A molecular perspective on the genera Paragonimus Braun, Euparagonimus Chen and Pagumogonimus Chen

Abstract

The status of the genera Euparagonimus Chen, 1963 and Pagumogonimus Chen, 1963 relative to Paragonimus Braun, 1899 was investigated using DNA sequences from the mitochondrial cytochrome c oxidase subunit I (CO1) gene (partial) and the nuclear ribosomal DNA second internal transcribed spacer (ITS2). In the phylogenetic trees constructed, the genus Pagumogonimus is clearly not monophyletic and therefore not a natural taxon. Indeed, the type species of Pagumogonimus,P. skrjabini from China, is very closely related to Paragonimusmiyazakii from Japan. The status of Euparagonimus is less obvious. Euparagonimus cenocopiosus lies distant from other lungflukes included in the analysis. It can be placed as sister to Paragonimus in some analyses and falls within the genus in others. A recently published morphological study placed E. cenocopiosus within the genus Paragonimus and probably this is where it should remain.

PCR-based determination of internal transcribed spacer (ITS) regions of ribosomal DNA of giant intestinal fluke, Fasciolopsis buski (Lankester, 1857) Looss, 1899

“…The taxonomy of F. buski has been based mainly on morphological data complemented with ecological, cytological, and pathological results as well as clinical manifestations. PCR-based techniques utilizing the ITS sequences have proven to be a reliable tool to identify the various lung fluke species and their phylogenetic relationships (Blair et al 1999;Iwagami et al 2000). In respect of F. buski, the 18S rRNA sequence is known (Blair and Barker 1993, accession number L06668) but the sequences from ITS markers are not described so far.…”

“…and of Fascioloides magna from different geographical regions have been discriminated on the basis of ITS sequences (Adlard et al 1993). Studies on phylogeny and/or intraspecific variations in Paragonimus species have recently been done using second ITS (ITS2) sequences (Blair et al 1997(Blair et al , 1999Iwagami et al 2000). The usefulness of the ITS2 region for species discrimination has also been demonstrated in nematodes, for example, Strongylus, Trichostrongylus species, larvae of Dictyocaulus viviparus and D. eckerti (Campbell et al 1994;Hoste et al 1995;Samson-Himmelstjerna et al 1997).…”

Morphological differences and molecular similarities between Paragonimus bangkokensis and P. harinasutai

“…In addition, all ITS2 and CO1 sequences of P. bangkokensis and P. harinasutai available by now (16 December 2008) from the DNA database were downloaded and used for phylogenetic analyses. Since close genetic relationships between Paragonimus ohirai and P. bangkokensis as well as P. harinasutai were observed by several studies (Blair et al 1999b;Le et al 2006;Doanh et al 2007aDoanh et al , 2008, all ITS2 and CO1 sequences of P. ohirai (including its synonyms: Paragonimus sadoensis and Paragonimus iloktsuenensis, see Blair et al 1997) were also downloaded and used for phylogenetic analyses. For the out-groups, we used three Paragonimus species, Paragonimus vietnamensis, Paragonimus heterotremus, and Paragonimus proliferus (Doanh et al 2007a(Doanh et al , b, 2008.…”

Ancient divergence of Paragonimus westermani in Sri Lanka

“…4.0 beta (Swofford 2002). Previously reported (Blair et al 1997(Blair et al , 1999bIwagami et al 2000) ribosomal ITS2 and mitochondrial partial CO1 nucleotide sequences of other species of Paragonimus were used for the phylogenetic analysis (Table 1). The sequences of ITS2 and CO1 were combined and used as one data set.…”