Research
Activities
| Department of Fish
Farming, Institute of Animal Husbandry, Estonian Agricultural University. |
| Contact person (name and e-mail): |
| 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. |
| 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. |
| 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. |
| 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. |
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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