Figure 2.

Development of mechanosensory neurons. Confocal projections of elav.GAL4, UAS::cd8GFP pupal abdomens showing segments A1-A4. (a) At 26.5 h APF, abdominal peripheral nerve (pink arrowhead) can be seen in each hemisegment. (b) At 29 h APF, cells expressing GFP have appeared laterally amongst the histoblasts that are migrating dorsally. The red square marks the area shown in detail in (c): note the GFP-positive cell pairs oriented in the AP axis (yellow arrows), the peripheral abdominal nerve (pink arrowhead), a cell body of a md neuron [47] (yellow arrowhead) and a motorneuron axon (green arrowhead).(d-f) 36 h APF (d), 47 h APF (e) and pharate adult (f); note the progressive elongation of the peripheral abdominal nerve towards the midline and the appearance of regularly-spaced cells that stain first weakly (yellow arrow) and then strongly (green arrows). As with all subsequent figures, anterior is up and posterior is down.