Figure 3.

Xist is expressed in class I somatic cells, and the RNA coats the autosome. (A) RNA/DNA FISH of normal female and Tg fibroblasts. Xist RNA is shown in red; Zfx genomic DNA is shown in green. (B) πJL1.4.1 chromosomes were hybridized to Xist probes (red) without chromosome denaturation, then stripped, denatured, and hybridized to chromosome 3 (Ch3)-specific paints (Ch.paint; red) and Tg probes (green). Arrows indicate normal homologues of Ch3. (C) Xist RNA skips the Xic Tg as indicated by the arrows. This experiment was performed as described for B.