Phylogenetic analysis of partial mitochondrial cytochrome oxidase c subunit I and large ribosomal RNA sequences and nuclear internal transcribed spacer I sequences from species of Cyathostominae and Strongylinae (Nematoda, Order Strongylida), parasites of the horse.
Abstract: Three nucleotide data sets, one nuclear (ITS-2) and two mitochondrial (COI and l-rRNA), have been investigated in order to determine relationships among species of Strongylinae and Cyathostominae, intestinal parasites of the horse. The data exhibited a strong mutational bias towards A and T and in the COI gene, silent sites appeared to saturate rapidly partly due to this substitution bias. Thus, the COI gene was found to be less phylogenetically informative than the l-rRNA and ITS-2 genes. Combined analysis of the l-rRNA and ITS-2 genes supported a monophyletic clade of the cyathostomes with Tridentoinfundibulum gobi, which had previously been classified as a nematode of' uncertain origin'. The Strongylinae grouped consistently outside the clade containing the cyathostomes and T. gobi. Molecular analysis failed to provide strong evidence for the separation of cyathostomes into classical genera, as previously defined by morphological classification.
Publication Date: 2001-01-13 PubMed ID: 11155936DOI: 10.1017/s003118200000696xGoogle Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This study examines the genetic relationships between species of horse intestinal parasites, using analysis of both nuclear and mitochondrial gene sequences. The research found that the cytochrome oxidase c subunit I gene is less informative for phylogenetic evaluation compared to large ribosomal RNA and internal transcribed spacer I genes.
Introduction and Investigations
- The study began with an evaluation of three different nucleotide data sets – one nuclear (ITS-2) and two mitochondrial (COI and l-rRNA). These data sets were used to determine the relationships between species of Strongylinae and Cyathostominae, which are both subtypes of internal parasites in horses.
- The researchers observed a strong mutational bias towards adenine and thymine (A and T) in the selected genetic sequences. Additionally, in the COI gene, there were rapidly saturating silent sites, which are nucleotide positions that do not affect the coded protein. This was partially due to the identified substitution bias.
Findings
- The COI gene was found to be less phylogenetically informative, meaning it was less useful in determining evolutionary relationships among the studied organisms. This is compared to the l-rRNA and the ITS-2 genes which provided more valuable evolutionary information.
- Analysis combining data from the l-rRNA and ITS-2 genes recognized a single origin group (monophyletic clade) that included the cyathostomes and a relatively obscure nematode species, Tridentoinfundibulum gobi. This nematode had previously been classified as a nematode of ‘uncertain origin’ due to lack of understanding about its evolutionary origins.
- The Strongylinae parasites consistently positioned outside this identified clade, meaning they showed distinct genetic characteristics different from the group that included the cyathostomes and T. gobi.
Implications
- This study’s molecular analysis did not strongly support the separation of cyathostomes into their traditionally defined genera, which was based on physical appearance. This means that the way these parasites have been classified on a genetic level may not reflect their morphological categories, indicating a need for re-evaluation of parasite classification methods.
Cite This Article
APA
McDonnell A, Love S, Tait A, Lichtenfels JR, Matthews JB.
(2001).
Phylogenetic analysis of partial mitochondrial cytochrome oxidase c subunit I and large ribosomal RNA sequences and nuclear internal transcribed spacer I sequences from species of Cyathostominae and Strongylinae (Nematoda, Order Strongylida), parasites of the horse.
Parasitology, 121 Pt 6, 649-659.
https://doi.org/10.1017/s003118200000696x Publication
Researcher Affiliations
- Department of Veterinary Parasitology, University of Glasgow Veterinary School. amcd@molgen.gla.ac.uk
MeSH Terms
- Animals
- DNA, Helminth / chemistry
- DNA, Ribosomal Spacer / chemistry
- Electron Transport Complex IV / genetics
- Horse Diseases / parasitology
- Horses
- Mitochondria / enzymology
- Mitochondria / genetics
- Molecular Sequence Data
- Phylogeny
- RNA, Ribosomal / chemistry
- Strongylida / classification
- Strongylida / genetics
- Strongylida Infections / parasitology
- Strongylida Infections / veterinary
Citations
This article has been cited 10 times.- Courtot É, Boisseau M, Dhorne-Pollet S, Serreau D, Gesbert A, Reigner F, Basiaga M, Kuzmina T, Lluch J, Annonay G, Kuchly C, Diekmann I, Krücken J, von Samson-Himmelstjerna G, Mach N, Sallé G. Comparison of two molecular barcodes for the study of equine strongylid communities with amplicon sequencing. PeerJ 2023;11:e15124.
- Louro M, Kuzmina TA, Bredtmann CM, Diekmann I, de Carvalho LMM, von Samson-Himmelstjerna G, Krücken J. Genetic variability, cryptic species and phylogenetic relationship of six cyathostomin species based on mitochondrial and nuclear sequences. Sci Rep 2021 Apr 15;11(1):8245.
- Gao Y, Zhang Y, Yang X, Qiu JH, Duan H, Xu WW, Chang QC, Wang CR. Mitochondrial DNA Evidence Supports the Hypothesis that Triodontophorus Species Belong to Cyathostominae. Front Microbiol 2017;8:1444.
- Bredtmann CM, Krücken J, Murugaiyan J, Kuzmina T, von Samson-Himmelstjerna G. Nematode Species Identification-Current Status, Challenges and Future Perspectives for Cyathostomins. Front Cell Infect Microbiol 2017;7:283.
- Galbreath KE, Hoberg EP. Return to Beringia: parasites reveal cryptic biogeographic history of North American pikas. Proc Biol Sci 2012 Jan 22;279(1727):371-8.
- Nakano T, Okamoto M, Ikeda Y, Hasegawa H. Mitochondrial cytochrome c oxidase subunit 1 gene and nuclear rDNA regions of Enterobius vermicularis parasitic in captive chimpanzees with special reference to its relationship with pinworms in humans. Parasitol Res 2006 Dec;100(1):51-7.
- Posedi J, Drögemüller M, Schnieder T, Höglund J, Lichtenfels JR, von Samson-Himmelstjerna G. Microchip capillary electrophoresis-based genetic comparison of closely related cyathostomin nematode parasites of horses using randomly amplified polymorphic DNA polymerase chain reaction. Parasitol Res 2004 Mar;92(5):421-9.
- Jia H, Tang L, Fu Y, Xiong Y, Yan L, Shao C, Li K, Zhang D, Hu D. The first mitogenome of Petrovinema skrjabini from Equus ferus przewalskii: a phylogenetic analysis within the Strongylidae family. Parasit Vectors 2025 Jul 11;18(1):278.
- Jia H, Chu W, Zhang D, Li K, Huang W, Li X. Morphology, Molecular Characterization, and Phylogeny of Travassosius rufus Khalil, 1922 (Strongylidea: Trichostrongylidae), a Parasite from Endangered Sino-Mongolian Beaver (Castor fiber birulai) in Xinjiang, China. Animals (Basel) 2025 May 6;15(9).
- Mannan MA, Chowdhury S, Hossain MA, Kabir MHB. Genetic variability of Haemonchus contortus isolates in small ruminants from slaughterhouses in Bangladesh. Parasitol Res 2023 Dec;122(12):3101-3107.
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