Institut für Tierzucht und Genetik,
Veterinärmedizinische Universität Wien
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.