Biography:

Hai-Ying Mary Cheng obtained her Ph.D. in Neuroscience from the University of Toronto in 2003 in the laboratory of Dr. Josef Penninger. In 2004, she joined the laboratory of Dr. Karl Obrietan at the Ohio State University, where she investigated the roles of MAPK signaling and microRNAs in the regulation of circadian rhythms in mice. Mary’s research combines mouse genetics, behaviour, neuropharmacology, cellular and molecular approaches, and confocal imaging to provide a functional and mechanistic link between a discrete gene and the behaviour that it modulates. Her work has been published in such journals as Cell, Neuron, Nature, Nature Cell Biology and Proceedings of the National Academy of Sciences. In January 2008, she joined the Ottawa Institute of Systems Biology at the University of Ottawa as Assistant Professor.

Short summary of research interests:

All organisms have biological clocks, which drive and coordinate circadian rhythms in behaviour and physiology in accordance with the demands of our 24-hour world. In mammals, the master biological clock resides in the suprachiasmatic nuclei (SCN) of the hypothalamus. The SCN has endogenous pacemaker activity that runs at near-24-hour cycles and is regulated by the environmental light cycle, thereby allowing the organism to synchronize its internal clock timing mechanism with daily and seasonal variations in the day/night cycle. Many of us are familiar with the adverse effects of a disrupted biological clock—as a result of environmental conditions (eg., jet lag, night-shift work), or , for the more unfortunate, genetic inheritance (eg., familial advanced sleep phase disorder) and disease (eg., cancer, bipolar disorder). While genetic studies have established that the circadian clock is comprised of a set of 'core' clock proteins that interact in interlocking transcription/translation feedback loops to drive rhythms in their own gene expression, our knowledge of the regulatory processes that feed into this molecular clock remains nebulous. Which cascades of cellular events are needed to couple environmental light to the molecular clock? How do individual clock cells synchronize with each other to produce an ensemble rhythm in a tissue? How does aberrant regulation of the circadian clock impact on other biological clocks such as the one controlling cell division? The overall objective of our laboratory is to elucidate the cellular mechanisms that regulate biological timing in mammals, and, in turn, to understand how these cellular mechanisms manifest themselves at the "organism" scale such as animal behaviour, and play a role in diseases arising from their abnormal functioning.