Carolyn
Jahn, PhD
Assoc Professor
Department of Cell & Molecular Biology
To Contact Dr. Jahn:
phone:312-503-2955
e-mail: c-jahn@northwestern.edu
Dr. Jahn's website
PubMed
Reference Lookup
Research Interests
Mechanisms of Genome
Rearrangement in Ciliated Protozoa
During the sexual phase of their life cycle, ciliated protozoa dramatically
reorganize their genome via two processes: a) chromosome fragmentation with
telomere addition and b) precise deletion. In Euplotes crassus, these are
abundant processes that can be readily studied in a synchronized cell population.
Dr. Jahn’s long term interest has been in defining how these processes
are carried out in such a global way and how they are controlled so that they
occur in such a precise manner. She expects that the mechanisms at work will
have broad implications for understanding how genomes evolve and how chromosome
and genome structural integrity is maintained.
Identifying Genetic
Modifiers in the Mouse
Several recent reviews of mouse genetics and the mouse genome project have
noted that one aspect of mouse genetics that will be greatly facilitated by
the completion of the genome sequence and that holds great promise for the
modeling of human inherited disease (or disease susceptibility) is the ability
to identify “modifier genes” (genes that modify the phenotype
of a mutation). In other model organisms, the search for modifier genes is
readily carried out by mutagenesis and screening, but this is impossible in
mammals because of the number of animals that need to be examined. Nevertheless,
modifiers can be identified in the mouse by examining the phenotype of a mutation
on different inbred strain backgrounds. Because inbred strains are homozygous
for a particular assortment of alleles, each strain provides a unique collection
of genes and a unique genetic background. Many inbred strains have been well
characterized and are known for their distinct differences in disease susceptibilities.
The project that Carolyn Jahn has initiated while on sabbatical in Doug Engel’s
lab, involves the search for genetic modifiers of the small maf genes, MafG
and MafK. The Engel lab started this project by breeding the maf knockout
mutations into different inbred strains to generate congenics (essentially
differing from the inbred strain at only the gene being crossed into the strain).
In the past year, Dr. Jahn has characterized the phenotypes of the mafG and
mafK mutations in various combinations in two of these strains and have carried
out a regimen of breeding to determine what sorts of modifiers we could potentially
identify. She is currently carrying out whole genome scans to identify the
chromosomal locations of potential modifiers.