title: Comparison of the morphology of oocysts and the phylogenetic analysis of four Ascogregarina species (Eugregarinidae: Lecudinidae) as inferred from small subunit ribosomal DNA sequences.
abstract: This study on the ultrastructure of the oocysts of four isolated species of Ascogregarina (A. taiwanensis (Lien and Levine) (Eugregarinidae: Lecudinidae) from Aedes albopictus (Skuse), A. culicis (Ross) (Eugregarinidae: Lecudinidae) from Aedes aegypti (L.), A. armigerei (Eugregarinidae: Lecudinidae) from Armigeres subalbatus (Coquillet), and Ascogregarina sp. (Eugregarinidae: Lecudinidae) from Ochlerotatus japonicus japonicus (Theobald)) using a scanning electron microscope revealed significant differences in size and in surface structure. The average length of the oocyst was greatest in A. armigerei (13.2+/-0.2 microm) (mean+/-SD) and least in A. culicis (8.8+/-0.4 microm). Oocysts were of moderate length in A. taiwanensis (9.9+/-0.6 microm) and in Ascogregarina sp. (10.7+/-1.1 microm) isolated from O. j. japonicus. The ultrastructure of the surface of the A. culicis oocyst was rough in texture with numerous dense spots and was easily distinguishable from the oocysts of the other three Ascogregarina spp. The maximum likelihood tree inferred from small subunit ribosomal DNA (SSU rDNA) sequences indicated that the four Ascogregarina spp. form a monophyletic cluster among other gregarine parasites. Within the Ascogregarina clade, A. culicis, A. taiwanensis, and Ascogregarina sp. from O. j. japonicus showed a close relationship, whereas A. armigerei was a distantly related species.
authors.affiliation: Department of Medical Entomology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan. rcsudipta@yahoo.com
authors.forename: Sudipta
authors.initials: S
authors.lastname: Roychoudhury
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Isawa
authors.forename: Keita
authors.initials: K
authors.lastname: Hoshino
authors.forename: Toshinori
authors.initials: T
authors.lastname: Sasaki
authors.forename: Noriko
authors.initials: N
authors.lastname: Saito
authors.forename: Kyoko
authors.initials: K
authors.lastname: Sawabe
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D000330:Aedes / Q000469:parasitology; D000818:Animals; D016782:Apicomplexa / Q000145:classification* / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D001483:Base Sequence; D009033:Culicidae / Q000469:parasitology*; D016054:DNA, Protozoan / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D033661:Oocysts / Q000648:ultrastructure*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal