Fig. 7: In situ RNA hybridization validates expression of gymnosperm-specific BELL genes in arils, a unique ovule structure in Taxus.
From: Developmentally regulated genes drive phylogenomic splits in ovule evolution
A Representation of Taxus and Cephalotaxus aril morphology relative to other seed plants. B Photographs of aril development in Taxus baccata, the species used to validate the pipeline. C–M In situ hybridization. Imaged sections of Taxus baccata ovules. Purple color indicates the presence of RNA. TbMELBEL1 expression in shoot apical meristem (C), Stage 1 ovule (D), Stage 3 ovule (E), Stage 4 ovule (F), and Stage 5 ovule (G), from six technical replicates. Arrows indicate the megaspore mother cell. TbGBEL2 expression in Stage 1 ovule (H), Stage 3 ovule (I), Stage 4 ovule (J), and Stage 5 ovule (K), from six technical replicates. Expression of control sense probes in young shoot and ovule sections for TbMELBEL1 (L) and TbGBEL2 (M), from three technical replicates. a aril, b bract, i integument, ms megaspore, n nucellus, sam shoot apical meristem. Scale bars (C–M) = 200 µm.
