Early embryos have long provided systems for probing the nature of cytoplasm and how it is organized in space and time. The rapid cleavage cycles and precisely defined geometry of embryos exemplify the challenge of understanding how molecular dynamics can collectively generate organization on a scale of tens of minutes and hundreds of microns. In his PhD research, published in 2010, Martin Wühr modernized our view of the microtubule cytoskeleton in early frog and fish embryos and proposed a model for determination of cleavage plane geometry. Wühr’s work left several questions unanswered that our group has been addressing: How do microtubule asters grow to span huge cells, how do they interact to partition the cytoplasm and instruct cleavage furrow location, and most perplexingly, how are they positioned to determine cleavage furrow geometry? Addressing the last question revealed collective movement of all component cytoplasm, including cytosol, and is forcing us to build more realistic models for cytomechanics. 

Biography:

Dr. Mitchison is interested in all aspects relating to microtubules, the cytoskeleton, and cell division. 

Dr. Mitchison received his Ph.D. in Biochemistry and Biophysics from the University of California, San Francisco. During his PhD work at the University of California, San Francisco with Dr. Marc Kirschner, he discovered dynamic Instability of microtubules, a fundamental aspect of cytoskeleton biology and since then has studied the biochemistry, dynamics and spatial organization of microtubules and actin filaments with a focus on cell division mechanisms. Much of his lab's work in this area is based on live fluorescence imaging and has been at the forefront of the application of novel optical methodologies to living cells.

In 1997 he moved to Harvard Medical School to Co-direct the Institute of Chemistry and Cell Biology, a collaboration between chemists and cell biologists, to develop and apply small molecule screening capabilities in academia. As part of this effort, Dr. Mitchison's developed a strong interest in cancer chemotherapy and in more rational approaches to drug development in general. In 2004 he co-founded a new department, Systems Biology, that aims to bring systematic and quantitative methods to bear on problems in basic cell biology and medicine and in 2011 he helped found the Systems Pharmacology initiative at Harvard Medical School, a major interest area within the department, co-Directed by Peter Sorger and himself.

Dr. Mitchison is the Hasib Sabbagh Professor of Systems Biology, and co-Director of the Initiative in Systems Pharmacology at Harvard Medical School.