Phylogeography and population structure of the Atlantic and Mediterranean green turtle Chelonia mydas: a mitochondrial DNA control region sequence assessment

Publication Type:Journal Article
Year of Publication:1996
Authors:Encalada, S. E., Lahanas, P. N., Miyamoto, M. M., Bjorndal, K. A., Bolten, A. B., Bowen, B. W.
Journal:Molecular Ecology
Volume:5
Pagination:473-483
Keywords:biogeography, Chelonia mydas, control, dispersal, Mitochondrial DNA, PCR, phylogeography, region, sequencing
Abstract:

Mitochondrial (mt) DNA sequences were analysed to resolve the phylogeography and population genetic structure of Atlantic and Mediterranean populations of green turtles ( Chelonia mydas ). Analysis of sequence variation over 487 base pairs of the control ( D loop) region identified 18 haplotypes amonf 147 individuals from nine nesting populations. Pairwise comparisons of haplotype frequencies distinguished most nesting colonies, indicating significant genetic differention among rookeries and a strong propensity for natal homing behaviour by nesting females. Comparison of control region sequence data to earlier restiction fragment length polymorphism (RFLP) data for the same indivituals demonstrates approximately a sixfold higher resolution both in terms of the number of mtDNA genotype variants and thw phylogeographics relationships detected within the Atlantic region, and reveal a gene genealogy that distinguishes two groups of haplotypes corresponding to (i) the western Caribbean and Mediterranean, and (ii) eastern Caribbean, South Atlantic Ocean may be interpreted in terms of female nest site fidelity and episodic dispersal events. The distribution of mtDNA haplotypes within thw region is thus explained by the geological and climatic alternations (glacial amd interglacial) over the last million years.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith