title: Occurrence of spermic diploid and aspermic triploid forms of Fasciola in Vietnam and their molecular characterization based on nuclear and mitochondrial DNA.
abstract: Fasciola spp. found in Asian countries are diversified in nature, and they should therefore be characterized by spermatogenesis, ploidy and genetic differentiation as well as morphology. The present study showed that spermic diploid and aspermic triploid forms of Fasciola occurred in Vietnam. The spermic diploid specimens were accurately identified as F. gigantica, while the aspermic triploids could not be identified on the basis of their morphology by the ratio of body length and width and DNA sequences of nuclear ribosomal ITS1 and mitochondrial NDI and COI genes. The molecular data also indicated that Vietnamese aspermic triploids might be hybrids and/or their offspring between Fasciola hepatica and F. gigantica, because they showed the ITS1-Fh/Fg haplotype, which had chimeric sequences of the two species. Furthermore, the aspermic triploids seem to have originated in countries other than Vietnam and to have rapidly spread to that country with infected animals.
authors.affiliation: Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka 020-8550, Japan. itagaki@iwate-u.ac.jp
authors.forename: Tadashi
authors.initials: T
authors.lastname: Itagaki
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sakaguchi
authors.forename: Kunio
authors.initials: K
authors.lastname: Terasaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Sasaki
authors.forename: Shinobu
authors.initials: S
authors.lastname: Yoshihara
authors.forename: Truong
authors.initials: T
authors.lastname: Van Dung
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases; D018509:DNA, Helminth / Q000032:analysis / Q000235:genetics; D004272:DNA, Mitochondrial / Q000032:analysis* / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000032:analysis / Q000235:genetics; D004171:Diploidy; D003576:Electron Transport Complex IV / Q000235:genetics; D005209:Fasciola / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D005211:Fascioliasis / Q000469:parasitology / Q000662:veterinary; D008297:Male; D009245:NADH Dehydrogenase / Q000235:genetics; D011123:Polyploidy; D013091:Spermatogenesis; D014744:Vietnam
chemical_list: D018509:DNA, Helminth; D004272:DNA, Mitochondrial; D021903:DNA, Ribosomal Spacer; D009245:NADH Dehydrogenase; D003576:Electron Transport Complex IV