Molecular barcoding and phylogeography of sexual and asexual freshwater planarians of the genus Dugesia in the Western Mediterranean (Platyhelminthes, Tricladida, Dugesiidae).
Planarians of the genus Dugesia have a worldwide distribution with high species diversity in the Mediterranean area. In this area, populations with a triploid karyotype that reproduce by fissiparity are exceptionally frequent, outnumbering the sexual populations. This situation poses interesting questions, such as the age of these asexual lineages, whether they all belong to the same species or whether the triploidization event is recurrent, and what factors (climatic, geographical, historical...) explain the prevalence of these asexual forms. However, asexual populations cannot be assigned to a species due to the lack of copulatory apparatus--the main structure used in species identification. In this study, we have developed a DNA barcoding method, based on COI and ITS-1 sequences, which allows the assignment of the fissiparous forms to sexual species. At the same time, phylogenetic analysis from species of the western Mediterranean have unveiled the presence of species with highly differentiated populations alongside species with a wide distribution and almost no genetic variation. The roles of habitat instability, dispersal capacity and human activities are briefly discussed.
Institut de Recerca de la Biodiversitat i, Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain. evalazaro@ub.edu
Eva M
EM
Lázaro
Ronald
R
Sluys
Maria
M
Pala
Giacinta Angela
GA
Stocchino
Jaume
J
Baguñà
Marta
M
Riutort
D000818:Animals; D001483:Base Sequence; D018509:DNA, Helminth / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D008522:Mediterranean Sea; D008969:Molecular Sequence Data; D010802:Phylogeny; D010932:Planarians / Q000145:classification / Q000235:genetics*; D012100:Reproduction, Asexual / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA / Q000379:methods*
D018509:DNA, Helminth; D004272:DNA, Mitochondrial; D021903:DNA, Ribosomal Spacer