Capture and long-distance translocation of cleaner fish to control lice infestations on marine sa... more Capture and long-distance translocation of cleaner fish to control lice infestations on marine salmonid farms has the potential to influence wild populations via overexploitation in source regions, and introgression in recipient regions. Knowledge of population genetic structure is therefore required. We studied the genetics of ballan wrasse, a phenotypically diverse and extensively used cleaner fish, from 18 locations in Norway and Sweden, and from Galicia, Spain. We detected two very distinct genetic groups in Scandinavia, northwest and southeast. These groups were split by a stretch of sandy beaches in southwest Norway, representing a habitat discontinuity for this rocky shore associated benthic egg laying species. The Galician sample was highly differentiated from all Scandinavian samples, but overall closer to northwestern samples. . Distinct genetic differences were observed between sympatric spotty and plain phenotypes in Galicia, but not in Scandinavia. The mechanisms underl...
Table containing the phenotypic data from the common garden experiment for the 126 families used ... more Table containing the phenotypic data from the common garden experiment for the 126 families used in this study. Mass at metamorphosis is given in g, larval period in days
Genepop formatted file containing genotypes from the 1000 putatively neutral SNPs for 136 individ... more Genepop formatted file containing genotypes from the 1000 putatively neutral SNPs for 136 individuals. SNP names are ddRAD fragment_SNP position. Data are organized in the five regions, each comprising individuals from 3 populations, as given in Table S1 of the publication. Populations have been renamed for the publications (A=L1 in the publication, L=L2, M=L3, R=S1, S=S2, T=S3, C=U1, O=U2, V=U3, H=V1, N=V2, U=V3, B=N1, E=N2, G=N3), individuals are named by population_family-tadpole, i.e. M3-2 is the second tadpole of family 3 of population M
Ectotherm development rates often show adaptive divergence along climatic gradients, but the gene... more Ectotherm development rates often show adaptive divergence along climatic gradients, but the genetic basis for this variation is rarely studied. Here, we investigated the genetic basis for phenotypic variation in larval development in the moor frog Rana arvalis from five regions along a latitudinal gradient from Germany to northern Sweden. We focused on the C/EBP-1 gene, a transcription factor associated with larval development time. Allele frequencies at C/EBP-1 varied strongly among geographic regions. Overall, the distribution of alleles along the gradient was in concordance with the dual postglacial colonization routes into Scandinavia, with a large number of alleles exclusively present along the southern colonization route. Only three of 38 alleles were shared between the routes. Analysis of contemporary selection on C/EBP-1 showed divergent selection among the regions, likely reflecting adaptation to the local environmental conditions, although this was especially strong between southern and northern regions coinciding also with lineages from different colonization routes. Overall, the C/EBP-1 gene has historically been under purifying selection, however, two specific amino acid positions showed significant signals of positive selection. These positions showed divergence between southern and northern regions, and we suggest that they are functionally involved in the climatic adaptation of larval development. Using phenotypic data from a common garden experiment, we found evidence for specific C/EBP-1 alleles being correlated with larval development time, suggesting a functional role in adaptation of larval development to large-scale climatic variation
In the marine environment, where there are few absolute physical barriers, contemporary contact b... more In the marine environment, where there are few absolute physical barriers, contemporary contact between previously isolated species can occur across great distances, and in some cases, may be inter-oceanic. An example of this can be seen in the minke whale species complex. Antarctic minke whales are genetically and morphologically distinct from the common minke found in the north Atlantic and Pacific oceans, and the two species are estimated to have been isolated from each other for 5 million years or more. Recent atypical migrations from the southern to the northern hemisphere have been documented and fertile hybrids and back-crossed individuals between both species have also been identified. However, it is not known whether this represents a contemporary event, potentially driven by ecosystem changes in the Antarctic, or a sporadic occurrence happening over an evolutionary time-scale. We successfully used whole genome resequencing to identify a panel of diagnostic SNPs which now e...
Temperature is one of the most influential forces of natural selection impacting all biological l... more Temperature is one of the most influential forces of natural selection impacting all biological levels. In the face of increasing global temperatures, studies over small geographical scales allowing investigations on the effects of gene flow are of great value for understanding thermal adaptation. Here we investigated genetic population structure in the freshwater gastropod Radix balthica originating from contrasting thermal habitats in three areas of geothermal activity in Iceland. Snails from 32 sites were genotyped at 208 AFLP loci. Five AFLPs were identified as putatively under divergent selection in Lake Mývatn, a geothermal lake with an almost 20 °C difference in mean temperature across a distance of a few kilometers. In four of these loci, variation across all study populations was correlated with temperature. We found significant population structure in neutral markers both within and between the areas. Cluster analysis using neutral markers classified the sites mainly by ge...
The ballan wrasse, Labrus bergylta is a marine fish belonging to the family Labridae characterise... more The ballan wrasse, Labrus bergylta is a marine fish belonging to the family Labridae characterised by two main morphotypes that occur in sympatry: spotty and plain. Previous studies have revealed differences in their life-history traits such as growth and maturation; however, the genetic relationship between forms is presently unknown. Using twenty recently developed microsatellite markers, we conducted a genetic analysis of 41 and 48 spotty and plain ballan wrasse collected in Galicia (NW Spain). The two morphotypes displayed highly significant genetic differences to each other (FST = 0.018, P<0.0001). A similar degree of genetic differentiation (FST = 0.025, P<0.0001) was shown using STRUCTURE clustering approach with no priors at K = 2. In this case, the frequency of spotty and plain morphotypes was significantly different (x(2) = 9.46, P = 0.002). It is concluded that there is significant genetic heterogeneity within this species, which appears to be highly associated with...
Capture and long-distance translocation of cleaner fish to control lice infestations on marine sa... more Capture and long-distance translocation of cleaner fish to control lice infestations on marine salmonid farms has the potential to influence wild populations via overexploitation in source regions, and introgression in recipient regions. Knowledge of population genetic structure is therefore required. We studied the genetics of ballan wrasse, a phenotypically diverse and extensively used cleaner fish, from 18 locations in Norway and Sweden, and from Galicia, Spain. We detected two very distinct genetic groups in Scandinavia, northwest and southeast. These groups were split by a stretch of sandy beaches in southwest Norway, representing a habitat discontinuity for this rocky shore associated benthic egg laying species. The Galician sample was highly differentiated from all Scandinavian samples, but overall closer to northwestern samples. . Distinct genetic differences were observed between sympatric spotty and plain phenotypes in Galicia, but not in Scandinavia. The mechanisms underl...
Table containing the phenotypic data from the common garden experiment for the 126 families used ... more Table containing the phenotypic data from the common garden experiment for the 126 families used in this study. Mass at metamorphosis is given in g, larval period in days
Genepop formatted file containing genotypes from the 1000 putatively neutral SNPs for 136 individ... more Genepop formatted file containing genotypes from the 1000 putatively neutral SNPs for 136 individuals. SNP names are ddRAD fragment_SNP position. Data are organized in the five regions, each comprising individuals from 3 populations, as given in Table S1 of the publication. Populations have been renamed for the publications (A=L1 in the publication, L=L2, M=L3, R=S1, S=S2, T=S3, C=U1, O=U2, V=U3, H=V1, N=V2, U=V3, B=N1, E=N2, G=N3), individuals are named by population_family-tadpole, i.e. M3-2 is the second tadpole of family 3 of population M
Ectotherm development rates often show adaptive divergence along climatic gradients, but the gene... more Ectotherm development rates often show adaptive divergence along climatic gradients, but the genetic basis for this variation is rarely studied. Here, we investigated the genetic basis for phenotypic variation in larval development in the moor frog Rana arvalis from five regions along a latitudinal gradient from Germany to northern Sweden. We focused on the C/EBP-1 gene, a transcription factor associated with larval development time. Allele frequencies at C/EBP-1 varied strongly among geographic regions. Overall, the distribution of alleles along the gradient was in concordance with the dual postglacial colonization routes into Scandinavia, with a large number of alleles exclusively present along the southern colonization route. Only three of 38 alleles were shared between the routes. Analysis of contemporary selection on C/EBP-1 showed divergent selection among the regions, likely reflecting adaptation to the local environmental conditions, although this was especially strong between southern and northern regions coinciding also with lineages from different colonization routes. Overall, the C/EBP-1 gene has historically been under purifying selection, however, two specific amino acid positions showed significant signals of positive selection. These positions showed divergence between southern and northern regions, and we suggest that they are functionally involved in the climatic adaptation of larval development. Using phenotypic data from a common garden experiment, we found evidence for specific C/EBP-1 alleles being correlated with larval development time, suggesting a functional role in adaptation of larval development to large-scale climatic variation
In the marine environment, where there are few absolute physical barriers, contemporary contact b... more In the marine environment, where there are few absolute physical barriers, contemporary contact between previously isolated species can occur across great distances, and in some cases, may be inter-oceanic. An example of this can be seen in the minke whale species complex. Antarctic minke whales are genetically and morphologically distinct from the common minke found in the north Atlantic and Pacific oceans, and the two species are estimated to have been isolated from each other for 5 million years or more. Recent atypical migrations from the southern to the northern hemisphere have been documented and fertile hybrids and back-crossed individuals between both species have also been identified. However, it is not known whether this represents a contemporary event, potentially driven by ecosystem changes in the Antarctic, or a sporadic occurrence happening over an evolutionary time-scale. We successfully used whole genome resequencing to identify a panel of diagnostic SNPs which now e...
Temperature is one of the most influential forces of natural selection impacting all biological l... more Temperature is one of the most influential forces of natural selection impacting all biological levels. In the face of increasing global temperatures, studies over small geographical scales allowing investigations on the effects of gene flow are of great value for understanding thermal adaptation. Here we investigated genetic population structure in the freshwater gastropod Radix balthica originating from contrasting thermal habitats in three areas of geothermal activity in Iceland. Snails from 32 sites were genotyped at 208 AFLP loci. Five AFLPs were identified as putatively under divergent selection in Lake Mývatn, a geothermal lake with an almost 20 °C difference in mean temperature across a distance of a few kilometers. In four of these loci, variation across all study populations was correlated with temperature. We found significant population structure in neutral markers both within and between the areas. Cluster analysis using neutral markers classified the sites mainly by ge...
The ballan wrasse, Labrus bergylta is a marine fish belonging to the family Labridae characterise... more The ballan wrasse, Labrus bergylta is a marine fish belonging to the family Labridae characterised by two main morphotypes that occur in sympatry: spotty and plain. Previous studies have revealed differences in their life-history traits such as growth and maturation; however, the genetic relationship between forms is presently unknown. Using twenty recently developed microsatellite markers, we conducted a genetic analysis of 41 and 48 spotty and plain ballan wrasse collected in Galicia (NW Spain). The two morphotypes displayed highly significant genetic differences to each other (FST = 0.018, P<0.0001). A similar degree of genetic differentiation (FST = 0.025, P<0.0001) was shown using STRUCTURE clustering approach with no priors at K = 2. In this case, the frequency of spotty and plain morphotypes was significantly different (x(2) = 9.46, P = 0.002). It is concluded that there is significant genetic heterogeneity within this species, which appears to be highly associated with...
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Papers by Maria Quintela