Stefan Hanslik PhD Student

Institut für Tierzucht und Genetik,
Veterinärmedizinische Universität Wien
Veterinärplatz 1
A-1210 Wien

date of birth: 22/01/72
nationality: Austria
education: 1998 graduation in Zoology and Genetics at the University of Vienna

Detecting selective sweeps in Cattle

During the last decades cattle breeds such as the Holstein Friesian have been strongly selected for milk production. In North American Holstein populations milk production increased within 20 years from 4,5 to 6,8 tons/cow. Thus, Holstein cattle provide a good model to study directional evolution. Directional selection is expected to reduce variability at selected loci and their flanking genomic region. Neutral markers such as microsatellites can be used to screen for patterns of reduced variability, which may be indicative of a selective sweep. Various breeds from Northern America and Europe are surveyed. Research focuses on detecting population-specific reductions of variability at individual loci, as this may indicate a selective sweep.

Furthermore we work on the developement of a new statistical test to distinguish directional selection form reduced effective population size.

Isolation of haplotypes

The second major part of my work is the isolation of bovine haplotypes. Microsatellite loci will be isolated from known chromosomal locations. Together with a set of 12 closely linked microsatellite loci, which are located on the same chromosome, haplotype frequencies will be calculated. They should help to create a network phylogeny of different cattle populations from Europe America India and Africa. With the help of haplotype networks we want to work out detailed information about the developmental histories of particular breeds.

                S.Hanslik, B.Harr, G.Brem & C.Schlötterer  (2000) Microsatellite analysis reveals substantial genetic differentiation     between contemporary New World and Old World Holstein Friesian populations. Animal Genetics, 31, 31-39.
                  S.Hanslik, L.Kruckenhauser (2000) Microsatellite loci for two European Sciurid species (Spermophilus citellus, Marmota marmota). Molecular Ecology , in press

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