§ Department of Genetics, University of Cambridge, Downing St., Cambridge, CB2 3EH. E.mail, (STS) ss2@mole.bio.cam.ac.uk, # Deaprtment of Zoology, University of Cambridge, New Museums Site, Downing Street, Cambridge, CB2 3EH,
During a behavioural screen employing crosses between 400 P[GAL4] lines and UAS-tetanus toxin light chain (TeTxLC, which abolishes synaptic vesicle release), a cross between one P[GAL4] line and UAS-TeTxLC produced a fly which eclosed but subsequently failed to mature further. These flies were unable to inflate their wings, excrete their meconium, sclerotise their cuticle or straighten their metathoracic legs. Many of these processes are thought to be mediated by neuropeptide hormones such as cardioacceloratory peptide (CAP; implicated in control of wing inflation and meconium excretion) and bursicon (implicated in cuticle sclerotisation). These neuropeptide hormones may in turn be under the control of eclosion hormone which triggers the performance of ecdysis behaviours. We postulated that inhibition of secretion of a neuropeptide hormone or hormones may be the cause of the observed phenotype of these 'juvenile' flies. We undertook a characterisation of the TeTxLC expression pattern in the CNS of these flies to assess the extent of expression. The expression pattern of P[GAL4]76 was primarily limited to a subset of the mushroom body fibres, two cell bodies in the cephalic ganglion (between the optic lobes and the central brain, at the posterior surface) and four large cells which lie in the posterior ventral region of the abdominal ganglion. We then screened through a panel of anti-neuropeptide antisera to ascertain whether any of the expression patterns of candidate neuropeptide hormones co-localised with the TeTxLC expression pattern. Here, we present a description of these 'hormonally challenged' flies, a characterisation of the TeTxLC expression pattern and a co-localisation of a neuropeptide hormone expression pattern coincident with the TeTxLC expression pattern.