Albany 2015:Book of Abstracts
June 9-13 2015
©Adenine Press (2012)
Active chromatin regions are sufficient to define borders of topologically associated domains in D. melanogaster interphase chromosomes
In Drosophila, interphase chromosomes are organized in topologically associated domains (TADs) within which chromatin-chromatin interactions are frequent, while interactions across domain borders are rare. TAD positions on chromosomes appear to be conservative between cells of different lineages, and even between animal species. However, molecular mechanisms underlying partitioning of chromosomes in TADs are poorly understood. Insulator elements have been proposed to play a key role in definition of TAD borders but there was no strong experimental evidence to support this hypothesis. Here we used Hi-C method to map TADs in four drosophila cell lines of different origin. The cell lines share up to 80% TAD positions, while cell type specific TAD borders correlate with transcription changes between cell lines. TADs appear to be self-organizing condensed chromatin domains depleted in active chromatin marks. Active chromatin regions that cannot be organized in compact structures separate TADs, being sufficient to establish TAD borders without contribution of insulator proteins, such as Su(Hw) or CTCF.
Ekaterina E. Khrameeva 1
1Skolkovo Institute of Science and Technology