Genetic diversity and differentiation of sea trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>) populations in Lithuanian rivers assessed by microsatellite DNA variation

The genetic diversity and differentiation of sea trout were studied in three river basins in Lithuania: Akmena-Dane, Bartuva, and Nemunas. A total of 282 individuals were genotyped at eight microsatellite loci. A similar level of genetic diversity was found in all of the populations studied: mean allelic richness ranged from 3.64 to 5.03, and average expected heterozygosity ranged from 0.588 to 0.721. Significant genetic divergence was observed among the different river basins as well as between populations within the drainages. All pairwise F _ST values were highly significant, ranging from 0.027 to 0.197. The analysis of molecular variance showed rather weak hierarchical population structuring within the Nemunas basin, which may be explained by extensive gene flow among different river basins or, alternatively, reflect the influence of artificial breeding. Information on genetic diversity and differentiation of the Lithuanian sea trout populations will be useful for future management decisions.     

Novel tools for early detection of a global aquatic invasive,the zebra mussel Dreissena polymorpha

1. This study presents a species‐specific DNA‐based marker for detection of the zebra mussel Dreissena polymorpha, recognized as one of the worst invasive species worldwide.
2. The marker was developed in silico and experimentally tested on environmental samples. Gel and capillary electrophoreses for visualization of the PCR products were compared.
3. Marker specificity and sensitivity were assessed in vitro by cross‐amplifications and serial dilutions, respectively. The method allows detecting at least 0.7 ng of Dreissena DNA per μL and cross‐species amplification was not found in any case.
4. Next‐generation sequencing (NGS) metabarcoding (PCR amplification and massive sequencing of a DNA barcode) was used as an independent method for verifying presence of Dreissena DNA molecules in environmental plankton samples collected from the south‐eastern Baltic Sea.
5. The consistency between NGS results reporting presence of Dreissena and positive PCR amplification of the marker from the plankton samples confirmed the efficacy of this highly reproducible, fast, cheap and technically easy method.

Copyright © 2016 John Wiley & Sons, Ltd.