UNDERSTANDING THE FUNCTION OF DIFFERENT 3-DIMENSIONAL GENOME ORGANIZATIONS

Abstract

Recent studies identified the condensin II subunit Chromosome-associated Protein H2 (CapH2) as a master-regulator of chromosome territory (CT) formation in Drosophila melanogaster. Specifically, Cap-H2 overexpression in interphase cells disrupts homologous chromosome pairing, inducing chromosome individualization and the formation of distinct CTs. By manipulating this new regulatory pathway, it is now possible to investigate the function of different 3-dimensional chromosome organizations in cells by comparing the expression patterns of cells containing paired chromosomes to those with CTs. To obtain cells containing CTs we generated stable, inducible Schneider 2 (S2) cell lines that express wild-type (WT) Cap-H2. Cells were scored for the formation of normal, weak, and strong CTs over a six day time course. We also conducted cell viability counts on CapH2-expressing cells to determine the effect of CTs on cell health. We found that strong CT formation was most prevalent after six days of Cap-H2 expression. However, cell cultures expressing WT Cap-H2 displayed a reduced number of viable cells over the six day time course. Taken together, we conclude that it requires almost a week of WT Cap-H2 induction for most stable cells to form CTs and CTs cause reduced cell health.