title: Morphology and Molecular Phylogeny of Coelomic Gregarines (Apicomplexa) with Different Types of Motility: Urospora ovalis and U. travisiae from the Polychaete Travisia forbesii.
abstract: Urosporids (Apicomplexa: Urosporidae) are eugregarines that parasitise marine invertebrates, such as annelids, molluscs, nemerteans and echinoderms, inhabiting their coelom and intestine. Urosporids exhibit considerable morphological plasticity, which correlates with their different modes of motility and variations in structure of their cortical zone, according to the localisation within the host. The gregarines Urospora ovalis and U. travisiae from the marine polychaete Travisia forbesii were investigated with an emphasis on their general morphology and phylogenetic position. Solitary ovoid trophozoites and syzygies of U. ovalis were located free in the host coelom and showed metabolic activity, a non-progressive movement with periodic changes of the cell shape. Solitary trophozoites of U. travisiae, attached to the host tissue or free floating in the coelom, were V-shaped. Detached trophozoites demonstrated gliding motility, a progressive movement without observable cell body changes. In both gregarines, the cortex formed numerous epicytic folds, but superfolds appeared exclusively on the surface of U. ovalis during metabolic activity. SSU rDNA sequences obtained from U. ovalis and U. travisiae revealed that they belong to the Lecudinoidea clade; however, they are not affiliated with other coelomic urosporids (Pterospora spp. and Lithocystis spp.), but surprisingly with intestinal lecudinids (Difficilina spp.) parasitising nemerteans.
authors.affiliation: Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic. Electronic address: diakin@sci.muni.cz.
authors.forename: Andrei
authors.initials: A
authors.lastname: Diakin
authors.affiliation: Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaya emb. 7/9, Saint-Petersburg, 199 034, Russian Federation. Electronic address: gitapasker@yahoo.com.
authors.forename: Gita G
authors.initials: GG
authors.lastname: Paskerova
authors.affiliation: Department of Invertebrate Zoology, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow 119 234, Russian Federation.
authors.forename: Timur G
authors.initials: TG
authors.lastname: Simdyanov
authors.affiliation: Belozersky Institute for Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow 119 234, Russian Federation.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Aleoshin
authors.affiliation: Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic.
authors.forename: Andrea
authors.initials: A
authors.lastname: Valigurová
mesh_terms: D000818:Animals; D016782:Apicomplexa / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008124:Locomotion; D008853:Microscopy; D010802:Phylogeny; D011077:Polychaeta / Q000469:parasitology*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S
keywords: 18S rDNA phylogeny.; Urosporidae; gliding and metaboly; marine eugregarines; superfolds; ultrastructure