8月17日: Computational Study of Genomics and Epigenomics: from statistical analysis to biology
(Associated Professor of Physics, The George Washington University)
Eukaryotic genomes are organized into chromatin, with nucleosome as the fundamental unit. As the substrate for all transactions involving DNA, chromatin plays a critical role in gene regulation and development. Chromatin structure and function are modulated by a myriad of post-translational modifications on the histone tails of nucleosomes. As a major component of the epigenome, these chemical modifications are able to encode a huge amount of information and serve as the carrier of dynamical cellular memory. Nature has developed intricate systems to read and write this information. Thanks to recent advances in the next generation sequencing technology, the genomic landscapes of modified histones in higher eukaryotes have become available using chormatin immunoprecipitation followed with high-throughput sequencing (ChIP-Seq). These landscapes, however, turn out to be rather noisy and diffuse. I will discuss methods we developed for sensitive and efficient identification of signals and domain structures in the epigenomic landscape. In addition, I will present examples of important and unique information about gene regulation provided by these high-throughput functional genomic and epigenomic data. In particular, I will discuss a novel regulatory mechanism in T cell activation that we uncovered by integration of RNA-Seq and ChIP-Seq.