The main objective of this study was to confirm the level of genetic differentiation observed amo... more The main objective of this study was to confirm the level of genetic differentiation observed among samples of fin whale collected at feeding grounds using a new dataset composed of 500 selected individuals genotyped for 15 microsatellite loci and the mtDNA was sequenced. New methods of amplification have been used (especially for the microsatellite loci) to successfully genotyped these selected individuals. Both types of genetic markers employed revealed a lack of genetic differentiation among samples collected and therefore suggest that extensive gene flow might prevail among fin whale population and/or that a recent population expansion of the species occurred. The signal of population expansion detected with the mtDNA might suggest that population of fin whale are not at equilibrium and that further analyses based on this information should be carried out (calculation of potential time of expansion and divergence). However, the comparison of these results to the allozyme data th...
The paper presents results of new statistical analyses of three old fin whale allozyme and carbon... more The paper presents results of new statistical analyses of three old fin whale allozyme and carbonic anhydrase datasets previously published in Árnason et al. (1992) Daníelsdóttir et al. (1991b & 1992a). The first dataset is on the genetic variation at 11 variable allozyme loci in 328 fin whales (Balaenoptera physalus) sampled in two North Atlantic areas; i.e. off West Iceland and Spain, a total of: 283 (Iceland 1985, 1986, 1987 and 1988) and 46 (Spain 1985) samples, respectively. The data is based on further analysis of genotypes at 11 allozyme loci: Ada, Ak-1, Gpd, Ldh-A, Mdh-S, Mpi-1, Pep-A, Pgm-1, Pgi and Sod-A. The new statistical programs applied here include FST, Confidence Intervals (CI) of FST, Nm, PCA, MDS, STRUCTURE and graphical illustration of potential “populations” as in Waples and Gaggiotti (2006). There was significant heterogeneity within each sample and overall samples, all due to heterozygote deficiency. Various genetic analyses on the dataset resulted in signific...
ABSTRACT The genetic structure of Atlantic herring Clupea harengus L. was investigated in its nor... more ABSTRACT The genetic structure of Atlantic herring Clupea harengus L. was investigated in its north-easterly distribution in the Norwegian Sea and adjacent waters, using 23 neutral and one non-neutral (Cpa111) microsatellite loci. Fish from the suspected 2 main populations—the Norwegian spring-spawning herring (NSSH) and the Icelandic summer-spawning herring (ISSH)—were collected at spawning locations in their respective spawning seasons from 2009 to 2012. Samples were also collected from Norwegian autumn spawning locations, from different local Norwegian fjords such as the inner part of Trondheimsfjorden, Lindås pollene, Landvikvannet and Lusterfjorden, as well as from suspected Faroese spawning components. The observed level of genetic differentiation was significant but low (FST = 0.007) and mostly attributable to the differentiation of the local Norwegian fjord populations. The locus Cpa111, which was detected to putatively be under positive selection, exhibited the highest FST value (0.044). The observed genetic patterns were robust to exclusion of this locus. Landvikvannet herring was also genetically distinguishable from the 3 other fjord populations. In addition, the present study does not support genetic structuring among the ISSH and the NSSH.
The common minke whale (Balaenoptera acutorostrata) is widely distributed in the North Atlantic a... more The common minke whale (Balaenoptera acutorostrata) is widely distributed in the North Atlantic and is frequently observed along the Icelandic, Norwegian and Portugal coasts, in eastern Canada, North Sea and Greenland, and around Jan Mayen and Svalbard islands. Traditionally, the management of the North Atlantic common minke whales has been based on four geographical subdivisions partitioned by the international Whaling Commission, namely the Canadian East coast stock, the West Greenland stock, the Central stock (Iceland) and the Northeastern stock (Norway). These management regions have been primarily established through studies based on catch statistics, biological characteristics and tagging. Lately, genetic studies tend to confirm the established subdivisions. The primary goal of the present study was to assess the genetic variation of North Atlantic common minke whales collected at different geographical regions using 16 microsatellite loci and mtDNA sequencing. Both genetic ma...
The appeal of genetic inference methods to assess population genetic structure and guide manageme... more The appeal of genetic inference methods to assess population genetic structure and guide management efforts is grounded in the correlation between the genetic similarity and gene flow among populations. Effects of such gene flow are typically genomewide; however, some loci may appear as outliers, displaying above or below average genetic divergence relative to the genomewide level. Above average population, genetic divergence may be due to divergent selection as a result of local adaptation. Consequently, substantial efforts have been directed toward such outlying loci in order to identify traits subject to local adaptation. Here, we report the results of an investigation into the molecular basis of the substantial degree of genetic divergence previously reported at allozyme loci among North Atlantic fin whale (Balaenoptera physalus) populations. We sequenced the exons encoding for the two most divergent allozyme loci (MDH-1 and MPI) and failed to detect any nonsynonymous substituti...
The spectral sensitivity of visual pigments in vertebrate eyes is optimized for specific light co... more The spectral sensitivity of visual pigments in vertebrate eyes is optimized for specific light conditions. One of such pigments, rhodopsin (RH1), mediates dim-light vision. Amino acid replacements at tuning sites may alter spectral sensitivity, providing a mechanism to adapt to ambient light conditions and depth of habitat in fish. Here we present a first investigation of RH1 gene polymorphism among two ecotypes of Atlantic cod in Icelandic waters, which experience divergent light environments throughout the year due to alternative foraging behaviour. We identified one synonymous single nucleotide polymorphism (SNP) in the RH1 protein coding region and one in the 3' untranslated region (3'-UTR) that are strongly divergent between these two ecotypes. Moreover, these polymorphisms coincided with the well-known panthophysin (Pan I) polymorphism that differentiates coastal and frontal (migratory) populations of Atlantic cod. While the RH1 SNPs do not provide direct inference for...
The main objective of this study was to confirm the level of genetic differentiation observed amo... more The main objective of this study was to confirm the level of genetic differentiation observed among samples of fin whale collected at feeding grounds using a new dataset composed of 500 selected individuals genotyped for 15 microsatellite loci and the mtDNA was sequenced. New methods of amplification have been used (especially for the microsatellite loci) to successfully genotyped these selected individuals. Both types of genetic markers employed revealed a lack of genetic differentiation among samples collected and therefore suggest that extensive gene flow might prevail among fin whale population and/or that a recent population expansion of the species occurred. The signal of population expansion detected with the mtDNA might suggest that population of fin whale are not at equilibrium and that further analyses based on this information should be carried out (calculation of potential time of expansion and divergence). However, the comparison of these results to the allozyme data th...
The main objective of this study was to confirm the level of genetic differentiation observed amo... more The main objective of this study was to confirm the level of genetic differentiation observed among samples of fin whale collected at feeding grounds using a new dataset composed of 500 selected individuals genotyped for 15 microsatellite loci and the mtDNA was sequenced. New methods of amplification have been used (especially for the microsatellite loci) to successfully genotyped these selected individuals. Both types of genetic markers employed revealed a lack of genetic differentiation among samples collected and therefore suggest that extensive gene flow might prevail among fin whale population and/or that a recent population expansion of the species occurred. The signal of population expansion detected with the mtDNA might suggest that population of fin whale are not at equilibrium and that further analyses based on this information should be carried out (calculation of potential time of expansion and divergence). However, the comparison of these results to the allozyme data th...
The paper presents results of new statistical analyses of three old fin whale allozyme and carbon... more The paper presents results of new statistical analyses of three old fin whale allozyme and carbonic anhydrase datasets previously published in Árnason et al. (1992) Daníelsdóttir et al. (1991b & 1992a). The first dataset is on the genetic variation at 11 variable allozyme loci in 328 fin whales (Balaenoptera physalus) sampled in two North Atlantic areas; i.e. off West Iceland and Spain, a total of: 283 (Iceland 1985, 1986, 1987 and 1988) and 46 (Spain 1985) samples, respectively. The data is based on further analysis of genotypes at 11 allozyme loci: Ada, Ak-1, Gpd, Ldh-A, Mdh-S, Mpi-1, Pep-A, Pgm-1, Pgi and Sod-A. The new statistical programs applied here include FST, Confidence Intervals (CI) of FST, Nm, PCA, MDS, STRUCTURE and graphical illustration of potential “populations” as in Waples and Gaggiotti (2006). There was significant heterogeneity within each sample and overall samples, all due to heterozygote deficiency. Various genetic analyses on the dataset resulted in signific...
ABSTRACT The genetic structure of Atlantic herring Clupea harengus L. was investigated in its nor... more ABSTRACT The genetic structure of Atlantic herring Clupea harengus L. was investigated in its north-easterly distribution in the Norwegian Sea and adjacent waters, using 23 neutral and one non-neutral (Cpa111) microsatellite loci. Fish from the suspected 2 main populations—the Norwegian spring-spawning herring (NSSH) and the Icelandic summer-spawning herring (ISSH)—were collected at spawning locations in their respective spawning seasons from 2009 to 2012. Samples were also collected from Norwegian autumn spawning locations, from different local Norwegian fjords such as the inner part of Trondheimsfjorden, Lindås pollene, Landvikvannet and Lusterfjorden, as well as from suspected Faroese spawning components. The observed level of genetic differentiation was significant but low (FST = 0.007) and mostly attributable to the differentiation of the local Norwegian fjord populations. The locus Cpa111, which was detected to putatively be under positive selection, exhibited the highest FST value (0.044). The observed genetic patterns were robust to exclusion of this locus. Landvikvannet herring was also genetically distinguishable from the 3 other fjord populations. In addition, the present study does not support genetic structuring among the ISSH and the NSSH.
The common minke whale (Balaenoptera acutorostrata) is widely distributed in the North Atlantic a... more The common minke whale (Balaenoptera acutorostrata) is widely distributed in the North Atlantic and is frequently observed along the Icelandic, Norwegian and Portugal coasts, in eastern Canada, North Sea and Greenland, and around Jan Mayen and Svalbard islands. Traditionally, the management of the North Atlantic common minke whales has been based on four geographical subdivisions partitioned by the international Whaling Commission, namely the Canadian East coast stock, the West Greenland stock, the Central stock (Iceland) and the Northeastern stock (Norway). These management regions have been primarily established through studies based on catch statistics, biological characteristics and tagging. Lately, genetic studies tend to confirm the established subdivisions. The primary goal of the present study was to assess the genetic variation of North Atlantic common minke whales collected at different geographical regions using 16 microsatellite loci and mtDNA sequencing. Both genetic ma...
The appeal of genetic inference methods to assess population genetic structure and guide manageme... more The appeal of genetic inference methods to assess population genetic structure and guide management efforts is grounded in the correlation between the genetic similarity and gene flow among populations. Effects of such gene flow are typically genomewide; however, some loci may appear as outliers, displaying above or below average genetic divergence relative to the genomewide level. Above average population, genetic divergence may be due to divergent selection as a result of local adaptation. Consequently, substantial efforts have been directed toward such outlying loci in order to identify traits subject to local adaptation. Here, we report the results of an investigation into the molecular basis of the substantial degree of genetic divergence previously reported at allozyme loci among North Atlantic fin whale (Balaenoptera physalus) populations. We sequenced the exons encoding for the two most divergent allozyme loci (MDH-1 and MPI) and failed to detect any nonsynonymous substituti...
The spectral sensitivity of visual pigments in vertebrate eyes is optimized for specific light co... more The spectral sensitivity of visual pigments in vertebrate eyes is optimized for specific light conditions. One of such pigments, rhodopsin (RH1), mediates dim-light vision. Amino acid replacements at tuning sites may alter spectral sensitivity, providing a mechanism to adapt to ambient light conditions and depth of habitat in fish. Here we present a first investigation of RH1 gene polymorphism among two ecotypes of Atlantic cod in Icelandic waters, which experience divergent light environments throughout the year due to alternative foraging behaviour. We identified one synonymous single nucleotide polymorphism (SNP) in the RH1 protein coding region and one in the 3' untranslated region (3'-UTR) that are strongly divergent between these two ecotypes. Moreover, these polymorphisms coincided with the well-known panthophysin (Pan I) polymorphism that differentiates coastal and frontal (migratory) populations of Atlantic cod. While the RH1 SNPs do not provide direct inference for...
The main objective of this study was to confirm the level of genetic differentiation observed amo... more The main objective of this study was to confirm the level of genetic differentiation observed among samples of fin whale collected at feeding grounds using a new dataset composed of 500 selected individuals genotyped for 15 microsatellite loci and the mtDNA was sequenced. New methods of amplification have been used (especially for the microsatellite loci) to successfully genotyped these selected individuals. Both types of genetic markers employed revealed a lack of genetic differentiation among samples collected and therefore suggest that extensive gene flow might prevail among fin whale population and/or that a recent population expansion of the species occurred. The signal of population expansion detected with the mtDNA might suggest that population of fin whale are not at equilibrium and that further analyses based on this information should be carried out (calculation of potential time of expansion and divergence). However, the comparison of these results to the allozyme data th...
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