A genomic‐based vision on the genetic diversity and key performance traits in selectively bred Arctic charr ( Salvelinus alpinus )

Incorporation of genomic technologies into fish breeding programs is a modern reality, promising substantial advances regarding the accuracy of selection, monitoring the genetic diversity and pedigree record verification. Single nucleotide polymorphism (SNP) arrays are the most commonly used genomic tool, but the investments required make them unsustainable for emerging species, such as Arctic charr (Salvelinus alpinus), where production volume is low. The requirement to genotype a large number of animals for breeding practices necessitates cost effective genotyping approaches. In the current study, we used double digest restriction site-associated DNA (ddRAD) sequencing of either high or low coverage to genotype Arctic charr from the Swedish national breeding program and performed analytical procedures to assess their utility in a range of tasks. SNPs were identified and used for deciphering the genetic structure of the studied population, estimating genomic relationships and implementing an association study for growth-related traits. Missing information and underestimation of heterozygosity in the low coverage set were limiting factors in genetic diversity and genomic relationship analyses, where high coverage performed notably better. On the other hand, the high coverage dataset proved to be valuable when it comes to identifying loci that are associated with phenotypic traits of interest. In general, both genotyping strategies offer sustainable alternatives to hybridization-based genotyping platforms and show potential for applications in aquaculture selective breeding.

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Genetic insights into the management and conservation of Arctic charr in North Wales

10.1101/2021.12.03.470319 ◽

2021 ◽

Author(s):

Samantha V. Beck ◽

Gary R. Carvalho ◽

Ian McCarthy ◽

Walter Hanks ◽

Robert Evans ◽

...

Keyword(s):

Genetic Diversity ◽

Salvelinus Alpinus ◽

Arctic Charr ◽

Long Term Effects ◽

Effective Population ◽

Isolated Populations ◽

Anthropogenic Pressures ◽

Southern Limit ◽

North Wales ◽

Native Populations

AbstractAquatic species throughout the world are threatened by extinction in many parts of their range, particularly in their most southerly distributions. Arctic charr (Salvelinus alpinus) is a Holarctic species with a distribution that includes the glacial lakes of North Wales, towards it southern limit. To date, no genetic studies have been conducted to determine the genetic health of the three remaining native Arctic charr populations in North Wales, despite exposure to stocking and adverse environmental and ecological conditions. We used seven microsatellite loci to determine whether: 1) genetic differentiation existed between native populations; 2) translocated populations from Llyn Peris were genetically similar to the historically connected Llyn Padarn population; and 3) hatchery supplementation negatively impacted genetic diversity in Llyn Padarn. All three native populations retained their genetic integrity, with Llyn Bodlyn showing high levels of divergence (FST = 0.26 ± 0.02SD) as well as low genetic diversity (HO 0.30) compared to remaining populations (HO 0.64 ± 0.14SD). Although evidence suggests that stocking increased the effective population size of Llyn Padarn in the short term without impacting genetic diversity, the long term effects of such practices are yet to be seen. Results provide baseline data for conservation management, and highlight the need for protection of small isolated populations that are being negatively impacted by the processes of genetic drift due to escalating anthropogenic pressures. Continual monitoring of both Arctic charr and their habitats using a combination of methods will increase the likelihood that these threatened and iconic populations will persist in the future.

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Impaired Swimming Performance of Acid-exposed Arctic Charr, Salvelinus Alpinus L.

Water Quality Research Journal ◽

10.2166/wqrj.1988.021 ◽

1988 ◽

Vol 23 (2) ◽

pp. 301-307 ◽

Cited By ~ 2

Author(s):

L.A. Hunter ◽

E. Scherer

Keyword(s):

Dose Response ◽

Salvelinus Alpinus ◽

Arctic Charr ◽

Swimming Performance ◽

Control Level ◽

Ventilation Rates

Abstract Arctic charr (Salvelinus alpinus L.) were exposed to five levels of acidity between pH 6 and pH 3.8. Swimming performance as determined by critical swimming speeds was 67.5 cm · sࢤ1 or 4.4 body lengths per second for untreated fish (pH 7.8). Performance declined sharply below pH 4.5; at pH 3.8 it was reduced by 35% after 7 days of exposure. Tailbeat frequencies and ventilation rates showed no dose-response effects. At swimming speeds between 20 and 50 cm · sࢤ1, ventilation rates at all levels of acidity were higher than at the control level.

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