Neovahlkampfia nana n. sp. Reinforcing an Underrepresented Subclade of Tetramitia, Heterolobosea

Abstract

The study provides robust genetic evidence that a newly isolated naked ameba with morphological and ultrastructural features indicative of Heterolobosea is a new species. Neovahlkampfia nana n. sp. associates with the yet underrepresented subclade of Tetramitia I. Considerable differences found in 18S rRNA gene sequences of individual molecular clones derived from DNA of five clonal cultures, using a low fidelity DNA polymerase, raised the issue of intragenomic sequence variation, a phenomenon that has not been previously studied in Heterolobosea. However, as proved using a higher fidelity DNA polymerase, the sequence variability observed was introduced by PCR mediated by the low fidelity polymerase and fixed by molecular cloning. This points to the potentially dubious validity of some current nominal species of Heterolobosea that differ from one another in just one or two base positions.

Dactylomonas gen. nov., a Novel Lineage of Heterolobosean Flagellates with Unique Ultrastructure, Closely Related to the Amoeba Selenaion koniopes Park, De Jonckheere & Simpson, 2012

“…; Park and Simpson ; Tyml et al. ; this study). Importantly, it appears only distantly related to Vahlkampfia , the type genus of Vahlkampfiidae.…”

“…The phylogenetic position of Selenaionida recovered using a single phylogenetic marker should be tested by multigene analyses in the future. The flagellate stage is unknown in the genus Neovahlkampfia (tetramitian clade I), which has been formally assigned into the nonmonophyletic family Vahlkampfiidae (Brown and de Jonckheere 1999); however, it represents a deep lineage of Tetramitia, branching between Selenaionida and Eutetramitia in the SSU rRNA gene trees (e.g., Kirby et al 2015;P anek et al 2017;Park and Simpson 2016;Tyml et al 2016; this study). Importantly, it appears only distantly related to Vahlkampfia, the type genus of Vahlkampfiidae.…”

“…However, one or the other of these stages has been lost or is unknown in a number of taxa. For example, members of Neovahlkampfia, Paravahlkampfia, Selenaion, and Vahlkampfia have only the amoeba stage, while species of Stephanopogon, Percolomonas, and Harpagon are flagellates without a known amoeba stage (e.g., Brown and de Jonckheere 1999;Fenchel and Patterson 1986;Page 1974;P anek et al 2012;Park et al 2012;Tyml et al 2016;Yubuki and Leander 2008). Heterolobosean amoebae are mostly cylindrical and move with eruptive lobopodia, except for the flattened amoeba of Pharyngomonas spp.…”

“…; Tyml et al. ; Yubuki and Leander ). Heterolobosean amoebae are mostly cylindrical and move with eruptive lobopodia, except for the flattened amoeba of Pharyngomonas spp.…”

A New Heterolobosean Amoeboflagellate, Tetramitus dokdoensis n. sp., Isolated from a Freshwater Pond on Dokdo Island in the East Sea, Korea

“…Five (18S rRNA gene) and four (ITS region) positive clones were partially sequenced, and a positive clone of each was completely sequenced using various sequencing primers. Although Taq DNA polymerase had a low error rate for a single-base substitution (8-10 9 10 À5 ) as described by the manufacturer's protocol, it could not be excluded the possibility that sequences variability might be infrequently induced by the original error for Taq DNA polymerase (Tyml et al 2017). The 18S rRNA gene and ITS region sequences from isolate MG4 have been deposited in the GenBank under accession numbers KY463322 and KY463323 respectively.…”