Title : Spatial movements of chromosomes facilitate their repairs
Speaker : Prof BJ Rao, Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India, 400005,
Date : 17/11/2017, 3:15 PM (Friday), Seminar Hall, First Floor.
Organization is innate to any physical system, more so to a living one. How the details of biological organization sustain, but also gradually evolve is an area of intense research and philosophical debates.
I focus on chromosomal designs in some more details. I demonstrate that DNA polymer sequence (Genetics) is overlaid by additional layers of organization where the sequence is folded and positioned non-randomly in a cellular nucleus (Epigenetics), in tandem with the on-going DNA-repair functions. Chromosomes are non-randomly placed during interphase in mammalian and other higher eukaryotic nuclei in spatial zones referred to as Chromosome Territories (CT). They are dynamically regulated during DNA damage responses (DDR). Nuclear myosin is recruited to the chromatin as a consequence of DDR signaling that lead to the required “powering” of CT relocations. I describe our recent theoretical and experimental approaches that relate these spatial changes to the “transcriptional rewiring” of mammalian nuclei during DDR. I conclude by arguing that a combination of deterministic and stochastic changes in the organization shapes biological and chromosomal functions.