title: First complete large subunit ribosomal RNA sequence and secondary structure for a parasitic nematode: phylogenetic and diagnostic implications.
abstract: The complete sequence and secondary structure of the large subunit of nuclear ribosomal RNA(LSUrRNA) were determined for the parasitic nematode Labiostrongylus bipapillosus (order Strongylida). Its LSU rRNA sequence was shorter (by 18 bp) than that of the free-living nematode, Caenorhabditis elegans (order Rhabditida), the only other species within the Nematoda for which a complete LSU rRNA sequence has been determined. Interspecific differences in sequence were greater in the 12 D domains compared with the core segments, with the secondary structure being maintained by partial or complete compensatory base pair changes. The magnitude of interspecific sequence difference in each D domain (except for D6 and D12) was similar, suggesting that several domains contain informative genetic markers for phylogenetic studies of the phylum Nematoda at different taxonomic levels. The LSU rRNA may also provide species-specific markers for the identification of some bursate nematodes of veterinary and medical importance.
authors.affiliation: Department of Veterinary Science, The University of Melbourne, 250 Princes Highway, Werribee, Victoria 3030, Australia. n.chilton@vet.unimelb.edu.au
authors.forename: Neil B
authors.initials: NB
authors.lastname: Chilton
authors.forename: Florence
authors.initials: F
authors.lastname: Huby-Chilton
authors.forename: Robin B
authors.initials: RB
authors.lastname: Gasser
mesh_terms: D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D020459:Genes, rRNA; D005819:Genetic Markers / Q000235:genetics; D008969:Molecular Sequence Data; D009348:Nematoda / Q000235:genetics; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D018510:RNA, Helminth / Q000737:chemistry*; D012335:RNA, Ribosomal / Q000737:chemistry* / Q000235:genetics; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D017206:Strongylida Infections / Q000175:diagnosis; D013320:Strongyloidea / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D018510:RNA, Helminth; D012335:RNA, Ribosomal; D012339:RNA, Ribosomal, 28S; D012340:RNA, Ribosomal, 5.8S; C065096:RNA, ribosomal, 26S