疑过，但这些证据因类似寄生生态导致的趋同现象而被摒弃。表皮螨 - 疥螨复合体的存在以及对肉螨总科（Sarcoptoidea，基于形态学将所有与哺乳动物相关的螨归为一类）的统计学否定表明，当前受宿主偏好影响的分类标准需要针对非翼螨总科进行重新评估。然而，我们的两项发现对分析方法和假设仍然敏感：（i）异爪螨科（Heterocoptidae）和皮下螨科（Hypoderatidae）分别作为疥螨目的第一和第二近缘外类群，以及（ii）翼螨总科（Pterolichoidea，包括弗氏螨总科 Freyanoidea）形成了其余疥螨目总科的姐妹分支。我们的研究结果表明：（i）屋尘螨（尘螨科：尘螨亚科Dermatophagoidinae）起源于疥螨目核心类群中的寄生祖先，这违背了进化的一个基本原则，即永久寄生虫几乎不可能转变为自由生活的生物；（ii）至少有两次从推测的鸟类宿主向哺乳动物宿主的转变。
