Research in my laboratory is centered on the study of cell proliferation and cell transformation. The control of gene expression in quiescent primary chicken embryo fibroblasts (CEF) is the focus of our current research program. In particular, we recently uncovered a novel response to the conditions of limited oxygen concentrations experienced by contact inhibited CEF and showed that this response is critical for the maintenance of lipid/membrane homeostasis and cell survival. Current investigations have for objective to characterize the cellular processes regulated by the lipid/membrane damage response promoting reversible growth arrest and survival of quiescent cells. To do this work we employ basic techniques of cell and molecular biology as well as genomic, proteomic and lipidomic approaches.

Our research in microbiology is focused on the soil bacterium Sinorhizobium meliloti that forms N2-fixing root nodules on leguminous plants. The genome of S. meliloti consists of a typical chromosome (3.6 Mb) and pSymA (1.35 Mb) and pSymB (1.68 Mb) replicons. We study genes and processes involved in the interaction of the bacteria with the plant and more generally process that are important for survival in a soil environment. A major current project is to define and manipulate the minimal genes that are necessary and sufficient for nodule formation and N2-fixation. In a key step to achieving a minimal symbiotic genome, we constructed a S. meliloti strain lacking 45% of its genome. In other work, we are studying genes and uptake systems that are regulated in response to phosphate limitation, and in a separate project a locus that confers resistance to bacterial viruses.

Dr. Carmel Mothersill is a radiobiologist and Canada Research Chair in Environmental Radiobiology. Her interests are in the impacts of low dose and chronic radiation exposures on non-human species and on ecosystems. She is developing biomarkers which can indicate effect (harmful or beneficial) at the level of the population, community or ecosystem. Such biomarkers will hopefully be used to aid decision making about the risks of radioactive releases in environmentally sensitive areas. Many of the system level markers identified so far relate to stress responses and immune responses which can be compromised by low level radiation exposures.

Genetic relatedness, parentage and behavioural ecology of colonial and cooperative-breeding birds. My research combines the study of animal behaviour and population biology with the examination of molecular genetic markers. The main areas of research are: the evolution of complex social systems in birds; parental care patterns and mate choice; and genetic effects of environmental mutagen loads as estimated by DNA fingerprint mutation rates. To understand the evolution of communal social system we focus on two communal bird species. In Pukeko, a gallinaceous bird inhabiting New Zealand, groups of one to three males and similar numbers of females raise young at a single nest. Sexual access to laying females is shared among sexually mature males. In contrast, smooth-billed anis, a crotophagid bird of Central and South America, engage in a system of social pairs sharing a single nest and competing for access to the incubated clutch of eggs. Females bury each other’s eggs in the structure of the nest. We have detected mutant fragments of DNA in multi-locus mini-satellite profiles of herring gull families. High levels of polycyclic aromatic compounds (PAC) are associated with steel production facilities and automobile emissions. Rates of genetic mutations are being determined for gull colonies with varying levels of PACs.