La Rochelle, France


La Rochelle, France
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Ellis J.S.,University of Exeter | Gilbey J.,Marine Scotland - Marine Laboratory | Armstrong A.,Marine Scotland - Marine Laboratory | Balstad T.,Norwegian Institute for Nature Research | And 26 more authors.
Genetica | Year: 2011

Microsatellite genotyping is a common DNA characterization technique in population, ecological and evolutionary genetics research. Since different alleles are sized relative to internal size-standards, different laboratories must calibrate and standardize allelic designations when exchanging data. This interchange of microsatellite data can often prove problematic. Here, 16 microsatellite loci were calibrated and standardized for the Atlantic salmon, Salmo salar, across 12 laboratories. Although inconsistencies were observed, particularly due to differences between migration of DNA fragments and actual allelic size ('size shifts'), inter-laboratory calibration was successful. Standardization also allowed an assessment of the degree and partitioning of genotyping error. Notably, the global allelic error rate was reduced from 0.05 ± 0.01 prior to calibration to 0.01 ± 0.002 post-calibration. Most errors were found to occur during analysis (i. e. when size-calling alleles; the mean proportion of all errors that were analytical errors across loci was 0.58 after calibration). No evidence was found of an association between the degree of error and allelic size range of a locus, number of alleles, nor repeat type, nor was there evidence that genotyping errors were more prevalent when a laboratory analyzed samples outside of the usual geographic area they encounter. The microsatellite calibration between laboratories presented here will be especially important for genetic assignment of marine-caught Atlantic salmon, enabling analysis of marine mortality, a major factor in the observed declines of this highly valued species. © 2011 The Author(s).

Perrier C.,French National Institute for Agricultural Research | Grandjean F.,University of Poitiers | Le Gentil J.,French National Institute for Agricultural Research | Cherbonnel C.,Genindexe | Evanno G.,French National Institute for Agricultural Research
Conservation Genetics Resources | Year: 2011

Atlantic salmon and brown trout frequently co-occur in the same habitats and juveniles of both species are difficult to discriminate. Hybridization between the two taxa has also been widely documented especially in endangered populations hence the need for species-specific molecular markers. Here we show that the microsatellite marker SsAD486 has two species-specific alleles allowing the identification of Atlantic salmon, brown trout, and their hybrids throughout the European range of these species. Since this marker is polymorphic in Atlantic salmon populations from Western Atlantic, it could also help discriminating between North American and European salmon. © 2010 Springer Science+Business Media B.V.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: ENV.2007. | Award Amount: 5.62M | Year: 2008

Over the past two decades, an increasing proportion of North Atlantic salmon are dying at sea during their oceanic feeding migration. The specific reasons for the decline in this important species are as yet unknown, however, climate change is likely to be an important factor. In some rivers in the southern part of the salmons range, wild salmon now face extinction. This is in spite of unprecedented management measures to halt this decline. Arguably the greatest challenge in salmon conservation is to gain insight into the spatial and ecological use of the marine environment by different regional and river stocks, which are known to show variation in marine growth, condition, and survival. Salmon populations may migrate to different marine zones, whose environmental conditions may vary. To date it has been impossible to sample and identify the origin of sufficient numbers of wild salmon at sea to enable this vital question to be addressed. SALSEA-Merge will provide the basis for advancing our understanding of oceanic-scale, ecological and ecosystem processes. Such knowledge is fundamental to the future sustainable management of this key marine species. Through a partnership of 9 European nations the programme will deliver innovation in the areas of: genetic stock identification techniques, new genetic marker development, fine scale estimates of growth on a weekly and monthly basis, the use of novel high seas pelagic trawling technology and individual stock linked estimates of food and feeding patterns. In addition, the use of the three-dimensional Regional Ocean Modelling System, merging hydrography, oceanographic, genetic and ecological data, will deliver novel stock specific migration and distribution models. This widely supported project, provides the basis for a comprehensive investigation into the problems facing salmon at sea. It will also act as an important model for understanding the factors affecting survival of many other important marine species.

Valette V.,Genindexe | Filipova L.,University of Poitiers | Vuillaume B.,French Natural History Museum | Cherbonnel C.,Genindexe | And 4 more authors.
Conservation Genetics Resources | Year: 2013

A (GA)n and (GT)n microsatellite-enriched library was constructed and 25 nuclear simple sequence repeat (SSR) loci were characterized in the Lesser Antillean Iguana (Iguana delicatissima). All SSR loci were found to be polymorphic after screening for diversity in different cultivars, and a cross-taxa amplification tests showed the potential transferability of most SSR markers in Iguana iguana. First to be published for I. delicatissima, this new SSR resource will be a powerful tool for intraspecific genetic studies and for investigation of hybridization events with Iguana iguana. © 2012 Springer Science+Business Media B.V.

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