Development and morphology of the clock-gene-expressing lateral neurons of Drosophila melanogaster

J Comp Neurol. 2007 Jan 1;500(1):47-70. doi: 10.1002/cne.21146.


The clock-gene-expressing lateral neurons are essential for the locomotor activity rhythm of Drosophila melanogaster. Traditionally, these neurons are divided into three groups: the dorsal lateral neurons (LN(d)), the large ventral lateral neurons (l-LN(v)), and the small ventral lateral neurons (s-LN(v)), whereby the latter group consists of four neurons that express the neuropeptide pigment-dispersing factor (PDF) and a fifth PDF-negative neuron. So far, only the l-LN(v) and the PDF-positive s-LN(v) have been shown to project into the accessory medulla, a small neuropil that contains the circadian pacemaker center in several insects. We show here that the other lateral neurons also arborize in the accessory medulla, predominantly forming postsynaptic sites. Both the l-LN(v) and LN(d) are anatomically well suited to connect the accessory medullae. Whereas the l-LN(v) may receive ipsilateral photic input from the Hofbauer-Buchner eyelet, the LN(d) invade mainly the contralateral accessory medulla and thus may receive photic input from the contralateral side. Both the LN(d) and the l-LN(v) differentiate during midmetamorphosis. They do so in close proximity to one another and the fifth PDF-negative s-LN(v), suggesting that these cell groups may derive from common precursors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Animals, Genetically Modified
  • Brain / cytology
  • CLOCK Proteins
  • DNA-Binding Proteins / deficiency
  • Drosophila Proteins / deficiency
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / cytology*
  • Embryo, Nonmammalian
  • Gene Expression Regulation / physiology*
  • Green Fluorescent Proteins / metabolism
  • Immunohistochemistry
  • Neural Pathways / growth & development
  • Neural Pathways / metabolism
  • Neurons / classification
  • Neurons / physiology*
  • Neuropeptides / metabolism
  • Transcription Factors / deficiency
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Clk protein, Drosophila
  • DNA-Binding Proteins
  • Drosophila Proteins
  • Neuropeptides
  • Transcription Factors
  • disco protein, Drosophila
  • pdf protein, Drosophila
  • Green Fluorescent Proteins
  • CLOCK Proteins