Genetic relationships among populations of northern pike (Esox lucius)

Abstract

We assessed genetic variation, using microsatellite markers, in 14 populations of northern pike (Esox lucius) in the North Central United States and in six populations from Quebec, Alaska, Siberia, and Finland. Eight of 13 loci examined were polymorphic in at least one population with an average heterozygosity at all loci and across all populations of 0.14. The R st and F st values indicated differentiation among populations (R st = 0.61, F st = 0.42). Although microsatellite variation found in northern pike was much lower than that found in sympatric and other fish species, the polymorphisms differentiated populations of greater geographical proximity than was possible in prior studies using allozymes and mitochondrial DNA. We generated UPGMA-clustering phenograms based on five genetic distance measures with 2000 bootstrap replicates per measure. All measures yielded highly repeatable population structure between continents (supporting values = 92.4-100%) and within Finland (42.3-98%). Four measures differentiated the Alaskan population and Young Lake (Great Lakes drainage) from other North American populations (56.6-87.7%). Relationships among other North Central United States populations were unclear, as indicated by low supporting values. Results support the hypotheses of one refugium in the North Central United States and more than one refugium in Europe during the last glaciation.Résumé : Nous avons évalué, au moyen de marqueurs microsatellites, la variation génétique dans 14 populations de grand brochet du centre-nord des États-Unis et dans six populations du Québec, de l'Alaska, de la Sibérie et de la Finlande. Huit des 13 loci examinés étaient polymorphes dans au moins une population, et l'hétérozygotie moyenne pour l'ensemble des loci de toutes les populations était de 0,14. Les valeurs de R st et F st indiquaient une différenciation parmi les populations (R st = 0,61, F st = 0,42). Alors que la variation des microsatellites observée chez le grand brochet était de beaucoup inférieure à celle observée chez des espèces sympatriques et chez d'autres espèces, notre examen des polymorphismes a permis de différencier des populations plus rapprochées géographiquement que celles différenciées dans des études antérieures utilisant des allozymes et l'ADN mitochondrial. Nous avons produit des phénogrammes par groupement UPGMA à partir de cinq mesures de la distance génétique, avec 2 000 réplicats bootstrap par mesure. Toutes les mesures ont donné une structure de population très constante entre continents (valeurs du bootstrap = 92,4-100%) et à l'intérieur de la Finlande (42,3-98%). Quatre mesures ont différencié les populations de l'Alaska et du lac Young (bassin des Grands Lacs) des autres populations nord-américaines (56,6-87,7%). Les relations entre les autres populations du centre-nord des États-Unis n'étaient pas claires, comme l'indiquent les basses valeurs du bootstrap. Nos résultats laissent croire qu'il y a eu un seul refuge dans le centre-nord des États-Unis et plus d'un refuge en Europe durant la derni...

Stocking impact and temporal stability of genetic composition in a brackish northern pike population (Esox lucius L.), assessed using microsatellite DNA analysis of historical and contemporary samples

“…The observation of temporal stability in the pike population in Stege Nor corresponds with previous studies on temporal stability of both trout and salmon populations over time scales as long as 80-100 years (Nielsen et al, 1997;Tessier and Bernatchez, 1999;Hansen et al, 2002;Hansen, 2002). In addition, we found a high degree of genetic differentiation among all pike populations studied, which corresponds with previous studies on pike populations in Denmark and around the Finnish part of the Baltic Sea Senanan and Kapuscinski, 2000;Jakobsen et al, 2005). These observations reflect the evolutionary history of the area and the relatively small effective population sizes within individual lakes (Miller and Kapuscinski, 1997).…”

“…Until recently, it has not been feasible to apply genetic markers for evaluating the effects of pike stocking activity, due to extremely low levels of genetic variability at the allozyme and mitochondrial DNA level (Healy and Mulcahy, 1980;Seeb et al, 1987;Brzuzan et al, 1998;Maes et al, 2003). However, recent development of microsatellite markers for pike has provided efficient tools for studying the genetic population structure Kapuscinski, 1996, 1997;Hansen et al, 1999;Senanan and Kapuscinski, 2000;Miller et al, 2001). The purpose of this study was to analyse the genetic impact of a decade of stocking freshwater pike into an indigenous brackish pike population of the Stege Nor fjord on the island of M n, Denmark.…”

Genetic differentiation among populations ofBaetis rhodani(Ephemeroptera, Baetidae) in three Italian streams

“…The population structure analysis of each drainage and of the entire data set were based on Wright's index F ST (Weir & Cockerham, 1984) that allows us to determine genetic differentiation of populations (Senanan & Kapuscinski, 2000). F ST is a measure of the relative fixation of alternate alíeles in different subpopulations (Weir & Cockerham, 1984) and allows comparisons among populations.…”

Circumpolar phylogeography of the northern pike (Esox lucius) and its relationship to the Amur pike (E. reichertii)

“…The geographic origin of the genus Esox is unclear. The relatively higher number of species in North America, together with fossil evidence [7], has led to the suggestion that the genus originated on this continent [8].…”