Pigment-dispersing factor (Pdf) signaling in the circadian system of Caenorhabditis elegans

HERRERO, A; ROMANOWSKI, A; MEELKOP, E; GOLOMBEK, DA

GENES BRAIN AND BEHAVIOR

WILEY-BLACKWELL PUBLISHING, INC

Año: 2015 vol. 14 p. 493 - 501

1601-1848

The neuropeptide pigment-dispersing factor (PDF) is important for the generation and entrainment of circa- dian rhythms in the fruitfly Drosophila melanogaster. Recently two pdf homologs, pdf-1 and pdf-2, and a PDF receptor, pdfr-1, have been found in Caenorhabditis ele- gans and have been implicated in locomotor activity. In this work, we have studied the role of the PDF neuropep- tide in the circadian system of C. elegans and found that both pdf-1 and pdf-2 mutants affect the normal locomo- tor activity outputs. In particular, loss of pdf-1 induced circadian arrhythmicity under both light?dark (LD) and constant dark (DD) conditions. These defects can be res- cued by a genomic copy of the pdf-1 locus. Our results indicate that PDF-1 is involved in rhythm generation and in the synchronization to LD cycles, as rhythmic pat- terns of activity rapidly disappear when pdf-1 mutants are recorded under both entrained and free-running con- ditions. The role of PDF-2 and the PDF receptors is prob- ably more complex and involves the interaction between the two pdf paralogues found in the nematode.