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Molecular systematics of marine gregarine apicomplexans from Pacific tunicates, with descriptions of five novel species of Lankesteria

Authors :
Kevin C. Wakeman
Sonja Rueckert
Brian S. Leander
Holger Jenke-Kodama
Source :
International Journal of Systematic and Evolutionary Microbiology. 65:2598-2614
Publication Year :
2015
Publisher :
Microbiology Society, 2015.

Abstract

The eugregarines are a group of apicomplexan parasites that mostly infect the intestines of invertebrates. The high level of morphological variation found within and among species of eugregarines makes it difficult to find consistent and reliable traits that unite even closely related lineages. Based mostly on traits observed with light microscopy, the majority of described eugregarines from marine invertebrates has been classified into a single group, the Lecudinidae. Our understanding of the overall diversity and phylogenetic relationships of lecudinids is very poor, mainly because only a modest amount of exploratory research has been done on the group and very few species of lecudinids have been characterized at the molecular phylogenetic level. In an attempt to understand the diversity of marine gregarines better, we surveyed lecudinids that infect the intestines of Pacific ascidians (i.e. sea squirts) using ultrastructural and molecular phylogenetic approaches; currently, these species fall within one genus,Lankesteria. We collected lecudinid gregarines from six ascidian host species, and our data demonstrated that each host was infected by a different species ofLankesteria: (i)Lankesteria hesperidiiformissp. nov., isolated fromDistaplia occidentalis, (ii)Lankesteria metandrocarpaesp. nov., isolated fromMetandrocarpa taylori, (iii)Lankesteria halocynthiaesp. nov., isolated fromHalocynthia aurantium, (iv)Lankesteria herdmaniaesp. nov., isolated fromHerdmania momus, (v)Lankesteriacf.ritterellae, isolated fromRitterella rubra, and (vi)Lankesteria didemnisp. nov., isolated fromDidemnum vexillum. Visualization of the trophozoites with scanning electron microscopy showed that four of these species were covered with epicytic folds, whereas two of the species were covered with a dense pattern of epicytic knobs. The molecular phylogenetic data suggested that species ofLankesteriawith surface knobs form a clade that is nested within a paraphyletic assemblage species ofLankesteriawith epicytic folds.

Details

ISSN :
14665034 and 14665026
Volume :
65
Database :
OpenAIRE
Journal :
International Journal of Systematic and Evolutionary Microbiology
Accession number :
edsair.doi.dedup.....c1a38d1dff6b69da1f5cfa8401fabeef