Just to the right of the bright white spot, above, a mutant can be seen as a colourless ribbon running from the base of a villus up to the tip in a mouse intestine. The villus below it also has a mutant ribbon and two other mutants are visible.
A mutagen is a substance or agent that causes an increase in the rate of change in genes. These mutations can be passed along as the cell reproduces, sometimes leading to defective cells or cancer. Biological and chemical agents, as well exposure to ultraviolet light or ionizing radiation, are examples of mutagens. Mutagenesis is the formation of mutations.
Affectionately dubbed “Mr. Micronucleus,” biology Professor John A. Heddle (right), Faculty of Pure & Applied Science, was given the Environmental Mutagen Society’s top honour on May 13 – the EMS Award. The award recipient was announced at the society’s 2003 annual meeting in Miami Beach, Florida.
This award is akin to a gold medal and is conferred annually on a scientist, not necessarily a member of the society, in recognition of outstanding research contributions in the area of environmental mutagenesis. Only two Canadians have won this award previously, one of whom was the late Robert Hall Haynes, a York distinguished research professor emeritus of biology. Currently, Heddle is using mutations to study the relationship between diet and cancer, since cancer arises from mutations.
The following information came from Brent Heath, Biology Graduate Program director.
John A. Heddle became known internationally as “Mr. Micronucleus” for having developed the micronucleus assay for chromosomal damage. This test is now a standard international method for detecting such damage and is used to assure the safety of drugs and food additives, as well as many industrial chemicals.
Heddle has done other work with micronuclei, having developed a variation of the method as a research tool. More than 5,000 published papers used his methods or derivatives of them. Interestingly, micronuclei were not referred to in the EMS Award citation. Rather it was his early fundamental research into the mechanisms by which chromosomal aberrations are formed and his most recent work with mutations that were mentioned, together with his ‘strategic thinking’.”
EMS is the primary scientific society fostering research on the basic mechanisms of mutagenesis as well as on the application of this knowledge in the field of genetic toxicology. It was founded in 1969 at Oak Ridge, Tennessee.