Professor Colette L. Picard is bringing her innovative skills in single cell genomics to the Department of Cell & Systems Biology (CSB) as a new professor at University of Toronto. She was drawn to a city packed with life science innovators, and to CSB in particular for our deep expertise in bioinformatics and genomics.
Precision resolution and innovative computational techniques in gene regulation
Picard is a pioneer in single cell analysis of developing tissue. She was one of the first scientists to use new single cell sequencing techniques to probe gene expression in complex tissues in plants, focusing first on the developing seed. This study found that an unusual gene expression pattern called imprinting is elevated in a small region that forms the interface between the seed and the mother plant, highlighting the level of detail that these new single cell sequencing approaches can capture.
Single cell sequencing uses sophisticated high-throughput, low-input techniques to prepare sequencing libraries of thousands of individual nuclei simultaneously. Analyzing these complex datasets poses a number of challenges, and Picard relies on her computational and statistical background to tailor each approach to her biological questions.
Picard is intrigued by how gene expression is regulated, particularly during development. Her studies have converged on epigenetic alterations to DNA, particularly the addition of methyl groups to DNA. Epigenetic modifications alter the expression of the affected regions of DNA. Since all the cells of a developing organism are genetically identical, epigenetic modifications are one way that this single DNA ‘blueprint’ can give rise to a large variety of cell types and behaviors within a tissue or complex organism.
An important model system for the very start of the developing organism
Picard is currently focused on the development of the germline, which in plants occurs when the pollen is formed. Pollen is made of three genetically identical cells, each with distinct behavior and gene expression patterns. Picard is interested in understanding the sequence of epigenetic changes that create the differences between these three cells. In fact, pollen is an excellent model system for developmental biology: it’s simple, abundant, and has only one copy of every gene instead of the normal two.
But it’s not just a great model system; pollen is also important to study. Yields of major crops like corn and wheat depend on pollination. Across the entire lifecycle of the plant, pollen development is particularly sensitive to environmental stress. A heat wave just as pollen grains are forming greatly reduces the formation of viable pollen. Picard will probe the effects of extreme heat on gene expression during pollen development to understand and propose solutions to crop yields reduced by extreme heat.
Growing a lab in Toronto
Professor Picard is currently accepting graduate student applications from those interested in studying gene regulation and epigenetics in germline development. Her lab will consist of both a ‘wet-lab’ equipped to grow plants and run experiments on pollen, as well as a ‘dry-lab’ focusing on the analysis of high-dimensional datasets like single cell sequencing data in a variety of plant and animal systems.
Picard is grateful to her postdoc advisor Steve Jacobsen at UCLA and her PhD advisor Mary Gehring at MIT for their support in her successful application, and looks forward to joining the vibrant scientific community at CSB. She is enjoying getting to know Toronto and reassures us that despite moving here from Los Angeles, she is originally from Michigan and Montréal and is comfortable with the blizzards obscuring our streets.
We are excited to see the discoveries that will come from her research! Welcome, Colette!