Molecular markers for taxonomic identification and phylogeny of the species of the genus Dugesia in the western Mediterranean
Baguñà, J.; Carranza, S.; Riutort, M. (2001). Molecular markers for taxonomic identification and phylogeny of the species of the genus Dugesia in the western Mediterranean. Belg. J. Zool. 131(Suppl. 1): 60
In: Belgian Journal of Zoology. Koninklijke Belgische Vereniging voor Dierkunde = Société royale zoologique de Belgique: Gent. ISSN 0777-6276; e-ISSN 2295-0451, more
Also appears in:Saló, E.; Watson, N.; Schockaert, E. (Ed.) (2001). Proceedings of the 9 th International Symposium on the Biology of the Turbellaria, Barcelona, Spain, June 2000. Belgian Journal of Zoology, 131(Suppl. 1). Koninklijke Belgische Vereniging voor Dierkunde = Société royale zoologique de Belgique: Diepenbeek. 236 pp., more
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Document type: Summary
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| Authors | | Top |
- Baguñà, J.
- Carranza, S.
- Riutort, M.
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| Abstract |
The genus Dugesia (Gérard, 1850) comprises up to 70 described species, formerly included within the so-called species group or species complex Dugesia gonocephala sensu lato (s.I.), widely distributed in Africa and the Paleartic and Oriental regions. In the western Mediterranean, eight species of Dugesia have so far been reported. In this area, however, fissiparous populations clearly outnumber conspecific sexual populations. Because in Dugesia most species (the exceptions being Dugesia hepta and Dugesia sicula) have karyotypes that are a multiple of a basic haploid number of eight with almost identical karyograms, and because polyploidies, aneuploidies and the presence of B-chromosomes have been frequently reported, karyotypic analyses are of little help to assign fissiparous populations to their sexual counterparts. In addition the phylogenetic relationships between these species are still far from clear. Here, we review the recent application of molecular markers that identify species or groups of species and that lead to a tentative new phylogeny for the species studied. In particular, we discuss results using sequences of the internal transcribed spacer region (ITS-l ) of ribosomal DNA, the presence/absence of a family of long interspersed repeated elements (Del) firSt isolated in Dugesia etrusca (BATISTONI et al, 1999) and restriction pattern analysis of rDNA (BATISTONI et al, 1999). Main results were: 1) ITS-l sequences and Del contribute useful qualitative markers to identify single species or groups of species; 2) distance and parsimony analyses drawn from ITS-l sequences show two main phylogenetic assemblages within the species studied, with a good internal resolution; and 3) all asexual populations were unambiguously assigned to particular sexual species. These results show the usefulness of a molecular approach to taxonomy and phylogeny and the need to make congruent morphologically-based and molecularly-based taxonomies and phylogenies. |
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