Biological Physics Seminar:"Highly multiplexed DNA-FISH for characterizing chromatin organization"

Wed, 18/12/2019 - 10:00 to 11:30

Danciger B building, Seminar room
Lecturer: Seon Kinrot, Harvard
Thephysical structure of chromatin plays an important role in many key biologicalprocesses – from cell cycle progression to regulation of gene expression. Inthe past decade, Hi-C has been instrumental in illuminating the organization ofthe genome into multiple structures across different length-scales. Forexample, chromatin has been shown to organize in topologically associateddomains (TADs) – regions on the order of 100s of kilobases in length whichexhibit a tendency to self-interact and are sensitive to acute depletion of theprotein cohesin. However, despite the development of many tools to characterizethese structures, reliably determining chromatin organization in individualcells remains challenging. Recently, we have developed multiplexed DNA-FISHmethods to visualize many chromatin loci in individual cells and tracechromatin regions of interest. Here, we present an application of this methodto trace Megabase-scale chromatin regions at 30 kilobase resolution. Ourapproach showed the existence of single-cell domain-like structures whichappear to give rise to TADs when averaged across the population, and thelocation of their boundaries (but not their existence itself) is sensitive tocohesin depletion. We further present a method to drastically increase themultiplexing capability of our approach, with exciting potential applications.