In his thesis from the field of population genetics Miika Tapio used molecular markers to study the gene pools of sheep in the Nordic countries, Russia and the Baltics, and studied the variation of mitochondrial DNA in Eurasian sheep.
He analysed 37 northern European sheep breeds by using gene markers inherited from both parents (microsatellites, blood proteins). Tapio examined mitochondrial DNA inherited from only the dam in 76 breeds in an area spanning from northern Europe to the Balkans, the Caucasus and Central Asia. Among other things, the thesis presents a previously undiscovered fourth line of domestic sheep dams that was found in the Caucasus.
The study showed that variation between breeds was clearly greater than typically found in European sheep.
- For example, Finnsheep and Romanov sheep are very different from each other although they are thought to be related, Tapio explains.
Variation between long- and short-tailed sheep was also discovered on the basis of gene markers, but the classification into breed groups only explains a small share of the differences between breeds, as the differences are significant even within breed groups. Gene markers inherited from both parents linked together the breeds that are from adjacent areas.
Diversification of landraces speaks in favour of protection
Northern European native breeds differ from multinational sheep breeds in many ways, forming an important gene pool. So far many native breeds are also less inbred.
- Diversification speaks in favour of keeping the breeds separated in the future as well, Tapio points out.
Northern European landraces are becoming increasingly rare as agricultural production mainly utilises completely different species or multinational sheep breeds.
- Many landraces, such as Finnish Grey landrace, have recently witnessed a significant population decline. The first measures in maintaining sheep gene pools are monitoring the number of animals and avoiding inbreeding with the help of extensive animal registers, Tapio says.
The study determined the protection values of breeds by simultaneously using both within-breed and inter-breed diversity. 19 breeds were assessed to be above others in importance, seven of which are endangered native breeds: Estonian Ruhnu sheep, Finnish Grey landrace, Norwegian Old Spael sheep, Norwegian Grey Troender sheep, Russian Viena sheep, Swedish Dala fur sheep and Swedish Roslag sheep.
Miika Tapio's Doctoral Dissertation "Origin and maintenance of genetic diversity in northern European sheep" shall be examined at the Faculty of Science of the University of Oulu at 12 o'clock on 10.11.2006. The opponent is Dr Michael W. Bruford from the Cardiff School of Biosciences and the custodian is Professor Outi Savolainen from the University of Oulu.
Faba fix for corn's nitrogen need
11.04.2018 | American Society of Agronomy
Wheat research discovery yields genetic secrets that could shape future crops
09.04.2018 | John Innes Centre
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy