Fig. 6. Expression patterns of miR166 and REV during embryogenesis. In situ localization of miR166 in wild-type (A-E) and jba-1D/+ (G-L) embryos. (A,G) At the late globular stage, miR166 is expressed in the peripheral region of the hypocotyl and at the tips of the initiating cotyledons (arrows). (B-D,H-J) During the heart and torpedo stages, miR166 expression expands to include the abaxial region and the distal tips of the cotyledons. (E,K) In mature embryos, miR166 expression becomes localized to the SAM, the adaxial region of the cotyledons and the provascular tissues. (F,L) Control hybridization with a miR166 sense probe, at the torpedo stage. (M-Q) REV expression in wild-type embryos. (M) REV is expressed in the central apical region of late globular stage embryos. (N) During the heart stage the REV expression expands to the adaxial region of the cotyledons and the central provascular tissues of the hypocotyl. (O,P) REV expression in early and late torpedo stages is similar to the heart stage. (Q) In mature embryos, REV is localized to the SAM, the adaxial regions of the cotyledons and the central provascular tissues. Scale bars: 500 µm.