Worm Breeder's Gazette 9(3): 110
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
The neuropeptide FMRFamide (Phe-Met-Arg-Phe-amide) and peptides homologous to FMRFamide have been found throughout the animal kingdom where they have been implicated as neurotransmitters, neurohormones, and neuromodulators Using polyclonal antibodies raised against synthetic FMRFamide (donated by R Calabrese and T. O'Donohue) and a whole mount staining procedure modified from S McIntire, C. Desai, and R H Horvitz, we mapped the distribution of FMRFamide-like immunoreactivity in N2 adult hermaphrodites There are at least nine immunoreactive cells (some paired, some unpaired) around the nerve ring, six cells along the ventral cord, one pair of lateral cells near the position of the vulva, one cell in the dorsal-rectal ganglion, and one cell in the pre-anal ganglion In addition, the nerve ring is intensely labelled, there are numerous immunoreactive processes running throughout the length of the ventral cord (all but one of these processes run on the same side of the hypodermal ridge as the immunoreactive cells in the cord), one process, which runs the entire length of the animal, in the dorsal cord and each lateral cord, and a complex arborization of immunoreactive processes that may innervate the vulva muscles Preincubation of the antiserum with synthetic FMRFamide eliminates staining in the animal Tentative identification of many of the FMRFamide-like immunoreactive cells have been deduced from analysis of mutants and from the morphology and position of the cells. For example, the number and position of the immunoreactive cell bodies in the ventral cord corresponds to the VC motoneurons Furthermore, staining of lin-39 mutants, in which many of the VC motoneurons die, reveals fewer cell bodies and processes in the ventral cord, supporting the identification of the ventral cells as the VC motoneurons Other identified cells include the RID motoneuron, either the RIF or RIG interneurons, the DVB interneuron/motoneuron, and the PVT cell We have recently discovered that staining of neurons and processes in the cords can be optimized by using animal fragments, which are derived by gentle homogenization of formaldehyde-fixed animals This procedure has allowed more consistent visualization of immunoreactivity in two cell types, the ALA cell and the CAN cells Acetone extracts of whole animals contain 120 nmoles of FMRFamide- like peptide per gram wet weight, as measured by radioimmunoassay (RIA) The antibody displays a similar recognition to the C. s) and to synthetic FMRFamide Based on antibody specificities (Marder et al , 1986) these data suggest that the antigen(s) contains at least a terminal -ArgPhe-amide We intend to purify and sequence the FMRFamide-like peptide(s) from C elegans.We are continuing to screen unc mutants to identify animals that have FMRFamide-related defects or that are FMRFamide-deficient. In addition, we are examining target cell (vulval muscles) influences on the induction or stabilization of (VC and PVT) processes in Vulvaless, Multi vulva, and Egghead mutants We will confirm that the CAN cells contain FMRFamide by examining vab-8 mutants, which have misplaced CAN cells. The CAN cells are believed to be secretory cells and have been shown to be critical for the survival of young animals and for the proper development of the posterior half of the animal (J Sulston and J. Hodgkin, WBG 5(1), 1980) . As neuropeptides function as neurohormones in many instances, the FMRFamidelike peptide may be one of the neurohormones secreted by the CAN cells during the development of the animal; animals that lack FMRFamide may have a phenotype similar to animals that have CAN cell- related defects Lastly, we have obtained an APlysia cDNA clone encoding FMRFamide from R Scheller Using this Aplysia clone to probe a C. lambda library (a gift from S Emmons), we have isolated two positive clones, which will be subcloned and