Fig. 7

Neurobeachin Is Required Autonomously to Maintain Dendritic Complexity

(A–C) Cross-section views of individual chimeric larvae containing GFP-marked cells from M/CoLo:GFP embryos in unmarked hosts at 6 dpf. Images are maximum-intensity projections of <20 µm from digitally rendered cross-sections. For clarity, fluorescence signal outside of the GFP-labeled neurons has been digitally removed. Ventral is down, lateral is to the left. Scale bar represents 10 µm. Larvae are stained for GFP (magenta), Cx36 (yellow), and GlyR (cyan). The GFP channel is shown in neighboring panels.

(A) In wild-type (wt>wt), M elaborates complex dendrites with three main compartments: ventral (arrow), lateral (arrowhead), and somatic (double arrowhead).

(B) When M is nbea mutant in an otherwise wild-type host (nbea>wt), the M dendrites lose the fine terminal branches of the dendritic arbor.

(C) When M is wild-type in a nbea mutant host (wt>nbea), the dendritic complexity is similar to wild-type.

(D–G) Quantitation of M ventral dendrite parameters in chimeric embryos.

(H–K) Quantitation of changes in the ventral dendrite from 1 to 5 dpf in wild-type and nbea mutant embryos. “Longest path” is the longest continuous main path from cell body to dendrite tip. “Total length” is the sum of the lengths of all the dendritic branches. “Branches” is the sum of the number of branches made off of the main, longest branch. “Branch depth” is the maximum depth of branching, with the main branch being primary and all subsequent branches being labeled sequentially.

Graphs in (D)–(K) represent data as mean ± SEM. p < 0.001 compared to control; ns, not significant.

Associated experimental statistics are found in Table S5.