Projects / Programmes
Rehabilitation plan for the Adriatic Grayling (Thymallus aeliani) in Slovenia using novel genetic markers
| Code |
Science |
Field |
Subfield |
| 4.02.01 |
Biotechnical sciences |
Animal production |
Genetics and selection |
| Code |
Science |
Field |
| B402 |
Biomedical sciences |
Aquaculture, pisciculture |
| Code |
Science |
Field |
| 4.02 |
Agricultural and Veterinary Sciences |
Animal and Dairy science |
grayling, Thaymallus aeliani, Adriatic basin, conservation, molecular markers, NGS, genetics, RAD, genomics, commercial breeding
Researchers (4)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
37309 |
PhD Jernej Bravničar |
Animal production |
Technical associate |
2016 - 2019 |
36 |
| 2. |
35373 |
PhD Ida Djurdjevič |
Animal production |
Researcher |
2016 - 2019 |
35 |
| 3. |
11906 |
PhD Aleš Snoj |
Animal production |
Head |
2016 - 2019 |
219 |
| 4. |
15658 |
PhD Simona Sušnik Bajec |
Biochemistry and molecular biology |
Researcher |
2016 - 2019 |
194 |
Organisations (1)
Abstract
European rivers are inhabited with widely distributed Thymallus thymallus, occurring in several evolutionary lineages linked to specific geographical areas. Among them are Sava and Adriatic lineage (Adriatic g.), which are geographically close, but genetically quite distant. Species range of Adriatic g. is confined to rivers of the Adriatic basin in northern Italy (Po and Adige basin) and western Slovenia (upper Soča basin). Although Adriatic g. is mostly regarded as T. thymallus, it was first scientifically described in 1848 based on specimens from Lake Maggiore, Italy as T. aeliani. The uniqueness of Adriatic g. was later also confirmed by genetic analyses. Adriatic g. in Slovenia has been threatened for several decades, mainly due to stocking with Sava grayling. The result of stocking is a hybrid population in the Soča basin. A native population with as high proportion of native genes as possible should be established for restoration. This can be achieved by genetic testing and selection of the most appropriate specimens for further rearing and stocking. The extant genotyping test, which has been carried out annually during spawning, is based on insufficient number of microsatellite loci, which do not give reliable information on the level of introgression. In addition, a major problem represents the fact that pure native populations do not exist in Slovenia anymore. The Natural History Museum in Vienna holds a collection of museum specimens of grayling, originating from the 19th century. This collection will serve as a reference material of genetically pure Adriatic g., but due to high degradation of DNA in these samples efficiency of current diagnostic tests is low. Recently, Adriatic g. population with more than 90% of indigenous genetic pool has been discovered in the upper Adige River in Italy representing a valuable material that might potentially be included in repopulation program of Adriatic g. in Soča River. However, it is imperative to carry out tests of phylogenetic and adaptive compatibility between Soča and Adige population in the first place. Due to described drawbacks, there is a need of a new genotyping test, which would base on single nucleotide polymorphisms (SNPs) in nuclear DNA and would in addition to higher ability for populations discerning, determine evolutionary relationship and degree of introgression. SNPs will be identified using Next Generation Sequencing (NGS) by performing RAD genotyping, which will allow identification of a mass of neutral markers and possibly some adaptive SNP markers. This approach will also enable genotyping of museum specimens and thus to obtain insight into the genetic structure of Adriatic g. as it was 100 to 200 years ago. Identified SNPs will also be used for preliminary genome-wide association study; we tend to evaluate functionally important genomic specificities of populations (e.g., hatchery vs. wild populations; Adige vs. Soča…). In the final phase of the project we will prepare the basis for new genotyping test, useful in further steps of Adriatic g. conservation genetics and also in selection of brood stock of Adriatic g. for commercial breeding, and to assess the taxonomic status of Adriatic g., and to prepare recommendations for a new revitalization program. At the same time we will publish a list of obtained SNP markers and make the available to researcher for studying genetics of other grayling lineages and populations.
Significance for science
The presented project matches with a contemporary research trend of conservation biology, i.e. conservation genomics, which is based upon genomic studies with methodological support of next-generation sequencing. According to our knowledge, this project will represent the first comprehensive conservation genomic study in Slovenia and will be a valuable conceptual starting point for similar studies on other threatened species.
New approaches to be introduced to solve the proposed problems on the Adriatic grayling are:
- Development of specific SNP markers using NGS technology
- Development of diagnostic test for routine typing of introgression of the Adriatic grayling with non-native genes.
The results of the project will represent a baseline for taxonomic revision of the Adriatic grayling with the final goal of its formal recognition as a distinct species T. aeliani, which gives the project also relevance in terms of vertebrate taxonomy.
A wider range of identified/obtained SNP markers could be used for population genetic studies of other European grayling populations.
Significance for the country
The Adriatic grayling is extremely attractive to fly-fishing, which has immense impacts on local economy. By the restauration of the Adriatic grayling and its recognition as a distinct species T. aeliani, the value of the fly-fishing in the upper Soča valley will additionally gain by including a special endemic species in its offer. So rehabilitation of the Adriatic grayling is expected to have a major impact on the economic sector of tourism related to fly-fishing, and thus on revitalization of the less developed region of Posočje.
The grayling producers in Slovenia will be able to sell Adriatic grayling to Friuli Venezia Giulia region in Italy for repopulation purposes.
Despite high appreciation of grayling in gastronomy, these fish haven’t been available on fish market in Slovenia yet. Introduction of commercial breeding of grayling will make this possible. Moreover, since a special type of local grayling is concerned, this novelty product will even be more exclusive giving an additional value to the commercial breeding of the Adriatic grayling.
Most important scientific results
Most important socioeconomically and culturally relevant results
Final report
