Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland.
Bioessays. 2011 Nov;33(11):810-7. doi: 10.1002/bies.201100045. Epub 2011 Aug 22.
Planctomycetes, Verrucomicrobia and Chlamydia are prokaryotic phyla, sometimes grouped together as the PVC superphylum of eubacteria. Some PVC species possess interesting attributes, in particular, internal membranes that superficially resemble eukaryotic endomembranes. Some biologists now claim that PVC bacteria are nucleus-bearing prokaryotes and are considered evolutionary intermediates in the transition from prokaryote to eukaryote. PVC prokaryotes do not possess a nucleus and are not intermediates in the prokaryote-to-eukaryote transition. Here we summarise the evidence that shows why all of the PVC traits that are currently cited as evidence for aspiring eukaryoticity are either analogous (the result of convergent evolution), not homologous, to eukaryotic traits; or else they are the result of horizontal gene transfers.
厚壁菌门、疣微菌门和衣原体是原核生物的门，有时被归为真细菌的 PVC 超门。一些 PVC 物种具有有趣的特征，特别是内部膜表面类似于真核生物的内膜。一些生物学家现在声称，PVC 细菌是带核的原核生物，被认为是从原核生物到真核生物过渡的进化中间体。PVC 原核生物没有细胞核，也不是原核生物到真核生物过渡的中间体。在这里，我们总结了证据，表明为什么目前被引用为有抱负的真核生物的所有 PVC 特征要么是类似的（趋同进化的结果），与真核生物特征没有同源性；要么是水平基因转移的结果。
