Allobodo chlorophagus n. gen. n. sp., a Kinetoplastid that Infiltrates and Feeds on the Invasive Alga Codium fragile

Publication date: Available online 1 August 2018Source: ProtistAuthor(s): Joshua D. Goodwin, Thomas F. Lee, Paul Kugrens, Alastair G.B. SimpsonA novel biflagellate protist that consumed chloroplasts inside material of the invasive marine green alga Codium fragile was reported from the U.S. east coast in 2003. We observed a similar association in C. fragile from five sites in Nova Scotia, Canada during 2013 and 2014. After incubating Codium fragments for 2-3 days, some utricles and filaments contained numerous chloroplast-consuming cells. Transmission electron microscopy (TEM) confirmed that these were kinetoplastids with a pankinetoplast, large electron-dense droplets in the cytoplasm and a connective between the paraxonemal rod bases, but no conspicuous para-cytopharyngeal rod, all consistent with U.S. material observed in 2003. The ITS1-5.8S rRNA-ITS2 sequences from 13 Nova Scotia isolates were identical. SSU rRNA gene phylogenies placed the Codium-associated kinetoplastid in neobodonid clade ‘1E’. Clade 1E likely contains no previously described species, and branches outside all other major neobodonid groups, either as their sister or as a separate lineage, depending on rooting. These results indicate that the kinetoplastid represents a single species that merits a new genus (and family), and we describe it as Allobodo chlorophagus n. gen., n. sp. The lack of evidence for food sources other than Codium is consistent with a parasitic association, but other possibilities...
Source: Protist - Category: Molecular Biology Source Type: research