Phylogeography and Conservation Genetics of the Ibero-Balearic Three-Spined Stickleback (Gasterosteus aculeatus)

• Published in: PloS one 2017-01, Vol.12 (1), p.e0170685-e0170685
• Main Authors: Vila, Marta, Hermida, Miguel, Fernández, Carlos, Perea, Silvia, Doadrio, Ignacio, Amaro, Rafaela, San Miguel, Eduardo
• Format: Article
• Language: English
• Subjects: Analysis; Animal behavior; Animals; Basins; Biodiversity; Biological evolution; Biology and Life Sciences; Computer and Information Sciences; Conservation; Conservation genetics; Conservation of Natural Resources; Crosses, Genetic; Cytochrome; Cytochrome b; Cytochromes b - genetics; DNA - genetics; DNA, Mitochondrial - genetics; Drainage basins; Drainage systems; Earth Sciences; Ecological monitoring; Ecology and Environmental Sciences; Endangered & extinct species; Endangered Species; Environmental policy; Environmental protection; Ethics; Evolution; Evolution, Molecular; Evolutionary biology; Extinct species; Fish; Fisheries; Fisheries management; Gasterosteus aculeatus; Gene sequencing; Genetic aspects; Genetic diversity; Genetic Drift; Genetic isolation; Genetic variability; Genetic Variation; Genetics; Genetics, Population; Genomes; Haplotypes - genetics; Introduced species; Limia; Microsatellite Repeats; Mitochondria; Peripheral populations; Phylogeny; Phylogeography; Population; Population Dynamics; Population genetics; Population structure; Populations; Portugal; Protected species; Protection and preservation; Reintroduction; Reproductive Isolation; Rivers; Sequence Analysis, DNA; Smegmamorpha - genetics; Spain; Species extinction; Sticklebacks; Studies; Teleostei; Variability; Wildlife conservation
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0170685

Genetic isolation and drift may imperil peripheral populations of wide-ranging species more than central ones. Therefore, information about species genetic variability and population structure is invaluable for conservation managers. The Iberian populations of three-spined stickleback lie at the southwestern periphery of the European distribution of Gasterosteus aculeatus. This teleost is a protected species in Portugal and Spain and local extinctions have been reported in both countries during the last decades. Our objectives were (i) to determine whether the Iberian populations of G. aculeatus are unique or composed of any of the major evolutionary lineages previously identified and (ii) to assess the evolutionary potential of these peripheral populations. We genotyped 478 individuals from 17 sites at 10 polymorphic microsatellite loci to evaluate the genetic variability and differentiation of the Ibero-Balearic populations. We also sequenced 1,165 bp of the mitochondrial genome in 331 of those individuals in order to complement the estimates of genetic diversity in the Ibero-Balearic region. We predicted the evolutionary potential of the different sites analysed based on the contribution of each of them to total allelic/mitochondrial diversity. An intraspecific phylogeny at European level was reconstructed using our data from the mitochondrial cytochrome b gene (755 bp) and published sequences. The so-called Transatlantic, European and Mediterranean mitochondrial lineages were found to be present in the Ibero-Balearic region. Their phylogeography suggests a history of multiple colonisations. The nuclear results show, however, a strong correlation between population structure and drainage system. The following basins should be prioritised by conservation policies in order to preserve those populations with the highest evolutionary potential: the Portuguese Vouga and Tagus as well as the Spanish Majorca and Limia. Maintenance of their connectivity, control of exotic species and monitoring of habitat properties are strongly recommended in those areas. Genetic variation alone cannot, however, ensure the persistence of these peripheral southern populations of G. aculeatus. On the one hand, the analysis of a historical sample from Eastern Spain (Penyscola) revealed no genetic erosion, which suggests a fairly sudden extinction of that population. On the other hand, the reintroduction program implemented in the Valencian Community has mostly failed despite our