Delineation of Two Sibling Red Algal Species,Gracilaria Gracilis and Gracilaria Dura (Gracilariales,Rhodophyta), Using Multiple DNA Markers: Resurrection of the Species G. Dura Previously Described in the Northern Atlantic 200 Years Ago1 |
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Authors: | Christophe Destombe Myriam Valero Marie Laure Guillemin |
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Institution: | 1. Université Pierre et Marie Curie‐ Paris 6, UMR 7144, Equipe “BEDIM”, Adaptation & Diversité en Milieu Marin, Station Biologique, Place Georges Teissier, F‐29682 Roscoff Cedex, France,CNRS, UMR 7144, Station Biologique, Place Georges Teissier, F‐29682 Roscoff Cedex, France;2. Author for correspondence: e‐mail .;3. Instituto de Ecología y Evolución, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile |
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Abstract: | Molecular markers belonging to the three different genomes, mitochondrial (cox2‐cox3 spacer), plastid (rbcL), and nuclear (internal transcribed spacer ITS] 2 region), were used to compare samples of the two morphologically related species Gracilaria gracilis (Stackh.) Steentoft, L. M. Irvine et Farnham and G. dura (C. Agardh) J. Agardh collected along Atlantic coasts. In northern Europe, the distinction between these two species is ambiguous, and they are currently recognized under the single name of G. gracilis. The low but congruent patterns of genetic divergence observed for markers of the three genomic compartments highly suggest that these two taxa correspond effectively to two different genetic entities as previously described 200 years ago, based on morphological traits. However, thanks to the combination of different DNA markers, occurrence of “incongruent” cytotypes (i.e., mitotypes of G. dura associated with chlorotypes of G. gracilis) in individuals collected from Brittany, suggests interspecific hybridization between the two sibling species studied. |
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Keywords: | barcoding cox2‐cox3 spacer cyto‐nuclear linkage disequilibrium hybridization introgression ITS rbcL Rhodophyta |
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