Research Activities                              Go Back!

Laboratory:
Department of Fish Farming, Institute of Animal Husbandry, Estonian Agricultural University.
Contact person (name and e-mail):
Tiit Paaver, tpaaver@ph.eau.ee
Persons working on brown trout population genetics:
Riho Gross, Tiit Paaver, Anti Vasemägi
General research topics of the laboratory:
Population structure, Conservation and Management.
General description of research on brown trout population genetics:
Genetics of brown trout (mainly anadromous) is studied besides Atlantic salmon, as the sea trout spawns in Estonia in the same rivers as salmon or is reproduced for stocking simultaneously with salmon. The main goal is to reveal genetic structure and level of differentiation of natural and hatchery populations. This information is used to establish conservation and management strategies for both salmonid species. Whereas the studies were initiated using allozymes, the genetic research is now carried out basically on the DNA level (single copy nDNA genes, microsatellites). Trout studies are on the stage of testing the methods and revealing suitable markers.

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List of projects (brown trout) for the past 3 years:

 

Study #1
Researcher: Riho Gross
Collaborators: Anti Vasemägi, Tiit Paaver, Marje Aid
Source of project funding: Estonian Science Foundation, Estonian Fisheries Foundation.
Topic: Gene diversity, gene flow, genetic monitoring, breeding programs.
Objective: To find new polymorphic DNA markers and use them to estimate the genetic differentiation of native and hatchery populations of trout together with possible effects of stocking of hatchery reared fish on the natural gene pools. To estimate the frequency of Atlantic salmon× brown trout hybrids in Estonian rivers and identify the maternal species.
Design: Samples are taken from the parr caught by electrofishing in Estonian sea trout rivers or collected from hatcheries and analysed by means of electrophoretic analysis of allozymes and PCR amplified mtDNA and nDNA genes.
Methodology: Protein electrophoresis, mtDNA-RFLP, scnDNA-RFLP, single locus microsatellite DNA, heteroduplex analysis of single copy nDNA genes.
Trout population: Anadroumous population.
Origin of samples: Baltic Sea Basin (Atlantic Basin), Estonia (Gulf of Finland, Gulf of Riga).
Status: Started 1997, going to be finished 1999.

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Study #2
Researcher: Riho Gross
Collaborators: Jan Nilsson (Dept. Aquaculture, Swedish Univ. Agricult. Sciences), Tiit Paaver
Source of project funding: Estonian Science Foundation.
Topic: Gene diversity.
Objective: To investigate genetic polymorphism of sea trout growth hormone genes with the aim of finding new genetic markers for population differentiation studies.
Design: Polymorphism of PCR amplified GH1 and GH2 genes was revealed by means of heteroduplex analysis (Gross, Nilsson, 1995) in samples of sea trout parr from three rivers of Gulf of Finland basin.
Methodology: Heteroduplex analysis of scnDNA.
Trout population: Anadroumous population.
Origin of samples: Baltic Sea Basin (Atlantic Basin), Estonia (Gulf of Finland, Gulf of Riga).
Status: Finished in 1995.

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Study #3
Researcher: Riho Gross
Collaborators: Nilsson, J.; Schmitz M. (Dept. of Aquaculture, Swedish University of Agricultural Sciences)
Source of project funding: Nordic Council of Ministers (for R.Gross).
Topic: Natural hybridisation.
Objective: To find new genetic markers for identification of salmon vs. sea trout hybrids.
Design: Species specific AluI digested prepro-gonadotropin releasing hormone gene banding pattern is revealed, which can be applied for identification of hybrid.
Methodology: scnDNA.
Trout population: Anadroumous population.
Origin of samples: Baltic Sea Basin (Atlantic Basin), Estonia (Gulf of Finland, Gulf of Riga), Sweden (Gulf of Bothnia), Mediterranean Sea Basin.
Status: Carried out in 1995.

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Publications (brown trout genetics)

Journal papers:

  • Gross, R. & Nilsson, J. (1995). Application of heteroduplex analysis for detecting variation within the growth hormone 2 gene in Salmo trutta L. (brown trout). Heredity, 74, 286-295.
  • Gross., R., Nilsson, J., Schmitz, M. (1996). A new species-specific nuclear DNA marker for identification of hybrids between Atlantic salmon and brown trout. Journal of Fish Biology, 49, 537-540.

Reports

  • Investigations of genetic structure of salmon and sea trout populations of Estonia. Annual reports of studies financed by Estonian Fisheries Foundation. 1995 (8 pp), 1996 (10 pp), 1997 (15 pp) (in Estonian).
  • Report of study of genetic polymorphism of sea trout growth hormone genes, financed by Estonian Science Foundation grant. 1995. (in Estonian).

 

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