scholarly journals Arctic-adapted dogs emerged at the Pleistocene–Holocene transition

Science ◽  
2020 ◽  
Vol 368 (6498) ◽  
pp. 1495-1499 ◽  
Author(s):  
Mikkel-Holger S. Sinding ◽  
Shyam Gopalakrishnan ◽  
Jazmín Ramos-Madrigal ◽  
Marc de Manuel ◽  
Vladimir V. Pitulko ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Similarity ◽  
Archaeological Evidence ◽  
Origin And Evolution ◽  
Sled Dogs ◽  
Sled Dog ◽  
Genomic Approach

Although sled dogs are one of the most specialized groups of dogs, their origin and evolution has received much less attention than many other dog groups. We applied a genomic approach to investigate their spatiotemporal emergence by sequencing the genomes of 10 modern Greenland sled dogs, an ~9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an ~33,000-year-old Siberian wolf. We found noteworthy genetic similarity between the ancient dog and modern sled dogs. We detected gene flow from Pleistocene Siberian wolves, but not modern American wolves, to present-day sled dogs. The results indicate that the major ancestry of modern sled dogs traces back to Siberia, where sled dog–specific haplotypes of genes that potentially relate to Arctic adaptation were established by 9500 years ago.

Conservation genetics and ecology of the endangered rainforest shrub, Triunia robusta, from the Sunshine Coast, Australia

2002 ◽  
Vol 50 (1) ◽  
pp. 93 ◽  
Author(s):  
Alison Shapcott
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Conservation Genetics ◽  
Population Size ◽  
Genetic Similarity ◽  
Small Region ◽  
Geographic Proximity ◽  
Close Proximity ◽  
The Mean

Triunia robusta, which until recently was thought to be extinct, is now classified nationally as endangered. It is an understorey species restricted to the subcoastal rainforests in a small region of the Sunshine Coast, Queensland. The project involved sampling the genetic variation and measuring the population size and size distribution of T. robusta and its geographically closest congener T. youngiana, which occurs further south and has a wider geographic distribution. A total of 877 T. robusta plants were recorded across the 11 populations, approximately half (56.8%) of these were juveniles less than 1 m tall, whereas in T. youngiana only about 36.4% of a population was composed of juveniles. Genetic diversity was similar but significantly higher for T. robusta than T. youngiana if the very small T. robusta populations (2 or 3 plants) were excluded from analysis (P < 0.05). The mean percentage of polymorphic loci among populations was high for both species. Triunia robusta is not, on average, more inbred than the more common T. youngiana. There was more differentiation between the T. robusta populations, which were in close proximity, than between the more geographically separated T. youngiana populations. Thus, there is evidence of more gene flow between populations of T. youngiana than between those of T. robusta. However, there was no geographic relationship between genetic similarity and geographic proximity in T. robusta

scholarly journals Population genomics data supports introgression between western Iberian Squalius freshwater fish species

2019 ◽  
Author(s):  
Sofia L. Mendes ◽  
Maria M. Coelho ◽  
Vitor C. Sousa
Keyword(s):  
Gene Flow ◽  
Freshwater Fish ◽  
Population Genomics ◽  
Genotyping By Sequencing ◽  
Population Divergence ◽  
Freshwater Species ◽  
Genomic Approach ◽  
Demographic Modelling ◽  
Paraphyletic Group ◽  
First Time

AbstractIn freshwater fish, processes of population divergence and speciation are often linked to the geomorphology of rivers and lakes that isolate populations. However, current geographical isolation does not necessarily imply total absence of gene flow during the divergence process. Here, we focused on four species of the genus Squalius in Portuguese rivers: S. carolitertii, S. pyrenaicus, S. aradensis and S. torgalensis. Previous studies based on eight nuclear and mitochondrial markers revealed incongruent patterns, with nuclear loci suggesting that S. pyrenaicus was a paraphyletic group since its northern populations were genetically closer to S. carolitertii than to its southern populations. For the first time, we successfully applied a genomic approach to the study of the relationship between these species, using a Genotyping by Sequencing (GBS) approach. Our results revealed a species tree with two main lineages: (i) S. carolitertii and S. pyrenaicus; (ii) S. torgalensis and S. aradensis. Regarding S. carolitertii and S. pyrenaicus, we found evidence for past introgression between the two in the northern part of S. pyrenaicus distribution. This introgression reconciles previous mitochondrial and nuclear incongruent results and explains the apparent paraphyly of S. pyrenaicus. Our demographic modelling estimates are consistent across models, suggesting that the northern populations of S. pyrenaicus received a contribution of approximately 90% from S. carolitertii and 10% from southern S. pyrenaicus. This illustrates that even in freshwater species currently allopatric, we are able to detect past gene flow events in present-day genomes, suggesting speciation is more complex than simply allopatric.

scholarly journals Description of breed ancestry and genetic health traits in arctic sled dog breeds

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Joseph A. Thorsrud ◽  
Heather J. Huson
Keyword(s):  
Principal Component ◽  
Factor Vii ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Genetic Characteristics ◽  
Dna Test ◽  
Sled Dogs ◽  
Sled Dog ◽  
Arctic Exploration ◽  
And Performance

Abstract Background This study describes the presence and frequency of health traits among three populations of dogs traditionally used for sledding and explores their ancestry and breed composition as provided by the commercially available Embark dog DNA test. The three populations include the purebred Siberian Husky and the admixed populations of Alaskan sled dogs and Polar Huskies. While the Siberian Husky represents a well-established breed with extensive historical and health data, the Alaskan sled dog is less studied but has been the subject of nutritional, physiological, and genetic studies related to ancestry and performance. In contrast, the Polar Husky is a relatively obscure and rare group of dogs used for arctic exploration with very little-known information. The three populations were compared using Embark results, providing new insight into the health traits circulating within the populations and the potential ancestral linkage of the health traits between the sledding populations. Embark results are based upon 228,588 single-nucleotide polymorphisms (SNPs) spanning the canine genome, characterized using a custom-designed Illumina beadchip array. Results Specifically, breed composition was summarized for the two admixed populations with most of the dogs being predominantly categorized as Alaskan husky- type dog or “Supermutt”. Mitochondrial and Y chromosome haplogroups and haplotypes were found with Alaskan sled dogs carrying most of the haplogroups and types found in Siberian and Polar Huskies. Genomic principal component analysis reflected population structure corresponding to breed and substructure within the Alaskan sled dogs related to sprint or distance competition. Genetic markers associated with Alanine Aminotransferase activity, Alaskan Husky Encephalopathy, dilated cardiomyopathy, Collie eye anomaly, degenerative myelopathy, ichthyosis, and factor VII deficiency were identified in the populations of sledding breeds. Conclusion These results provide a preliminary description of genetic characteristics found in sledding breeds, improving the understanding and care of working sled dogs.

scholarly journals Visualizing spatial population structure with estimated effective migration surfaces

2014 ◽  
Author(s):  
Desislava Petkova ◽  
John Novembre ◽  
Matthew Stephens
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Genetic Similarity ◽  
Large Scale ◽  
Genetic Model ◽  
Isolation By Distance ◽  
Genetic Data ◽  
Migration Rates ◽  
Spatial Population ◽  
Spatial Population Structure

Genetic data often exhibit patterns that are broadly consistent with "isolation by distance" - a phenomenon where genetic similarity tends to decay with geographic distance. In a heterogeneous habitat, decay may occur more quickly in some regions than others: for example, barriers to gene flow can accelerate the genetic differentiation between groups located close in space. We use the concept of "effective migration" to model the relationship between genetics and geography: in this paradigm, effective migration is low in regions where genetic similarity decays quickly. We present a method to quantify and visualize variation in effective migration across the habitat, which can be used to identify potential barriers to gene flow, from geographically indexed large-scale genetic data. Our approach uses a population genetic model to relate underlying migration rates to expected pairwise genetic dissimilarities, and estimates migration rates by matching these expectations to the observed dissimilarities. We illustrate the potential and limitations of our method using simulations and data from elephant, human, and Arabidopsis thaliana populations. The resulting visualizations highlight important features of the spatial population structure that are difficult to discern using existing methods for summarizing genetic variation such as principal components analysis.

scholarly journals Pre- and Post-Race Intestinal Microbiota in Long-Distance Sled Dogs and Associations with Performance

Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 204 ◽  
Author(s):  
Kristoffer Relling Tysnes ◽  
Inga Leena Angell ◽  
Iselin Fjellanger ◽  
Sigrid Drageset Larsen ◽  
Silje Rebekka Søfteland ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Compositional Data ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Long Distance ◽  
Associated Bacteria ◽  
Sled Dogs ◽  
Sled Dog ◽  
Strong Negative Association ◽  
Rrna Gene Sequencing

Although our understanding of the role of the gut microbiota in different diseases is improving, our knowledge regarding how the gut microbiota affects functioning in healthy individuals is still limited. Here, we hypothesize that the gut microbiota could be associated with sled dog endurance-race performance. We investigated the gut microbiota in 166 fecal samples from 96 Alaskan Huskies, representing 16 teams participating in the 2016 Femund Race (400 km) in Norway, relating the microbiota composition to performance and metadata derived from questionnaires. For 16S rRNA gene sequencing-derived compositional data, we found a strong negative association between Enterobacteriaceae (dysbiosis-associated) and Clostridium hiranonis (normobiosis-associated). The teams with the best performances showed both the lowest levels of dysbiosis-associated bacteria prior to the race and the lowest change (decrease) in these bacteria after the race. Taken together, our results support the hypothesis that normobiosis-associated bacteria are involved in resilience mechanisms, potentially preventing growth of Enterobacteriaceae during the race.

scholarly journals A spatial genomic approach identifies time lags and historical barriers to gene flow in a rapidly fragmenting Appalachian landscape

2020 ◽  
Vol 29 (4) ◽  
pp. 673-685 ◽  
Author(s):  
Thomas A. Maigret ◽  
John J. Cox ◽  
David W. Weisrock
Keyword(s):  
Gene Flow ◽  
Time Lags ◽  
Genomic Approach

scholarly journals Exercise-associated hyponatremia in Alaskan sled dogs: urinary and hormonal responses

1997 ◽  
Vol 83 (3) ◽  
pp. 824-829 ◽  
Author(s):  
K. W. Hinchcliff ◽  
G. A. Reinhart ◽  
J. R. Burr ◽  
R. A. Swenson
Keyword(s):  
Plasma Concentrations ◽  
Plasma Renin ◽  
Urine Osmolality ◽  
Sodium Concentration ◽  
Serum Electrolyte ◽  
Water Turnover ◽  
Hormonal Responses ◽  
Sled Dogs ◽  
Sled Dog ◽  
Group Water

Hinchcliff, K. W., G. A. Reinhart, J. R. Burr, R. A. Swenson. Exercise-associated hyponatremia in Alaskan sled dogs: urinary and hormonal responses. J. Appl. Physiol. 83(3): 824–829, 1997.—Exercise-associated hyponatremia occurs in horses and humans, both species that sweat, and in sled dogs, which do not sweat. To investigate the mechanism of exercise-associated hyponatremia in sled dogs, we measured water turnover, serum electrolyte concentrations and osmolality, plasma renal hormone concentrations, and urine composition of 12 fit Alaskan sled dogs before, during, and after a 490-km sled dog race (Ex group). Water turnover and serum electrolyte concentrations were measured in six similarly fit dogs that did not run (Sed group). Water turnover was significantly larger ( P < 0.001) in Ex [190 ± 19 (SD) ml ⋅ kg−1 ⋅ day−1] than in Sed dogs (51 ± 13 ml ⋅ kg−1 ⋅ day−1). There were significant ( P < 0.001) decreases in serum sodium concentration (from 148.6 ± 2.8 to 139.7 ± 1.9 mmol/l) and osmolality (from 306 ± 9 to 296 ± 5 mosmol/kgH2O) of Ex, but not Sed, dogs during the race. Plasma concentrations of arginine vasopressin decreased, whereas aldosterone and plasma renin activity increased significantly ( P < 0.01) during the race. Urine osmolality was unchanged, whereas urine sodium, potassium, and chloride concentrations decreased significantly ( P < 0.05) and urine urea concentration increased ( P = 0.06). These results demonstrate increased water turnover associated with hyponatremia and renal sodium conservation with maintained high urine osmolality in exercising Alaskan sled dogs.

scholarly journals Crossing the impassable: genetic connections in 20 reef fishes across the eastern Pacific barrier

2006 ◽  
Vol 273 (1598) ◽  
pp. 2201-2208 ◽  
Author(s):  
H.A Lessios ◽  
D.R Robertson
Keyword(s):  
Gene Flow ◽  
Genetic Similarity ◽  
Reef Fishes ◽  
Eastern Pacific ◽  
Cryptic Speciation ◽  
Central Pacific ◽  
Species Migration ◽  
Initial Separation ◽  
Haplotype Networks ◽  
Biogeographic Barrier

The ‘impassable’ Eastern Pacific Barrier (EPB), ca 5000 km of deep water separating the eastern from the central Pacific, is the World's widest marine biogeographic barrier. Sequencing of mitochondrial DNA in 20 reef fish morphospecies encountered on both sides of the barrier revealed cryptic speciation in two. Among the other 18 species only two showed significant differentiation (as revealed by haplotype networks and F ST statistics) between the eastern and the central Pacific. Coalescence analyses indicated that genetic similarity in the 18 truly transpacific species resulted from different combinations of ages of most recent invasion and of levels of recurrent gene flow, with estimated times of initial separation ranging from approximately 30 000 to 1 Myr (ago). There is no suggestion of simultaneous interruptions of gene flow among the species. Migration across the EPB was previously thought to be exclusively eastward, but our evidence showed two invasions from east to west and eight cases in which subsequent gene flow possibly proceeded in the same direction. Thus, the EPB is sporadically permeable to propagules originating on either side.

scholarly journals Diversitatea moleculară a două ecotipuri de Datura inoxia provenite din vestul şi estul României

2020 ◽  
Author(s):  
Cristina Chelu ◽  
◽  
Carmen Varlam ◽  
Gheorghe Titescu ◽  
Gallia Butnaru ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Genetic Similarity ◽  
Molecular Diversity ◽  
Rapd Analysis ◽  
Genomic Variation ◽  
Origin And Evolution ◽  
Random Primers ◽  
Datura Inoxia

Molecular Diversity of two Ecotypes of Datura inoxia Originating from Western and Eastern Romania. To characterize genomic variation among genotypes, we have performed RAPD analysis using ten random primers. The results yielded 88 bands out of which 39 were polymorphic. The primers US1 and US7 showed 87.71% and 72.72% polymorphism respectively. The least polymorphism was shown by primer US9 (12.50%). The primer US15 did not produce any bands suggesting the absence of matching sequences in the genomic DNA. The dendrogram classified ecotypes into two clusters (A and B); cluster B possess three sub-clusters: B1 - Socodor 2; B2 - Flamura 1 and Flamura 2, and B3 - Flamura 3. Overall, the values of genetic similarity between ecotypes were low pointing out their particular origin and “evolution”.

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