Drosophila Late Pupa Indirect Flight Muscle (IFM) Dissection: A Method for High-Throughput Tissue Collection

- In the adult fly, the indirect flight muscles, or IFMs, are the fly's largest muscles spanning the entire thorax. The IFMs orchestrate the characteristic high frequency wing movements in two-winged flies, including Drosophila. Two opposing muscle fiber groups comprise the IFMs.

First, the dorsal longitudinal muscles, or DLMs, are located along the median plane of the thorax above the gut and span from anterior to posterior. Second, the dorsal ventral muscles, or DVMs, span from the top to the bottom of the thorax and are flanked by the TDT, or jump muscle. Both muscle groups are attached to the cuticle.

By about 48 hours after puparium formation, or APF, maturing IFMs can be visually identified with a simple dissection microscope. In the example protocol, we will collect IFMs from pupae older than 48 hours APF for high throughput analysis.

- For IFM dissection after 48 hours APF, use a lightly wetted paint brush to transfer the staged pupae onto a strip of double-sided sticky tape mounted on a microscope slide. Orient the pupae in a line, ventral side down, and anterior toward the bottom of the slide. When all of the pupae have been placed, use forceps to tease apart and open the