Zoe Lohn
Thursday, July 22nd, 2010, 9:00am. Rm. 226 Michael Smith
Laboratories
“A New
Role for the Tumour Suppressor, lin-35,
During Meiotic Recombination in Caenorhabditis
elegans”
EXAMINING
COMMITTEE
Chair: Dr. Rob
Kay (Medical Genetics)
Supervisory
Committee: Dr. Ann Rose, Research Supervisor (Medical Genetics), Dr.
Hugh Brock (Genetics)
University
Examiner: Dr. Stefan Taubert (Medical Genetics)
SUPERVISORY
COMMITTEE
Dr. Ann Rose, Dr. Don Riddle & Dr. Hugh Brock
ABSTRACT
Meiosis
is a fundamental biological process used by sexually reproducing species to
ensure the faithful transmission of genetic material. In humans, failure to recombine properly during meiosis
causes genetic conditions in the human conceptus such as aneuploidy and
spontaneous abortion.
An
excellent model organism for the investigation of meiotic recombination is the
nematode, Caenorhabditis elegans,
which has many conserved meiotic processes. In this thesis, I have investigated
the role of LIN-35 in meiotic crossing over. LIN-35 is the C. elegans ortholog of the retinoblastoma protein, well
characterized with respect to its role in gene transcription and cell
proliferation. My results show
that mutation in the lin-35 gene
alters recombination frequency differentially for several regions of the
chromosome, causing increases in recombinationally suppressed regions and
decreases in highly recombinogenic regions. In combination with Rec-1, a mutant known to alter crossover
distribution, crossovers across the length of the entire chromosome, were
decreased. In addition, other
severely detrimental phenotypes were observed. For example, gametic viability was reduced dramatically in
the double mutant, compared to either mutant alone. Thus, Lin-35 and Rec-1 are
synergistic, indicating that they act in different pathways. In summary, Lin-35 function plays a
role in achieving normal levels of meiotic recombination, a role that may be
related to its function in chromatin modification and gene transcription.
BIOGRAPHICAL
NOTES
Born: November
20th 1986, Vancouver, British Columbia
Academic Studies: B.Sc.
Queen’s University, 2008
Current
Position: MSc candidate, University of British Columbia
GRADUATE
STUDIES
Field of
Study: Medical Genetics
Courses:
MEDG 419: Human Cytogenetics, Dr. Carolyn Brown
MEDG 520: Advances in Human Molecular Genetics, Dr. Matthew Lorincz
MEDG 530: Human Genetics, Dr. Jan Friedman
MEDG 535: Genetics and Ethics, Dr. Anita Ho
MEDG 545: Current Topics in Medical Genetics Research, Dr.
Carolyn Brown
MEDG 548: Directed Studies, Dr. Ann Rose
MEDG 549: Thesis Course, Dr. Ann Rose
AWARDS
Entrance Scholarship, Genetic Counselling Program, UBC
(2010)
Dean’s Honours Award, Queen’s University (2008)
PUBLICATIONS
Jones M, Lohn Z
and Rose A. “Specialized Chromosomes” Methods in Cell Biology. (In Press)
PRESENTATIONS
Lohn Z and Rose
A. A new role for the tumour suppressor, lin-35,
in meiotic recombination in C. elegans.
(Poster) UBC Department of Medical Genetics Research Day. November 6th 2009.
Lohn Z and Rose
A. Do chromatin modifiers affect the meiotic pattern in C. elegans? (Poster) Canadian Human Genetics Conference, Harrison
Hot Springs, BC, Canada. May 24th-27th 2009.
Zoe Lohn Defense Programme (pdf)