Kathleen Hill, Western University
Associate Professor
Department of Biology
London, Ontario
khill22@uwo.ca
Office:
(519) 661-2111 ext. 81337
Expert In
Bio/Research
My research interests encompass Genomics, Mutagenesis, Aging, Cancer and Neurodegeneration. Current projects include bioinformatics, study of genomic sequence organization, and "mutation showers", as well as collaborations in the Experimental Eye Research Facility.
Research Interests:
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Research Interests:
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Bio/Research
My research interests encompass Genomics, Mutagenesis, Aging, Cancer and Neurodegeneration. Current projects include bioinformatics, study of genomic sequence organization, and "mutation showers", as well as collaborations in the Experimental Eye Research Facility.
Research Interests:
Mutation Scene Investigation
Tracking down mutagens and mutational mechanisms
Research in my laboratory is focused on tracking down the mutagens and mutational mechanisms responsible for the spontaneous mutations observed in all tissues over a lifespan. Spontaneous mutations are implicated in aging and aging-associated diseases such as cancer and neurodegeneration but the mutagens and mechanisms for these mutations are frequently unknown. Understanding the origins of spontaneous mutations is predicted to greatly assist in the design of effective strategies for antimutagenesis and ultimately disease prevention.
I focused my research efforts over the last 12 years on the use of a transgenic mouse mutation detection system to study spontaneous mutations in the soma and germline over the lifespan of the mouse. The work began as my postdoctoral training in the laboratory of Dr. Steve Sommer at the Mayo Clinic and City of Hope and more recently (2003) with the establishment of my research program back home in Canada at The University of Western Ontario.
Transgenic mice permit measurement of the frequency and types of mutations in individual tissues in vivo. Transgenic rodents containing a bacterial gene as a retrievable mutational target are useful in assessing the DNA landscape in the aftermath of exposures to endogenous and exogenous mutagens. These transgenic rodent systems permit quantitative measurements regarding mutation frequency and qualitative analysis regarding the types of mutation. It is possible to characterize the predominant types of endogenous mutations and distinguish novel mutagen signatures. A well-validated system is the Big Blue® transgenic mouse mutation detection assay (Stratagene). The E. coli lacI gene within the lambda phage genome was integrated in the Big Blue mouse genome as a multicopy concatemer on chromosome 4. The lacI sequences can be retrieved from high molecular weight DNA, packaged into virulent phage and used individually to infect E. coli. Those lambda phage genomes containing a wild type lacI sequence produce a clear plaque in the bacterial lawn and those lambda phage genomes harbouring a mutation in the lacI sequence due to a mutational event in the mouse produce a blue plaque in the E. coli lawn. In this genetic screening assay, the blue “mutant” plaque phenotype is the result of the dysfunctional lacI repressor protein that fails to repress the expression of lacZ leading to production of B-galactosidase and cleavage of the chromogenic substrate X-gal in the growth media. Mutations that occur in the mouse are harvested as blue mutant plaques and their frequency compared to the total number of viral genomes harvested is the measure of mutant frequency. The individual mutations are identified following DNA sequencing of the lacI gene and the frequency of individual mutational events is estimated. Transgenic mouse mutation detection systems are currently a national and international standard assay for assessment of in vivo mutation frequency and pattern in individual tissues. A recent review by a team of Canadian researchers is an excellent source of information regarding transgenic rodent mutation detection systems 1
The Big Blue system contributes novel observations that contradict conventional thought on spontaneous mutagenesis. We collaborate with Steve Sommer’s group at The City of Hope and analyze a large database of somatic and germline spontaneous mutations collec ted using the Big Blue® mutation detection assay. We have the ability to compare these mouse mutations with a database of germline mutations in human factor VIII and IX genes.
Click to Shrink <<
Research Interests:
Mutation Scene Investigation
Tracking down mutagens and mutational mechanisms
Research in my laboratory is focused on tracking down the mutagens and mutational mechanisms responsible for the spontaneous mutations observed in all tissues over a lifespan. Spontaneous mutations are implicated in aging and aging-associated diseases such as cancer and neurodegeneration but the mutagens and mechanisms for these mutations are frequently unknown. Understanding the origins of spontaneous mutations is predicted to greatly assist in the design of effective strategies for antimutagenesis and ultimately disease prevention.
I focused my research efforts over the last 12 years on the use of a transgenic mouse mutation detection system to study spontaneous mutations in the soma and germline over the lifespan of the mouse. The work began as my postdoctoral training in the laboratory of Dr. Steve Sommer at the Mayo Clinic and City of Hope and more recently (2003) with the establishment of my research program back home in Canada at The University of Western Ontario.
Transgenic mice permit measurement of the frequency and types of mutations in individual tissues in vivo. Transgenic rodents containing a bacterial gene as a retrievable mutational target are useful in assessing the DNA landscape in the aftermath of exposures to endogenous and exogenous mutagens. These transgenic rodent systems permit quantitative measurements regarding mutation frequency and qualitative analysis regarding the types of mutation. It is possible to characterize the predominant types of endogenous mutations and distinguish novel mutagen signatures. A well-validated system is the Big Blue® transgenic mouse mutation detection assay (Stratagene). The E. coli lacI gene within the lambda phage genome was integrated in the Big Blue mouse genome as a multicopy concatemer on chromosome 4. The lacI sequences can be retrieved from high molecular weight DNA, packaged into virulent phage and used individually to infect E. coli. Those lambda phage genomes containing a wild type lacI sequence produce a clear plaque in the bacterial lawn and those lambda phage genomes harbouring a mutation in the lacI sequence due to a mutational event in the mouse produce a blue plaque in the E. coli lawn. In this genetic screening assay, the blue “mutant” plaque phenotype is the result of the dysfunctional lacI repressor protein that fails to repress the expression of lacZ leading to production of B-galactosidase and cleavage of the chromogenic substrate X-gal in the growth media. Mutations that occur in the mouse are harvested as blue mutant plaques and their frequency compared to the total number of viral genomes harvested is the measure of mutant frequency. The individual mutations are identified following DNA sequencing of the lacI gene and the frequency of individual mutational events is estimated. Transgenic mouse mutation detection systems are currently a national and international standard assay for assessment of in vivo mutation frequency and pattern in individual tissues. A recent review by a team of Canadian researchers is an excellent source of information regarding transgenic rodent mutation detection systems 1
The Big Blue system contributes novel observations that contradict conventional thought on spontaneous mutagenesis. We collaborate with Steve Sommer’s group at The City of Hope and analyze a large database of somatic and germline spontaneous mutations collec ted using the Big Blue® mutation detection assay. We have the ability to compare these mouse mutations with a database of germline mutations in human factor VIII and IX genes.
Click to Shrink <<