Antibodies against the PER protein of Drosophila label neurons in the optic lobe, central brain, and thoracic ganglia of the crickets Teleogryllus commodus and Teleogryllus oceanicus.

We describe labeling of neurons in the central nervous system of two cricket species, Teleogryllus commodus and T. oceanicus, with both mono- and polyclonal antibodies against the PER protein. Western blots reveal that the monoclonal antibodies recognize a single protein with a molecular weight of approximately 94 kDa, i.e., similar to that of the PER protein of the moth, Anterea pernii. Neurons and their processes are labeled both in the optic lobes and in the central brain. Processes occur in the accessory medulla, the medulla, and proximal lamina, in the central complex, in the non-glomerular neuropil, and in the retrocerebral complex, suggesting that PER-containing neurons form a widely distributed network. Neurons and processes were also labeled in the meso- and metathoracic ganglia. Four to six PER-immunoreactive (ir) neurons with processes in the accessory medulla were double labeled by an antibody against pigment-dispersion factor (PDF), a peptide that is implicated in circadian rhythmicity in Drosophila. In the central brain, projections of fibers labeled by the anti-PER and anti-PDF antibodies were mainly distinct, with overlap only in a few restricted regions. In most neurons, including those projecting into the accessory medulla, PER labeling was restricted to the cytoplasm and there was no indication of circadian variation in the intensity of staining.