Phylogeny of the reptilian Eimeria: are Choleoeimeria and Acroeimeria valid generic names?

Abstract

2015). Phylogeny of the reptilian Eimeria: are Choleoeimeria and Acroeimeria valid generic names?. -Zoologica Scripta, 44, 684-692.Reptiles are the animals with the most described coccidian species among all vertebrates. However, the co-evolutionary relationships in this host-parasite system have been scarcely studied. Paperna & Landsberg (South African Journal of Zoology, 24, 1989, 345) proposed the independent evolutionary origin of the Eimeria-like species isolated from reptiles based on morphological and developmental characteristics of their oocysts. Accordingly, they suggested the reclassification of these parasites in two new genera, Choleoeimeria and Acroeimeria. The validity of the genera proposed to classify reptilian Eimeria species remained unresolved due to the lack of species genetically characterized. In this study, we included 18S rRNA gene sequences from seven Eimeria-like species isolated from five different lizard host families. The phylogenetic analyses confirmed the independent evolutionary origin of the Eimeria-like species infecting lizards. Within this group, most species were placed into two monophyletic clades. One of them included the species with ellipsoidal oocysts (i.e. Choleoeimeria-like oocysts), whereas the species with more spheroidal oocysts (i.e. Acroeimeria-like oocysts) were included in the second one. This result supports the taxonomic validity of the genera Acroeimeria and Choleoeimeria.

Mitochondrial genomes of Australian chicken Eimeria support the presence of ten species with low genetic diversity among strains

“…A comparison of the mtDNA amino acid Eimeria phylogeny to those constructed using ribosomal DNA 18S sequences (Chapman et al, 2013;Megía-Palma et al, 2015) shows general systematic congruence between the genomes. The genus Caryospora has a basal position in the phylogeny, the rabbit infecting species group together and the avian infecting Isospora sp.…”

“…In addition Caryospora bigenetica, Cyclospora cayetanensis and an avian Isospora sp. were included as these species have been reported paraphyletic with some representatives nested within the Eimeria clade (Barta et al, 2012;Chapman et al, 2013;Megía-Palma et al, 2015) . A representative of the genus Choleoeimeria was used to root the phylogeny.…”

“…Initial trees were rooted with an avian Isospora sp., however, a genetic distance matrix suggested this species might also be nested within the Eimeria genus so a more distant taxa, Choleoeimeria sp., was selected to root the amino acid phylogeny. The DNA sequence of this genus was clearly divergent (amino acid sequences were alignable but large tracts of non-coding DNA could not be aligned) to all other species in the analysis and a ribosomal DNA phylogeny placed Choleoeimeria basal to the greater Eimeria clade (Megía-Palma et al, 2015). Single representatives of each ingroup species were analysed to avoid bias.…”

Two new species of coccidia (Apicomplexa: Eimeriidae) from leaf-tailed geckos, Uroplatus spp. (Sauria: Gekkonidae) from Madagascar, including a new host of Eimeria brygooi Upton & Barnard, 1987

“…However, in spite of seeing sporocysts in E. schneideri without a Stieda body and oöcysts with a L/W ratio ranging from 1.1–1.4 (sensu Paperna and Landsberg, 1989), we believe it prudent at this time to place our new species in the genus Eimeria rather than in Acroeimeria (sensu Paperna and Landsberg, 1989) for two valid reasons: (1) lack of tissue samples showing endogenous stages invested in a displaced host-cell border on the surface of the intestinal mucosal epithelium and/or (2) distinct DNA sequences that separate Eimeria spp. from this genus (Megía-Palma et al, 2015). …”

“… ** Could be Choleoeimeria ; for discussion, see Megía-Palma et al (2015), who suggests those oöcysts possessing an oöcyst shape index (OSI = L/W ratio) >1.4 and undergoing endogenous development in the gall bladder are Choleoeimeria spp. …”