title: Life cycle of Blastocrithidia papi sp. n. (Kinetoplastea, Trypanosomatidae) in Pyrrhocoris apterus (Hemiptera, Pyrrhocoridae).
abstract: Blastocrithidia papi sp. n. is a cyst-forming trypanosomatid parasitizing firebugs (Pyrrhocoris apterus). It is a member of the Blastocrithidia clade and a very close relative of B. largi, to which it is almost identical through its SSU rRNA gene sequence. However, considering the SL RNA gene these two species represent quite distinct, not even related typing units. Morphological analysis of the new species revealed peculiar or even unique features, which may be useful for future taxonomic revision of the genus Blastocrithidia. These include a breach in the microtubular corset of rostrum at the site of contact with the flagellum, absence of desmosomes between flagellum and rostrum, large transparent vacuole near the flagellar pocket, and multiple vacuoles with fibrous content in the posterior portion of the cell. The study of the flagellates' behavior in the host intestine revealed that they may attach both to microvilli of enterocytes using swollen flagellar tip and to extracellular membranes layers using hemidesmosomes of flagellum. Laboratory experiments on B. papi transmission in P. apterus demonstrated that the parasite may be transmitted vertically (via contaminated surface of eggs) and horizontally (via contaminated substrate and/or necrophagy). We argue that the parasite exploits transmission mechanisms intended for obligate bacterial symbionts of P. apterus.
authors.affiliation: Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia.
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Frolov
authors.affiliation: Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia.
authors.forename: Marina N
authors.initials: MN
authors.lastname: Malysheva
authors.affiliation: Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia.
authors.forename: Anna I
authors.initials: AI
authors.lastname: Ganyukova
authors.affiliation: Life Science Research Centre, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czechia; Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 370 05 České Budejovice (Budweis), Czechia; Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czechia.
authors.forename: Vyacheslav
authors.initials: V
authors.lastname: Yurchenko
authors.affiliation: Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia; Life Science Research Centre, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czechia. Electronic address: aleksei.kostygov@osu.cz.
authors.forename: Alexei Y
authors.initials: AY
authors.lastname: Kostygov
mesh_terms: D000818:Animals; D020062:Heteroptera / Q000382:microbiology / Q000469:parasitology*; D007422:Intestines / Q000469:parasitology; D008018:Life Cycle Stages; D014351:Trypanosomatina / Q000145:classification / Q000166:cytology* / Q000502:physiology*
keywords: Cyst-forming trypanosomatids; Firebugs; Parasites; Transmission; Ultrastructure