Advertisement

Parasitology Research

, Volume 86, Issue 9, pp 738–744 | Cite as

Relationships among some ascaridoid nematodes based on ribosomal DNA sequence data

  • Xingquan Zhu
  • Robin B. Gasser
  • Dennis E. Jacobs
  • Guo-Chiuan Hung
  • Neil B. Chilton
ORIGINAL PAPER

Abstract

The nuclear ribosomal DNA (rDNA) region spanning the first (ITS-1) and second (ITS-2) internal transcribed spacers was sequenced for 15 taxa of ascaridoid nematodes. The length of the ITS-1 and ITS-2 sequences in the 15 taxa ranged from 392–500 bp and 240–348 bp, respectively. While nucleotide variation of 0–2.9% in the ITS-1 and/or ITS-2 sequences was detected within taxa where multiple samples were sequenced, significantly higher level of nucleotide difference (9.4–66.6%) was detected between the taxa, except for Ascaris suum and A. lumbricoides whose taxonomic status remains uncertain. These interspecific differences were linked with the considerable size differences (0–108 bp) in the rDNA spacers. Phenograms based on the genetic differences among the 15 taxa showed some concordance with previous classification schemes derived from morphological data.

Keywords

Classification Scheme Nucleotide Variation Size Difference Morphological Data Ascaris 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Xingquan Zhu
    • 1
  • Robin B. Gasser
    • 1
  • Dennis E. Jacobs
    • 2
  • Guo-Chiuan Hung
    • 1
  • Neil B. Chilton
    • 1
  1. 1.Department of Veterinary Science, The University of Melbourne, 250 Princes Highway, Werribee, Victoria 3030, Australia e-mail: r.gasser@vet.unimelb.edu.au Tel.: +61-3-97428283; Fax: +61-3-97410401AU
  2. 2.Department of Pathology and Infectious Diseases, The Royal Veterinary College, University of London, North Mymms, Hatfield AL9 7TA, UKGB

Personalised recommendations