Fig. 3.

The Kcnq1ot1 transcript establishes a lineage-specific nuclear domain. (A) RNA-FISH was performed on E12.5 embryo or placental sections using probes for Kcnq1, Xist and Kcnq1ot1 (green; arrows). Nuclei were counterstained with DAPI (blue) and imaged by confocal microscopy. Images have been processed using Volocity for volume rendering. Scale bars: 10 μm. (B) After RNA-FISH, the volumes of signals for Kcnq1, Kcnq1ot1 and Xist were measured in the placenta, showing significantly different distributions (P<0.0001, χ² test), with the Kcnq1ot1 signal occupying an intermediate volume between Kcnq1 and Xist. (C) Measurements of Kcnq1ot1 signal volumes between the embryo and placenta reveal that the Kcnq1ot1 nuclear domain is larger in the placenta (P<0.0001, χ² test), in line with the larger silencing effect in this tissue.