Fig. 8

Fig. 8 Expressions of Prox1 paralogues and nuclear distribution of β-catenin are right-restricted in the habenulae of the river lamprey.

a,e Confocal images of transverse sections of adult river lamprey habenulae following DAPI staining (blue) and IHC with antibodies directed against acetylated tubulin (green) (a) and β-catenin (red) (e). Higher magnification of the territories boxed in (a2), (e1), (e2) and (e3) are shown in (a2’,a2”), (e1’,e1”), (e2’) and (e3’), respectively. b,c,d Transverse sections of river lamprey habenulae following ISH with probes for LfKctd12l (b), LfProx1la (c) and LfProx1lb (d). Sections in (b,c,d) were obtained from the same specimen. Sections shown in (a1–a3), (b1–b3,) (c1–c3), (d1–d3), and (e1–e3) are anterior to posterior series. White arrrowheads in (a) and black arrowheads in (b,d) point to two territories, which express both LfKctd12l and LfProx1lb in the right habenula: one, delimited by dashed lines in (a2,a3,b2,b3,c2,c3,d2,d3,e3), is located posteriorly and adjacent to the midline, while the other, shown in (a1,b1,d1,e1), is restricted to ventral and anterior levels. Empty arrowheads in (b2,b3,c2,c3) point to discrete posterior LfProx1la territories negative for LfKctd12l. A thin arrow in (a2,b2,c2,d2,e2) points to a right medial territory, delimited by a dotted line, which expresses LfKctd12l, but neither LfProx1la, nor LfProx1lb. Small arrowheads in (e1’,e2’) point to β-catenin- positive nuclei. f Schemes showing the subdomain organization of river lamprey habenulae observed on transverse sections at anterior and medial levels. Color code: blue, territories expressing at least one of the two LfProx1la/b paralogs; purple, territories expressing LfKctd12l, but neither LfProx1la, nor LfProx1lb; dotted purple/blue, territories expressing both LfKctd12l and LfProx1lb. Each ISH and IHC experiment was replicated on at least three different specimens with the same results. Abbreviations: Hb, habenula; hc, habenular commissure; L, left; R, right. Scale bar = 100 µm.