Figure 4.

Use of Human Artificial Chromosomes to Study Centromeric Chromatin

A synthetic α-satellite DNA construct was used to generate human artificial chromosomes (HACs) in HT1080 fibrosarcoma cells. An example of the HAC (white arrow) stained for kinetochore protein CENP-C (red) and DNA (blue) is shown. The presence of tetracycline operator sequences in the synthetic array allows targeting of chimeric proteins containing a range of chromatin modification activities into the HAC centromere. These studies reveal that centromere activity requires finely balanced transcription in a repressive environment. Micrograph by Jan Bergmann.