Fig. 4.

Increased dosage of CENP-A causes the CEN domain to expand at endogenous centromeres and on human artificial chromosomes. (A and B) IF-FISH on chromatin fibers using CENP-A antibodies and α-satellite DNA probes spatially defined CEN chromatin domain on DXZ1 α-satellite array at endogenous centromeres and on human artificial chromosomes. (A) CENP-A (red) is present on ≈35% of the human artificial chromosome identified by PAC/α-satellite FISH probe (green). When CENP-A expression is increased (B), CENP-A (red) spreads over ≈80% of the artificial chromosome (green). (Scale bars, 10 μm.) (C) CEN chromatin, defined by CENP-A, also expands at the endogenous X centromere in HT1080 cells.