Genetic relationships between Atlantic and Pacific populations of the notothenioid fish Eleginops maclovinus: the footprints of Quaternary glaciations in Patagonia.

CEBALLOS, SANTIAGO GUILLERMO; LESSA, E. P.; LICANDEO, R.; FERNÁNDEZ, DANIEL A.

HEREDITY

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2016 vol. 116 p. 372 - 377

0018-067X

The genetic relationships between the Pacific and the Atlantic populations of marine coastal biota in Southern South Americahave been analyzed in few studies, most of them relying on a single mitochondrial locus. We analyzed 10 polymorphicmicrosatellite 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 previouswork on the same species with mitochondrial DNA (mtDNA). Observed heterozygosity within localities ranged from 0.85 to 0.88with the highest overall number of alleles observed at the northernmost locality on the Pacific side (Concepción), but no cleargeographic pattern arose from the data. On the other hand, the number of private alleles was negatively correlated with latitude(Spearman?s r s test, P = 0.017). Among-population variance was low but significant (1.35%; Po0.0001, analysis of molecularvariance (AMOVA)) and low genetic differentiation between populations was observed (pairwise F ST values ranged from 0 to0.021). A Mantel test revealed a significant correlation between geographic distances and F ST (r = 0.56, P = 0.047). This couldbe 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 historyof separation into two glacial refugia that was better captured by the multilocus microsatellite data than by the mtDNA analysis.