title: Genetic relationships between Atlantic and Pacific populations of the notothenioid fish Eleginops maclovinus: the footprints of Quaternary glaciations in Patagonia.
abstract: The genetic relationships between the Pacific and the Atlantic populations of marine coastal biota in Southern South America have been analyzed in few studies, most of them relying on a single mitochondrial locus. We analyzed 10 polymorphic microsatellite loci, isolated from a dinucleotide-enriched Eleginops maclovinus genomic library, in a total of 240 individuals (48 from each of 5 sampled sites: 2 Atlantic, 2 Pacific and 1 in Beagle Channel). The results were contrasted against a previous work on the same species with mitochondrial DNA (mtDNA). Observed heterozygosity within localities ranged from 0.85 to 0.88 with the highest overall number of alleles observed at the northernmost locality on the Pacific side (Concepción), but no clear geographic pattern arose from the data. On the other hand, the number of private alleles was negatively correlated with latitude (Spearman's rs test, P=0.017). Among-population variance was low but significant (1.35%; P<0.0001, analysis of molecular variance (AMOVA)) and low genetic differentiation between populations was observed (pairwise FST values ranged from 0 to 0.021). A Mantel test revealed a significant correlation between geographic distances and FST (r=0.56, P=0.047). This could be partially accounted by the Atlantic versus Pacific population differentiation detected in three different analyses (STRUCTURE, SAMOVA (Spatial Analysis of MOlecular VAriance) and a population phylogeny). The observed pattern is compatible with a history of separation into two glacial refugia that was better captured by the multilocus microsatellite data than by the mtDNA analysis.
authors.affiliation: Centro Austral de Investigaciones Científicas (CADIC), Ushuaia, Argentina.|Universidad Nacional de Tierra del Fuego (UNTDF), Ushuaia, Argentina.
authors.forename: S G
authors.initials: SG
authors.lastname: Ceballos
authors.affiliation: Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
authors.forename: E P
authors.initials: EP
authors.lastname: Lessa
authors.affiliation: Institute for the Oceans and Fisheries University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Licandeo
authors.affiliation: Centro Austral de Investigaciones Científicas (CADIC), Ushuaia, Argentina.|Universidad Nacional de Tierra del Fuego (UNTDF), Ushuaia, Argentina.
authors.forename: D A
authors.initials: DA
authors.lastname: Fernández
mesh_terms: D000483:Alleles; D000818:Animals; D001499:Bayes Theorem; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D051456:Gene Flow; D005828:Genetics, Population; D005843:Geography; D018895:Microsatellite Repeats; D008957:Models, Genetic; D010473:Perciformes / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013020:South America
chemical_list: D004272:DNA, Mitochondrial