Ethanol-fixed material used for both classical and molecular identification purposes: Eudiplozoon nipponicum (Monogenea: Diplozoidae) as a case parasite species
Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlárská 2, 611 37, Brno, Czech Republic. Parasitology Research
(Impact Factor: 2.1).
09/2010; 107(4):909-14. DOI: 10.1007/s00436-010-1949-0
This study is focused on the feasibility of two treatments of alcohol-fixed monogenean parasites which are intended to be use for the combined morphological and molecular characterizations. The monogenean parasite, Eudiplozoon nipponicum, was selected as a model parasite species; however it is expected that these techniques will be suitable for other monogeneans and other parasitic families. The haptor of diplozoid parasites is equipped with sclerotized attachment clamps and central hooks which are utilized for morphological identification. As parasite tissue become very tough and rigid when preserved in ethanol, using these structures for species identification without additional treatment is difficult. We investigated two different techniques to digest the surrounding tissues, the first was treatment with 10% sodium dodecyl sulphate (SDS) and the second treatment was proteinase K. Tissue was successfully digested in both treatments and all clamps, central hook and even individual sclerites of the clamps were clearly visible and well defined. After treatment, the digest was used to extract genomic DNA, and the second internal transcribed spacer of the ribosomal DNA genes (rDNA) was amplified. Nucleic acid sequence was obtained from 90% of parasite specimens processed by both treatments. Treatment of haptors with SDS was proven to be more successful with no visible changes or damage observed to sclerites even after a month. This method represents a useful tool for the combined morphological and molecular studies as the correct sequence can be assigned to the same individual worm from which haptoral parts have been obtained.
Available from: Jean-Lou Justine
- "The interest in describing new methods is still alive and many recently published works address specific parasites or methods (Albuquerque et al. 2009;Bruno et al. 2006;Cribb et al. 2004;Deveney and Whittington 2001;Galli et al. 2006;Galli et al. 2007;Parker et al. 2010;Snyder and Clopton 2005;Wong et al. 2006). The emergence of molecular methods has prompted a renewed interest in methods which can process material for both morphological and molecular methods (Harris et al. 1999;Košková et al. 2011;Naem et al. 2010;Strona et al. 2009;Toe et al. 1997;Yoder et al. 2006). We propose here a method for collecting parasites which can be used by any person who has at least some basic knowledge of vertebrate anatomy, but has no specific training in parasitology. "
Available from: Davide Seveso
- "The widespread use of sclerites is also related to the fact that, thanks to their chemical composition, they are the least perishable monogenean structures, allowing species identification even for specimens that are not optimally preserved. This is important, because the best way to prepare monogenean slides for long-term preservation is debated, and incorrect preparation may produce serious morphological artefacts (Wong et al. 2006; Strona et al. 2009; Ko skov a et al. 2010; Justine et al. 2012). However, not all sclerotized structures may be clearly visible on prepared materials, because of different reasons, such as a suboptimal orientation of specimen on slide, or the chemical properties of the media used for preservation (Galli et al. 2007). "
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ABSTRACT: We introduce a new statistical method to select which morphological characters are most useful to identify monogenean species. The method estimates the average size overlap of candidate diagnostic structures among a set of species to individuate those that mostly differ between the species. To dem-onstrate our approach, we report a comprehensive analysis conducted on two of the most species-rich monogenean genera: Dactylogyrus Diesing, 1850 and Gyrodactylus von Nordmann, 1832. We demonstrate that, in contrast to common taxonomic practice, very few but highly diagnostic mea-surements are necessary to correctly identify a specimen. In particular, we found that most of Dactylogyrus and Gyrodactylus species can be classified on the basis of the width of the supplementary connecting bar and of the length of the hook sickle, respectively.
Available from: Mustafa Koyun
- "For morphometric analysis, only one opisthaptor of each specimen was cutoff (Khotenovsky 1974) and soaked in 10 % sodium dodecyl sulfate for 30– 60 min. This was done in order to soften rigid tissue and thereby to make the clamps and central hooks clearly visible (Wong et al. 2006; Košková et al. 2010). The treated opisthaptor was washed in distilled water before being mounted on a microscope slide and fixed with a mixture of ammonium picrate and glycerin (Malmberg 1956; Khotenovsky 1974). "
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ABSTRACT: The paper presents a description of Paradiplozoon bingolensis sp. n. from the gills of Garra rufa Heckel, 1843 (Cyprinidae) collected from the Göynük Stream, a tributary of the Murat River, Turkey. This is the first diplozoid species to be described from G. rufa. P. bingolensis is distinguished from the other valid species in the genus by the combination of the morphology of the sclerites of its clamps and by the size of the central hooks. Even molecular characterization based on variability of the second internal transcribed spacer (ITS2) of the ribosomal DNA region provided additional support of separation of this new species from the valid ones. The sequences were compared with previously published ITS2 sequences of other diplozoid species. Subsequent analysis demonstrated the uniqueness of this new parasite species and revealed uncertainties in the current taxonomic division of the Diplozoidae that are commented in the text.
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