Biologisk materiale fra fisk
Forurensing, klimaendringer, overhøsting og menneskelig inngripen er faktorer som påvirker livet både i ferskvann og til havs. Gjennom innsamling av biologisk materiale fra fisk følger NIBIO Svanhovd utviklingen for flere fiskearter i Norge og Europa.
KONTAKTPERSON
Prøvetaking av ørret i Pasvikelva startet i 2015 da stamfisk som brukes i kultiveringen og deres avkom ble kartlagt genetisk, og er et arbeid som fortsatt pågår årlig.
Senere har innsamlingen av prøvemateriale fra fisk i Pasvikvassdraget økt for hvert år og omfatter nå alle arter som finnes i vassdraget.
Øst-Finnmark har i oddetallsår store problemer med invasjon av pukkellaks i deres elver og problemet er økende og sprer seg sørvestover langs kysten av Norge. Som en del av regionen har NIBIO Svanhovd startet med innsamling av pukkellaks fra flere elver i Sør-Varanger kommune til genetiske analyser.
Rognkjeks brukes av oppdrettsnæringen fordi den spiser lakselus. For å kunne finne de beste kandidatene av rognkjeks til avl, kartlegges egenskaper som sykdomsresistens og lusespising genetisk og legger grunnlaget for et bedre avlsprogram.
Publikasjoner
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Forfattere
Simo Maduna Adam Vivian-Smith Ólöf Dóra Bartels Jónsdóttir Albert Imsland Cornelya Klutsch Tommi Nyman Hans Geir Eiken Snorre HagenSammendrag
The lumpfish Cyclopterus lumpus is commercially exploited in numerous areas of its range in the North Atlantic Ocean, and is important in salmonid aquaculture as a biological agent for controlling sea lice. Despite the economic importance, few genetic resources for downstream applications, such as linkage mapping, parentage analysis, marker-assisted selection (MAS), quantitative trait loci (QTL) analysis, and assessing adaptive genetic diversity are currently available for the species. Here, we identify both genome- and transcriptome-derived microsatellites loci from C. lumpus to facilitate such applications. Across 2,346 genomic contigs, we detected a total of 3,067 microsatellite loci, of which 723 were the most suitable ones for primer design. From 116,555 transcriptomic unigenes, we identified a total of 231,556 microsatellite loci, which may indicate a high coverage of the available STRs. Out of these, primer pairs could only be designed for 6,203 loci. Dinucleotide repeats accounted for 89 percent and 52 percent of the genome- and transcriptome-derived microsatellites, respectively. The genetic composition of the dominant repeat motif types showed differences from other investigated fish species. In the genome-derived microsatellites AC/GT (67.8 percent), followed by AG/CT (15.1 percent) and AT/AT (5.6 percent) were the major motifs. Transcriptome-derived microsatellites showed also most dominantly the AC/GT repeat motif (33 percent), followed by A/T (26.6 percent) and AG/CT (11 percent). Functional annotation of microsatellite-containing transcriptomic sequences showed that the majority of the expressed sequence tags encode proteins involved in cellular and metabolic processes, binding activity and catalytic reactions. Importantly, STRs linked to genes involved in immune system process, growth, locomotion and reproduction were discovered in the present study. The extensive genomic marker information reported here will facilitate molecular ecology studies, conservation initiatives and will benefit many aspects of the breeding programmes of C. lumpus.
Til dokument
Forfattere
Cornelya Klutsch Simo Maduna Natalia Polikarpova Kristin Forfang Paul Eric Aspholm Tommi Nyman Hans Geir Eiken Per-Arne Amundsen Snorre HagenSammendrag
Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (Salmo trutta L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations throughout its natural distribution range due to habitat fragmentation, overexploitation, translocations, and stocking. The Pasvik River is a subarctic riverine system shared between Norway, Russia, and Finland, subdivided by seven hydroelectric power dams that destroyed about 70% of natural spawning and nursing areas. Stocking is applied in certain river parts to support the natural brown trout population. Adjacent river segments with different management strategies (stocked vs. not stocked) facilitated the simultaneous assessment of genetic impacts of dams and stocking based on analyses of 16 short tandem repeat loci. Dams were expected to increase genetic differentiation between and reduce genetic diversity within river sections. Contrastingly, stocking was predicted to promote genetic homogenization and diversity, but also potentially lead to loss of private alleles and to genetic erosion. Our results showed comparatively low heterozygosity and clear genetic differentiation between adjacent sections in nonstocked river parts, indicating that dams prevent migration and contribute to genetic isolation and loss of genetic diversity. Furthermore, genetic differentiation was low and heterozygosity relatively high across stocked sections. However, in stocked river sections, we found signatures of recent bottlenecks and reductions in private alleles, indicating that only a subset of individuals contributes to reproduction, potentially leading to divergence away from the natural genetic state. Taken together, these results indicate that stocking counteracts the negative fragmentation effects of dams, but also that stocking practices should be planned carefully in order to ensure long‐term preservation of natural genetic diversity and integrity in brown trout and other species in regulated river systems.
