RNA in situ hybridization of SAD2-clade desaturases in Ophrys flowers.

Additional data for Figure S1: RNA in situ hybridization of SAD2-clade desaturases (SAD1 and SAD2) in Ophrys flowers. (A) Overview illustration showing O. exaltata and O. sphegodes flowers from top and front along with the layout and direction of view of thin sections (starting at the base of the labellum on top toward the apex at the bottom). (B) Two thin sections of O. exaltata labellum, at 3 and 5 mm from the base (top) of the labellum. (C) From top to bottom, O. sphegodes labellum thin sections at 1, 3, 5, 7 and 10 mm from the base (top) of the labellum. The antisense panels show blackish signal in the epidermal layer of O. sphegodes that is clearly stronger than the brownish background signal observed in the sense controls. However, no such difference was observed between sense and antisense signals in O. exaltata epidermis. The difference between O. sphegodes and O. exaltata is consistent with previous gene expression analyses [1, 2] that show SAD2-clade genes to be highly expressed in mature O. sphegodes labellum, whereas expression in O. exaltata labellum was low. The higher level of SAD2 expression as compared to SAD1 expression in O. sphegodes [1, 2] suggests that ISH signal in panel (C) is primarily due to SAD2.
References:
1. Xu et al. (2012). PLoS Genet. 8, e1002889.
2. Schlüter et al. (2011). Proc. Natl. Acad. Sci. USA 108, 5696-5701.