Figure 3

Expression of MaLab, MaPb, and MaHox3 in M. alaskensis larval development. All images and diagrams show lateral views with larval anterior up and future juvenile anterior to the left. Asterisk marks apical organ. (A) MaLab is expressed in the trunk discs (td) at trunk-discs stage. The cephalic disc (cd) and stomach (st) are marked for reference. (B) In head-and-trunk-stage larvae, MaLab is expressed in portion of the trunk rudiment (tr) and dorsal disc (dd). The head rudiment (hr) is marked for reference. (C) In complete-proboscis-stage larvae MaLab is expressed in a large portion of the juvenile posterior, from just up against the cerebral organ (co). (D) MaPb is expressed initially in trunk discs (td) at trunk-discs stage. (E) In head-and-trunk-stage larvae, MaPb is expressed in a central domain of the trunk rudiment (tr). (F) In torus-stage larvae, MaPb is expressed in a small central domain of the juvenile posterior. (G) The onset of MaHox3 expression occurs at the trunk-discs stage in the trunk discs (td). (H) In head-and-trunk-stage larvae, MaHox3 is expressed in a central domain of the trunk rudiment (tr) and in a portion of the dorsal disc (dd). MaHox3 is not expressed in the larval body or head rudiment (hr). (I) In extended-proboscis-stage larvae, MaHox3 is expressed in a narrow stripe of the juvenile posterior. Proboscis rudiment (pb) marked in image. Anterior spots are amniotic pigment spots (see Figure 2) that happen to be in focus in this image. (A’-I’) diagrammatically illustrate expression patterns in the three respective developmental stages.