Global knockdown of Daam1a affects the formation of habenular neuropil and axonal efferent connectivity to the IPN. (A-O) Dorsal views of the habenular region (A-J) and IPN (K-O) of Tg(pou4f1-hsp70l:GFP) zebrafish at 4.5 dpf, with anterior to the top. The habenular neuropil was immunostained against acetylated α-tubulin (A-E, white), whereas the soma (F-J) and efferent projections (K-O) of dorsal habenular neurons expressing pou4f1-hsp70l:GFP were labelled in vivo (green). Defects in the Hb and IPN induced by injection of daam1a-MO were classified as ‘normal’, ‘mild’, ‘moderate’ or ‘severe’ phenotypes (columns 1-4). Column 5 (rescue) corresponds to the phenotypes observed after co-expression of daam1a-MO and hDAAM1 mRNA. All images are maximum intensity z-stack confocal projections. Vertical dotted brackets in A-E indicate the extent of habenular neuropil in the left Hb. Asterisks in F-J indicate the enlarged cellular domain of the Hb expressing pou4f1-hsp70l:GFP. (P,Q) Distribution of the different phenotypes of habenular neuropil (P) and efferent connectivity to the IPN (Q) in Co-MO, daam1a-MO and rescue conditions. Data are presented as the percentage of total larvae showing the indicated phenotype. L, left; LHb, left Hb; R, right; RHb, right Hb. Scale bars: 20 μm.
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