Neuropeptide Gene Families in the Nematode Caenorhabditis elegans^a

Abstract

Neuropeptides have diverse roles in the function and development of the nervous system. With the completion of the sequencing of the C. elegans genome, rapid identification of nematode neuropeptide genes is possible. To date, 41 C. elegans neuropeptide genes have been identified. Of these genes, 20 genes, named flp (FMRFamide-like peptide) genes, encode FMRFamide-related proteins (FaRPs). Deletion of one of the flp genes, flp-1, results in several behavioral defects, suggesting that at least one flp gene is not functionally redundant with other flp genes. Twenty-one genes, named neuropeptide-like protein (nlp) genes, encode peptides distinct from the FaRP family. The predicted nlp-1 and nlp-2 neuropeptides have modest similarity to buccalin and myomodulin, respectively. Cellular expression patterns and genetic analysis of flp and nlp genes suggest that neuropeptides in nematodes also have widespread and varied roles in nervous system function.

HLH-14 is aC. elegansAchaete-Scute protein that promotes neurogenesis through asymmetric cell division

“…With the PHB-specific neuropeptide-like promoter fusion nlp-1::gfp (Li et al, 1999), we found that hlh-14 mutants lacked PHB neurons. With the PHA-specific promoter fusions flp-15::gfp (Li et al, 1999) and osm-10::gfp ) (PHA-specific in adults), we found no alteration in the number of PHA neurons in hlh-14 mutants.…”

“…LG III gmIs12 [srb-6::gfp] (N. Hawkins, personal communication) (Troemel et al, 1995), gmIs21[nlp-1::gfp] (Li et al, 1999).…”

“…The srb-6::gfp reporter (Troemel et al, 1995), which was integrated onto LG III to form the strain gmIs12 (N. Hawkins, personal communication), detected both the PHA and PHB phasmid neurons. The nlp-1::gfp reporter (Li et al, 1999) gmEx285 was integrated onto LG III and LG V to form the arrays gmIs21 and gmIs22, respectively; these arrays specifically detected the PHB neurons. The PHA neurons were detected using the flp-15::gfp reporter ynIs45 (Li et al, 1999) and the osm-10::gfp reporter nuIs11 ) (PHA-specific in adults).…”

“…The nlp-1::gfp reporter (Li et al, 1999) gmEx285 was integrated onto LG III and LG V to form the arrays gmIs21 and gmIs22, respectively; these arrays specifically detected the PHB neurons. The PHA neurons were detected using the flp-15::gfp reporter ynIs45 (Li et al, 1999) and the osm-10::gfp reporter nuIs11 ) (PHA-specific in adults). The PVQ neurons were detected using the sra-6::gfp reporter kyIs39 (Troemel et al, 1995).…”

Molecular cloning and functional expression of the first insect FMRFamide receptor

“…FMRFamide-related peptides may act excitatory or inhibitory on their target cells (depending on the target cell type) and they are involved in reproduction, feeding, and many other behaviors (3,5,(14)(15)(16)(17)(18). The abundance, complexity, and importance of FMRFamide peptides within an invertebrate species, is illustrated by the fact that the nematode worm Caenorhabditis elegans contains at least 20 FMRFamide preprohormone genes, and that the deletion of only one of these genes causes severe behavioral defects (5,17,19).…”