title: Pankovaia semitubulata gen. et sp. n. (Microsporidia: Tuzetiidae) from nymphs of mayflies Cloeon dipterum L. (Insecta: Ephemeroptera) in Western Siberia.
abstract: The ultrastructure of a new microsporidian, Pankovaia semitubulata gen. et sp. n. (Microsporidia: Tuzetiidae), from the fat body of Cloeon dipterum (L.) (Ephemeroptera: Baetidae) is described. The species is monokaryotic throughout the life cycle, developing in direct contact with the host cell cytoplasm. Sporogonial plasmodium divides into 2-8 sporoblasts. Each sporoblast, then spore, is enclosed in an individual sporophorous vesicle. Fixed and stained spores of the type species P. semitubulata are 3.4 x 1.9microm in size. The polaroplast is bipartite (lamellar and vesicular). The polar filament is isofilar, possessing 6 coils in one row. The following features distinguish the genus Pankovaia from other monokaryotic genera of Tuzetiidae: (a) exospore is composed of multiple irregularly laid tubules with a lengthwise opening, referred to as "semitubules"; (b) episporontal space of sporophorous vesicle (SPV) is devoid of secretory formations; (c) SPV envelope is represented by a thin fragile membrane.
authors.affiliation: Research Institute of Biochemistry and Biophysics, Tomsk State University, Tomsk, Russia.
authors.forename: Anastasia V
authors.initials: AV
authors.lastname: Simakova
authors.forename: Yuri S
authors.initials: YS
authors.lastname: Tokarev
authors.forename: Irma V
authors.initials: IV
authors.lastname: Issi
mesh_terms: D000818:Animals; D005216:Fat Body / Q000382:microbiology; D006790:Host-Parasite Interactions; D007313:Insecta / Q000254:growth & development / Q000382:microbiology*; D008018:Life Cycle Stages; D046529:Microscopy, Electron, Transmission; D016814:Microsporidia / Q000145:classification* / Q000302:isolation & purification / Q000502:physiology / Q000648:ultrastructure; D009758:Nymph / Q000382:microbiology*; D012800:Siberia; D013045:Species Specificity; D013172:Spores, Fungal / Q000648:ultrastructure