title: Genetic structure of Ascaris roundworm in Japan and patterns of its geographical variation.
abstract: Ascaris roundworm isolates from Japan and central Europe were examined by  sequencing analyses to better understand geographically induced nucleotide variation and genotype  distribution according to host. Three well-supported clusters (denoted as A, B, C) were identified  by generating cox1 sequences of mtDNA from these regions. Among 5 pig isolates collected in  eastern Honshu, Japan, in 2010, 3 carried DNA characteristics for cluster A and 2 corresponded  with the characteristics of cluster B. The sequence of the human isolate JH1 from north-central  Honshu, fixed in formalin since 1972, conformed to the characteristics of cluster A. Differential  analysis of ribosomal ITS1 region revealed the JH1 isolate sequence profile of Ascaris  lumbricoides. Cluster C, which was the most distinguish cluster, was formed by reference Slovak  isolates and has been so far found almost exclusively in European pigs. A fluctuating prevailing  distribution of A and B lineages in human and pig hosts in different territories of the world and  the global distribution of several haplotypes indicate their establishment before secondary  differentiation in a given region due to host affiliation. The protocol established for DNA  isolation from formalin-fixed specimens using the modified procedure with the Qiagen extraction  set can be used as a tool for retrospective studies in ascarid helminths when only archival  specimens are available.
authors.affiliation: Parasitological Institute, Slovak Academy of Sciences, Košice, Slovakia. snabel＠saske.sk
authors.forename: Viliam
authors.initials: V
authors.lastname: Snábel
authors.forename: Kensuke
authors.initials: K
authors.lastname: Taira
authors.forename: Serena
authors.initials: S
authors.lastname: Cavallero
authors.forename: Stefano
authors.initials: S
authors.lastname: D'Amelio
authors.forename: Petra
authors.initials: P
authors.lastname: Rudohradská
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Saitoh
mesh_terms: D000818:Animals; D017164:Ascaris lumbricoides / Q000235:genetics* / Q000302:isolation & purification*; D016000:Cluster Analysis; D051545:Cyclooxygenase 1 / Q000235:genetics; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005060:Europe; D014644:Genetic Variation; D006801:Humans; D007564:Japan; D024101:Mitochondrial Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D058974:Phylogeography; D017422:Sequence Analysis, DNA; D013552:Swine
chemical_list: D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer; D024101:Mitochondrial Proteins; D051545:Cyclooxygenase 1