Phylogeny of the House Dust Mites and Relatives: Evolution or Devolution of Parasitism?

本项目将利用现代系统学方法解释屋尘螨及其近缘种的起源和进化。这些螨属于Pyroglyphidae家族，是数百万人室内灰尘过敏的主要原因。Pyroglyphid螨属于一个更大的螨类，Psoroptidia，其中包括几乎完全寄生虫，永久生活在鸟类和哺乳动物的身体上。大多数研究者认为火螨科是许多寄生虫谱系的祖先，仅仅是因为这个科包括唯一的非寄生性psoroptidian物种，即生活在鸟类或哺乳动物巢穴中的屋尘螨及其亲属。 另一种假说认为，屋尘螨是从永久寄生的祖先进化而来的，这违反了进化论的真理，一旦寄生，就永远是寄生虫。 该研究的主要目的是确定寄生螨是否形成单一的进化谱系。从12个不同的线粒体和核基因的核苷酸序列数据，从至少140个物种代表了最高水平的多样性psoroptidians及其亲属将使用最新的技术进行分析。此外，一些新的物种已经和将在本研究中被发现。本项目还将为本科生、研究生和博士后学生提供系统学、分子生物遗传学和寄生虫学方面的培训。在过去两个供资周期中，有20多名本科生和6名博士生和博士后学生在PI的实验室接受了培训，其中一半以上是妇女，还有几名属于代表性不足的少数民族。该项目还提供了推广到年轻一代的鸟类学家和接触这些合作企业在寄生虫生物学。

This project will use modern systematic methods to explain the origin and evolution of the house dust mites and their relatives. These mites, in the family Pyroglyphidae, are the primary cause of house dust allergy in millions of people. Pyroglyphid mites belong to a larger group of mites, the Psoroptidia, which includes almost exclusively parasites, living permanently on the bodies of birds and mammals. Most workers regard the Pyroglyphidae as the ancestral group for many parasite lineages, simply because this family includes the only non-parasitic psoroptidian species, i.e. the house dust mites and their relatives living in bird or mammal nests. Another hypothesis suggests the house dust mites have evolved from permanently parasitic ancestors, violating the evolutionary truism once a parasite, always a parasite. The primary objective of the study is to determine whether the parasitic mites form a single evolutionary lineage. Nucleotide sequence data from 12 different mitochondrial and nuclear genes obtained from at least 140 species representing most of the higher level diversity of psoroptidians and their relatives will be analyzed using the latest techniques. Furthermore, a number of new species have been and will be discovered during this study. These will be described and a new classification of the Pyroglyphidae proposed.This project will also provide training in systematics, molecular phylogenetics and parasitology to undergraduate, graduate and post-doctoral students. Over 20 undergraduate students and six doctoral and postdoctoral students have been trained in the PI's lab over the course of the last two funding cycles, over half of them women and several belonging to underrepresented minorities. This project also provides outreach to a younger generation of ornithologists and exposure to these collaborative ventures in parasite biology.