scholarly journals Genomes reveal genetic diversity of Piscine orthoreovirus in farmed and free-ranging salmonids from Canada and USA

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
A Siah ◽  
R B Breyta ◽  
K I Warheit ◽  
N Gagne ◽  
M K Purcell ◽  
...  

Abstract Piscine orthoreovirus (PRV-1) is a segmented RNA virus, which is commonly found in salmonids in the Atlantic and Pacific Oceans. PRV-1 causes the heart and skeletal muscle inflammation disease in Atlantic salmon and is associated with several other disease conditions. Previous phylogenetic studies of genome segment 1 (S1) identified four main genogroups of PRV-1 (S1 genogroups I–IV). The goal of the present study was to use Bayesian phylogenetic inference to expand our understanding of the spatial, temporal, and host patterns of PRV-1 from the waters of the northeast Pacific. To that end, we determined the coding genome sequences of fourteen PRV-1 samples that were selected to improve our knowledge of genetic diversity across a broader temporal, geographic, and host range, including the first reported genome sequences from the northwest Atlantic (Eastern Canada). Nucleotide and amino acid sequences of the concatenated genomes and their individual segments revealed that established sequences from the northeast Pacific were monophyletic in all analyses. Bayesian inference phylogenetic trees of S1 sequences using BEAST and MrBayes also found that sequences from the northeast Pacific grouped separately from sequences from other areas. One PRV-1 sample (WCAN_BC17_AS_2017) from an escaped Atlantic salmon, collected in British Columbia but derived from Icelandic broodstock, grouped with other S1 sequences from Iceland. Our concatenated genome and S1 analysis demonstrated that PRV-1 from the northeast Pacific is genetically distinct but descended from PRV-1 from the North Atlantic. However, the analyses were inconclusive as to the timing and exact source of introduction into the northeast Pacific, either from eastern North America or from European waters of the North Atlantic. There was no evidence that PRV-1 was evolving differently between free-ranging Pacific Salmon and farmed Atlantic Salmon. The northeast Pacific PRV-1 sequences fall within genogroup II based on the classification of Garseth, Ekrem, and Biering (Garseth, A. H., Ekrem, T., and Biering, E. (2013) ‘Phylogenetic Evidence of Long Distance Dispersal and Transmission of Piscine Reovirus (PRV) between Farmed and Wild Atlantic Salmon’, PLoS One, 8: e82202.), which also includes North Atlantic sequences from Eastern Canada, Iceland, and Norway. The additional full-genome sequences herein strengthen our understanding of phylogeographical patterns related to the northeast Pacific, but a more balanced representation of full PRV-1 genomes from across its range, as well additional sequencing of archived samples, is still needed to better understand global relationships including potential transmission links among regions.

2007 ◽  
Vol 64 (2) ◽  
pp. 394-404 ◽  
Author(s):  
Aaron D. Spares ◽  
Jeffery M. Reader ◽  
Michael J. W. Stokesbury ◽  
Tom McDermott ◽  
Lubomir Zikovsky ◽  
...  

AbstractSpares, A.D., Reader, J.M., Stokesbury, M.J.W., McDermott, T., Zikovsky, L., Avery, T.S., and Dadswell, M.J. 2007. Inferring marine distribution of Canadian and Irish Atlantic salmon (Salmo salar L.) in the North Atlantic from tissue concentrations of bio-accumulated caesium 137. – ICES Journal of Marine Science, 64: 394–404. Atlantic salmon returning from marine migrations to eastern Canada and western Ireland during 2002 and 2003 were analysed for tissue concentrations of bio-accumulated caesium 137 (137Cs). Salmon from Canadian and Irish waters demonstrated concentrations (0.20 ± 0.14 Bq kg−1 and 0.19 ± 0.09 Bq kg−1, mean ± s.d., respectively) suggesting similar oceanic feeding distributions during migration. Canadian aquaculture escapees had a similar mean tissue concentration (0.28 ± 0.22 Bq kg−1), suggesting migration with wild salmon. However, significantly higher concentrations in 1-sea-winter (1SW) escapees (0.43 ± 0.25 Bq kg−1) may alternatively suggest feeding within local estuaries. High concentrations in some Canadian 1SW salmon indicated trans-Atlantic migration. Low concentrations of Canadian multi-sea-winter (MSW) salmon suggested a feeding distribution in the Labrador and Irminger Seas before homeward migration, because those regions have the lowest surface water 137Cs levels. Estimates of wild Canadian and Irish salmon feeding east of the Faroes (∼8°W) were 14.2% and 10.0% (1SW, 24.7% and 11.5%; MSW, 2.9% and 0.0%), respectively. We propose that most anadromous North Atlantic salmon utilize the North Atlantic Gyre for marine migration and should be classified as a single trans-Atlantic straddling stock.


2020 ◽  
Vol 77 (11) ◽  
pp. 1846-1852
Author(s):  
David Minkoff ◽  
Nathan F. Putman ◽  
Jelle Atema ◽  
William R. Ardren

Many animals undertaking long-distance migrations use Earth’s magnetic field as a “map” to assess their position for orientation. This phenomenon been particularly well-studied in salmonids using “magnetic displacement” experiments, in which animals are presented with magnetic field conditions that are characteristic of other geographic locations. However, whether use of magnetic map cues differs among populations of salmon has not been investigated. Here we show that nonanadromous and anadromous populations of Atlantic salmon (Salmo salar) raised under the same conditions within their native range differ in their response to magnetic displacements in the North Atlantic. The directions adopted by anadromous salmon juveniles to each of the magnetic displacements would support their migration from the eastern US to western Greenland, had the fish actually been at those locations. In contrast, nonanadromous salmon did not appear to respond to the magnetic displacements. The findings are consistent with the hypothesis that the innate magnetic map of anadromous salmon is adapted to guide their marine migration.


2004 ◽  
Vol 61 (7) ◽  
pp. 1176-1190 ◽  
Author(s):  
C D Todd ◽  
A M Walker ◽  
M G Ritchie ◽  
J A Graves ◽  
A F Walker

The copepod Lepeophtheirus salmonis is ectoparasitic on Atlantic and Pacific wild salmonids. It is a major pest to Atlantic salmon (Salmo salar) aquaculture and may be implicated in recent declines of certain European wild salmonid stocks. Variation at six microsatellite loci was assessed among L. salmonis from wild and farmed salmonids in Scotland, wild sea-run brown trout (Salmo trutta) in Norway, and farmed Atlantic salmon in eastern Canada. An outgroup North Pacific sample was obtained from farmed Atlantic salmon in British Columbia. No significant differentiation was found between L. salmonis from the host species or among samples from throughout the North Atlantic. This is consistent with long-distance oceanic migration of wild hosts and larval interchange between farmed and wild host stocks being sufficient to prevent genetic divergence of L. salmonis throughout the North Atlantic. These results have important management implications for both wild stock conservation and aquaculture in that genetically, L. salmonis in the North Atlantic comprises a single population: there is no evidence of isolation of populations on farmed hosts from those on wild fish. Comparison between North Pacific and North Atlantic L. salmonis populations showed significant but low differentiation (FST = 0.06).


Author(s):  
Peter S. Wells ◽  
Naoise Mac Sweeney

Iron Age Europe, once studied as a relatively closed, coherent continent, is being seen increasingly as a dynamic part of the much larger, interconnected world. Interactions, direct and indirect, with communities in Asia, Africa, and, by the end of the first millennium AD, North America, had significant effects on the peoples of Iron Age Europe. In the Near East and Egypt, and much later in the North Atlantic, the interactions can be linked directly to historically documented peoples and their rulers, while in temperate Europe the evidence is exclusively archaeological until the very end of the prehistoric Iron Age. The evidence attests to often long-distance interactions and their effects in regard to the movement of peoples, and the introduction into Europe of raw materials, crafted objects, styles, motifs, and cultural practices, as well as the ideas that accompanied them.


2017 ◽  
Vol 30 (24) ◽  
pp. 10259-10274 ◽  
Author(s):  
Xin Tan ◽  
Ming Bao ◽  
Dennis L. Hartmann ◽  
Paulo Ceppi

Previous studies have demonstrated that the NAO, the leading mode of atmospheric low-frequency variability over the North Atlantic, could be linked to northeast Pacific climate variability via the downstream propagation of synoptic waves. In those studies, the NAO and the northeast Pacific climate variability are considered as two separate modes that explain the variance over the North Atlantic sector and the east Pacific–North American sector, respectively. A newly identified low-frequency atmospheric regime—the Western Hemisphere (WH) circulation pattern—provides a unique example of a mode of variability that accounts for variance over the whole North Atlantic–North American–North Pacific sector. The role of synoptic waves in the formation and maintenance of the WH pattern is investigated using the ECMWF reanalysis datasets. Persistent WH events are characterized by the propagation of quasi-stationary Rossby waves across the North Pacific–North American–North Atlantic regions and by associated storm-track anomalies. The eddy-induced low-frequency height anomalies maintain the anomalous low-frequency ridge over the Gulf of Alaska, which induces more equatorward propagation of synoptic waves on its downstream side. The eddy forcing favors the strengthening of the midlatitude jet and the deepening of the mid-to-high-latitude trough over the North Atlantic, whereas the deepening of the trough over eastern North America mostly arises from the quasi-stationary waves propagating from the North Pacific. A case study for the 2013/14 winter is examined to illustrate the downstream development of synoptic waves. The roles of synoptic waves in the formation and maintenance of the WH pattern and in linking the northeast Pacific ridge anomaly with the NAO are discussed.


1991 ◽  
Vol 220 (4) ◽  
pp. 829-830
Author(s):  
Rolf L. Larsen ◽  
Asbjørn Hordvik ◽  
Edward Hough ◽  
Knut Jynge ◽  
Lars Kr. Hansen

1990 ◽  
Vol 214 (2) ◽  
pp. 355-358 ◽  
Author(s):  
Arne O. Smal Ås ◽  
Asbjørn Hordvik ◽  
Lars Kr. Hansen ◽  
Edward Hough ◽  
Knut Jynge

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