Figures & data
Figure 1.Airn can silence Igf2r at any time by transcriptional overlap. Left: early embryonic stem cell (ESC) differentiation. Airn silences Igf2r on the paternal allele and the Igf2r promoter is in an open chromatin conformation (top). Truncation of Airn from the 3′ end (3′ trunc) after but not before the Igf2r promoter maintains Airn-mediated silencing (middle). To truncate Airn from the 5′ end (5′trunc), the Airn promoter was moved close to the Igf2r promoter: Igf2r was silenced in this case too (bottom). Together, these truncations show that Airn only needs to overlap the Igf2r promoter to silence it and that all 3′ and 5′ sequences are not necessary.Right: late ESC differentiation. Airn-mediated silencing causes the late acquisition of closed chromatin and DNA methylation on the Igf2r promoter, which maintains the silent state when Airn is turned off (left). In the absence of Airn, Igf2r is expressed at high levels and can only be partially silenced by turning Airn on at this developmental time point (right). Note that only the paternal allele is shown.
