Spatio-temporal Wnt expression during early blostogenetic cycle. Expression patterns of wnt2B (magenta), wnt5A (green), and wnt9A (red) in Botryllus schlosseri buds processed for whole-mount FISH. All images are obtained by an average projection of the confocal z-stack image. The small sketch on the lower left corner of each panels represents the blastogenic stage of the buds shown (blue = secondary bud; light blue = primary bud), and the small arrow indicated their A/P orientation. (A) Confocal image of a primary (B) and secondary (b) buds at stage 9/8/2 showing expression of wnt2B on the emerging budlet (b) early in the blastogenesis. (B)
wnt5A mRNA is expressed in immature germline cells within the gonadal blastema at stage 9/8/2. (C) At the same developmental stages considered, wnt9A is expressed predominantly within the secondary bud (b). Note that the epithelial wall of the vasculature (asterisk) also does express wnt9A.
(D) Sense probe used on untreated buds as negative control for wnt2B. (E) Confocal image of wild type animal stained with a sense probe used as negative control for wnt5A. (F) Enlargement of the secondary bud (b) in panel C showing wnt9A expression. BARS: 200 μm in A, B, C, E. 100 μm in D and F.