Holarctic Phylogeography of Arctic Charr (Salvelinus Alpinus L.) Inferred From Mitochondrial Dna Sequences

Abstract

This study evaluated mitochondrial DNA (mtDNA) sequence variation in a 552-bp fragment of the control region of Arctic charr (Salvelinus alpinus) by analyzing 159 individuals from 83 populations throughout the entire range of the complex. A total of 89 (16.1%) nucleotide positions were polymorphic, and these defined 63 haplotypes. Phylogenetic analyses supported the monophyly of the complex and assigned the observed haplotypes to five geographic regions that may be associated with different glacial refugia. Most notably, a formerly defined major evolutionary lineage (S. a. erythrinus) ranging from North America across the Arctic archipelago to the Eurasian continent has now been partitioned into the Arctic group and the newly identified Siberian group. The Beringian group, formed entirely by specimens assigned to S. malma (Dolly Varden), encompassed the area formerly assigned to S. a. taranetzi. The latter, due to a unique haplotype, became the basal member of the Arctic group. Overall, the S. alpinus complex reflects divergent evolutionary groups coupled with shallow intergroup differentiation, also indicated by an analysis of molecular variance that attributed 73.7% (P Ͻ 0.001) of the total genetic variance among groups. Time estimates, based on sequence divergence, suggest a separation of the major phylogeographic groups during early to mid-Pleistocene. In contrast, colonization of most of today's range started relatively recently, most likely late Pleistocene during the last retreat of ice sheets some 10,000-20,000 years ago. This time scale obviously is too shallow for detecting significant variation on a smaller scale using mtDNA markers. However, other studies using nuclear microsatellite DNA variation strongly suggested ongoing evolution within groups by revealing strong population-genetic substructuring and restricted gene flow among populations. Thus, Arctic charr could serve as a model organism to investigate the linkage between historical and contemporary components of phylogeographic structuring in fish, and, with a global perspective of the distribution of genetic variation as a framework, meaningful comparisons of charr studies at a smaller geographic scale will now be possible.

Mitochondrial DNA diversity and relationships of endemic charrs of the genus Salvelinus from Lake Kronotskoye (Kamchatka Peninsula)

“…Attempts to detect the genetic differentiation between sympatric morphotypes of lacustrine charrs, including those with different trophic specialization, on the basis of the mtDNA variability analysis (Danzmann et al, 1991;Brunner et al, 1998Brunner et al, , 2001Salmenkova et al, 2005;Radchenko et al, 2006) were mostly unsuccessful. A conclusion was made that the low resolution capability of mtDNA analysis is connected with a low general level of mtDNA diversity of charr fishes, whose historical ranges were in areas of cyclic glaciations in the Pleistocene (Brunner et al, 2001).…”

“…A conclusion was made that the low resolution capability of mtDNA analysis is connected with a low general level of mtDNA diversity of charr fishes, whose historical ranges were in areas of cyclic glaciations in the Pleistocene (Brunner et al, 2001). Salmenkova et al (2005) have shown that charrs of the Lake Kronotskoye basin are differentiated at allozyme loci and reliably (P \ 0.001) differ in the total estimate of five microsatellite loci.…”

Migration barriers protect indigenous brown trout (Salmo trutta) populations from introgression with stocked hatchery fish

“…Apparently most of the stocked individuals were able to contribute to the established populations, since stochastic processes accompanying the founding with only a few individuals did not alter the haplotype composition (Hansen and Mensberg 1996). On the other hand, it has been shown at length for brown trout (Berrebi et al 2000a,b;Borgstro¨m et al 2002;Caudron and Champigneulle 2002;Hansen et al 2002;Heggenes et al 2002), Atlantic salmon Salmo salar (Tessier and Bernatchez, 1999), Arctic chaff Salvelinus fontinalis (Brunner et al 2001;Englbrecht et al 2002) and grayling Thymallus thymallus (Koskinen et al 2002a) that stocking is inefficient whenever an indigenous population is present.…”

Geographic influences on fine-scale, hierarchical population structure in northern Canadian populations of anadromous Arctic Char (Salvelinus alpinus)

“…Genetic studies of Arctic populations of this species have generally focused on resolving phylogeographic structure (Wilson et al 1996;Brunner et al 2001), the evolution of ecotypic and morphological variation in sympatric populations (Arbour et al 2011;Moore et al 2013b) and relationships with closely-related species (e.g., Taylor et al 2008) whereas fine-scale assessments of population structure are very rare. Those that are available for anadromous populations in this species have typically resolved weak, but usually significant, genetic differentiation (Bernatchez et al 1998) and a high degree of straying (Moore et al 2013a).…”