Figure 6. Loss of DCC-dependent TADs on X does not disrupt dosage
compensation but does reduce thermotolerance, accelerate aging, and shorten
lifespan. Cartoons of X structure in four genotypes. Red rectangles, rex sites at
DCC-dependent TAD boundary; open rectangles, rex deletions, no TAD boundary. On
8rexΔ X chromosomes, the eight DCC-dependent boundaries found on the wild-type X
are lost, while other DCC-mediated interactions (0.1-1 Mb) and DCC-independent
boundaries remain. In DCC mutants the eight DCC-dependent boundaries are lost as
are the other DCC-mediated interactions. X volume expands in DCC mutant but not
8rex embryos. Inserting a rex site on 8rexΔ chromosomes creates a new boundary.
One rex site is both necessary and sufficient to establish a TAD boundary on X.
