Fig. 3. max-2 expression is dynamic and is required cell autonomously for dorsal commissure guidance. (A-E) The expression pattern of max-2 from znex135[Pmax-2::GFP] transgenic animals. Promoter element (5'-3') contains the 5 kb region from 5557 to 262 on cosmid F18A11. (A-C) At the comma and later embryonic stages, GFP expression is mainly in the anterior region of the embryo and along the ventral cord. (D) After hatching, GFP is expressed in the pharynx and several head and tail neurons. Expression of GFP in the ALM neurons (arrow) and the postembryonic PVD neuron can also be seen. (E) A young adult animal, showing GFP expression in the postembryonic AVM neuron (arrow and left inset) and the elaborate dendritic connections of a mature PVD neuron (right inset). (F) A max-2 cDNA expressed in the DD and VD motoneurons cell-autonomously rescues the max-2(cy2) defects in these neurons. For the Punc-25::max-2 rescue, the data presented are the combined data from four independently generated transgenic lines. A Punc-47::max-2 rescue line (znex133) and its non transgenic siblings (znex133 sibs) are also shown here. The unc-25 promoter used for this experiment contained 2 kb of the 5' region through the start codon. The unc-47 promoter used for this experiment contained 1.7 kb of the region 5' to the start codon through the 50th codon. The numbers (n) of animals used for each experiment are shown; bars represent the standard error in F. Asterisks indicate a P-value of less than 0.001 (Student's t-test). In all pictures, anterior is to the left and dorsal is up. Scale bar: 10 µm.