title: Hyper-variable regions in 18S rDNA of Strongyloides spp. as markers for species-specific diagnosis.
abstract: Four hyper-variable regions (HVR-I to -IV) found in 18S ribosomal DNA sequences were compared among 34 isolates of 15 species of the genus Strongyloides to evaluate their diagnostic value. HVR-I to -III were short, and plural species exhibit the same nucleotide arrangement. Meanwhile, HVR-IV had 23 to 39 nucleotides, showing species-specific arrangements, except Strongyloides ransomi and Strongyloides venezuelensis, which had the same nucleotide sequence in HVR-IV but were readily distinguished by the difference in HVR-I and -III. Isolates of Strongyloides stercoralis from humans of USA, Japan, and Philippines, chimpanzees, and dogs had an identical sequence in this region. Meanwhile, intraspecific polymorphism in HVR-IV nucleotide arrangement was observed among isolates of Strongyloides fuelleborni and Strongyloides callosciureus, presumably reflecting process of geographical dispersal and adaptation to the hosts.
authors.affiliation: Department of Biology, Faculty of Medicine, and Institute of Scientific Research, Oita University, Hasama, Yufu, Oita 879-5593, Japan. hasegawa@med.oita-u.ac.jp
authors.forename: Hideo
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Shotaro
authors.initials: S
authors.lastname: Hayashida
authors.forename: Yatsukaho
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D018509:DNA, Helminth / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D004285:Dogs; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D051381:Rats; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013321:Strongyloides / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D013322:Strongyloidiasis / Q000175:diagnosis* / Q000469:parasitology
chemical_list: D018509:DNA, Helminth; D004275:DNA, Ribosomal; D005819:Genetic Markers; D012337:RNA, Ribosomal, 18S