Domestication of the horse and its genetic diversity
Hans Ellegren (project leader)
Summary of results with list of publications from Uppsala University.
Email: Hans.Ellegren@ebc.uu.se
The horse in the service of humans
The domesticated horse carries a large number of developmental lineages, the explanation for which may be that it was domesticated in many places on earth when the reputation of its usefulness became widespread. Most genetic studies of domesticated animals have analysed mitochondrial DNA. Since this molecule is inherited through the mother, it does not reflect the paternal contribution to development. In order to study this, it is necessary to analyse the Y chromosome, something that was not possible before owing to lack of knowledge of its genetic composition.
In this project, genetic markers were developed from the equine Y chromosome which were analysed in a large number of stallions from different breeds in Europe and Asia. The study showed that all carried the same single chromosome haplotype, in sharp contrast to the large genetic diversity that was previously seen in the equine mitochondrial DNA. One possible cause may be that humans have, right from the beginning, exercised a strong sex bias with their stallions, and that in time one single equine lineage became dominant.
Functional genomics of domestic animals
Leif Andersson (project leader)
Summary of results with list of publications from Uppsala University.
Email: leif.andersson@ibim.uu.se
The objective was to study gene function and the way genes influence various biological processes. The phenotype of the individual comprises the characteristics we can observe and record, and is determined by both inheritance and the environment, and therefore changes during life. Knowledge of the genome of higher organisms has dramatically increased over the past 20 years. On the other hand, we know little of the genetic background to more subtle phenotypical differences between individuals.
Brown fat has an important role in the thermoregulation of mammals. Strangely enough, brown fat has never been documented in domestic pig – a function that was perhaps lost during domestication. It has now been found that this must have happened much earlier, since the gene that is of essential importance for brown fat tissue had been inactivated in a forefather of wild boar and other pigs.
The wild boar is the only ungulate that builds a nest in which the piglets keep warm by snuggling up close together to retain their body temperature. In modern pigsties, thermoregulation of the piglets is assisted by heat lamps. The probable explanation for the need for heat lamps is loss of UCP1 and the ability to produce brown fat.
Quality assessment of bovine embryos
Ylva Brandt (project leader)
Summary of results with list of publications from Scottish Agricultural College.
Email: ylvacbbrandt@hotmail.com
Today it is possible to produce early embryos in a laboratory environment, but we still do not know a lot of the needs and metabolism of the egg cell and the early embryo. Embryo quality is today mainly based on visual inspection and assessment under the microscope. Since this is largely a subjective judgment by the assessor, we should also have access to objective assessment methods. Embryos wholly or partially produced in a laboratory environment can be used in spreading genetic material to those in need all over the world without having to carry live animals over long distances. The embryos can be frozen for long term storage, to be thawed out and implanted in a recipient animal.
The methods used in culturing embryos in the laboratory must be biologically safe. One common additive to the culture media for embryos is serum albumin. Since all products that originate from animals may be the carriers of contagion, other substances are used as a substitute. By avoiding relatively poorly defined serum albumins, a better idea can be obtained of all the constituents in the culture medium and knowledge of the need and metabolism of the early embryo can be enhanced.
Responsible for this page: Kerstin Franklin