TWO DIFFERENT SPECIES OFEUGLENA,E. GENICULATAANDE. MYXOCYLINDRACEA(EUGLENOPHYCEAE), ARE VIRTUALLY GENETICALLY AND MORPHOLOGICALLY IDENTICAL¹

Abstract

We investigated the similarity of a single Euglena myxocylindracea strain, isolated originally by Bold and MacEntee, to several Euglena geniculata strains on both morphological and DNA levels. We found the three DNA stretches, consisting of fragments coding for the parts of cytoplasmic and chloroplast small subunit rRNA, and the internal transcribed spacer (ITS2) of cytoplasmic rDNA, with the combined length of 4332 nucleotides, are identical in E. myxocylindracea and E. geniculata, strain SAG 1224‐4b. Morphological differences between E. myxocylindracea and any E. geniculata strain examined were well within the range of E. geniculata variability as well. The only difference behind the distinction of E. myxocylindracea from E. geniculata is the presence of the second chloroplast in the latter. However, we were able to induce the appearance of the second chloroplast in the cells of E. myxocylindracea and its disappearance in the cells of E. geniculata by changing the composition of the culture media. We therefore conclude that E. myxocylindracea Bold and MacEntee should be regarded as an environmental form of E. geniculata Dujardin. For the first time the morphology of E. geniculata chloroplasts was shown as revealed by confocal laser microscopy.

A new photosynthetic euglenoid isolated in Poland: Euglenaria clepsydroides sp. nov. (Euglenea)

“…DNA isolation, amplification and sequencing, and phylogenetic analysis Isolation of total DNA, amplification of nuclear SSU rDNA, and purification and sequencing of PCR product was performed by standard methods as previously described (Zakryś et al, 2002). The new sequence used in the present study has been deposited in GenBank as JQ691737.…”

“…The last 10 years have seen much taxonomic reclassification of these organisms, based on morphological and molecular data. As a result, the number of previously recognized species has been greatly reduced (Zakryś, 1997;Zakryś et al, 1997Zakryś et al, , 2002Zakryś et al, , 2004Shin & Triemer, 2004;Kosmala et al, 2005Kosmala et al, , 2007aKosmala et al, , 2007bKosmala et al, , 2009Karnkowska-Ishikawa et al, 2010, 2011, 2013 and some new species have been described based solely on molecular data (Kosmala et al, 2007a(Kosmala et al, , 2009. Among the green euglenoids, as is the case with many other groups of organisms, it has become increasingly difficult to find a new species that is clearly distinct morphologically.…”

Evolutionary Origin of Euglena

“…The first phylogenetic tree was based on nuclear small subunit (nSSU) rDNA sequences including only four species of euglenids (Montegut-Felkner and Triemer 1997). Later, the number of species used for phylogenetic analyses increased (Linton et al 1999(Linton et al , 2010Moreira et al 2001;Müllner et al 2001;Marin et al 2003;Nudelman et al 2003;Shin and Triemer 2004;Kosmala et al 2007a, b;Karnkowska-Ishikawa et al 2010Łukomska-Kowalczyk et al 2015) and other molecular markers were employed: internal transcribed spacer (ITS) (Zakryś et al 2004), nuclear large subunit (nLSU) rDNA (Brosnan et al 2003;Ciugulea et al 2008;Linton et al 2010;Kim et al 2012Kim et al , 2013Kim and Shin 2014), cytoplasmic small subunit (cpSSU rDNA) (Zakryś et al 2002;Milanowski et al 2001Milanowski et al , 2006Linton et al 2010), chloroplast LSU rDNA (Kim and Shin 2008;Kim et al 2015) and nuclear encoded protein coding sequences of hsp90 and psbO genes (Karnkowska et al 2015).…”

Genetic variability of Euglena agilis (Euglenophyceae)

“…Isolation of DNA, amplification, purification of PCR products and sequencing of chloroplast SSU and ITS2 rDNA was performed as previously described (Milanowski et al 2001;Zakry et al 2002). The GenBank accession numbers for SSU and ITS2 rDNA sequences reported in this paper are shown in Table 1.…”

“…and E. geniculata Duj. (Zakry et al 2002). Only in the last case the sequence analysis was used (16S, 18S, ITS2), while the two first dealt with analysis of fragment lengths (RAPD and RFLP).…”