Extended Data Figure 4. Individual inactivation of Hoxa13 or Hoxd13 is not sufficient to fully abrogate antisense transcription in distal limbs.

a, b, Whole-mount in situ hybridization, using probe A (see Fig. 1) to detect all antisense transcripts, on Hoxd13^−/− (a) and Hoxa13^−/− (b) mouse limb buds at E11.5. Antisense transcription in distal limbs remains robust in both mutants but a clear reduction is seen in the distal Hoxa13^−/− limbs. Original magnification, ×31.5.