RRC ID 46594
Author Goldsmith AD, Sarin S, Lockery S, Hobert O.
Title Developmental control of lateralized neuron size in the nematode Caenorhabditis elegans.
Journal Neural Dev
Abstract BACKGROUND:Nervous systems are generally bilaterally symmetric on a gross structural and organizational level but are strongly lateralized (left/right asymmetric) on a functional level. It has been previously noted that in vertebrate nervous systems, symmetrically positioned, bilateral groups of neurons in functionally lateralized brain regions differ in the size of their soma. The genetic mechanisms that control these left/right asymmetric soma size differences are unknown. The nematode Caenorhabditis elegans offers the opportunity to study this question with single neuron resolution. A pair of chemosensory neurons (ASEL and ASER), which are bilaterally symmetric on several levels (projections, synaptic connectivity, gene expression patterns), are functionally lateralized in that they express distinct chemoreceptors and sense distinct chemosensory cues.
RESULTS:We describe here that ASEL and ASER also differ substantially in size (soma volume, axonal and dendritic diameter), a feature that is predicted to change the voltage conduction properties of the two sensory neurons. This difference in size is not dependent on sensory input or neuronal activity but developmentally programmed by a pathway of gene regulatory factors that also control left/right asymmetric chemoreceptor expression of the two ASE neurons. This regulatory pathway funnels via the DIE-1 Zn finger transcription factor into the left/right asymmetric distribution of nucleoli that contain the rRNA regulator Fibrillarin/FIB-1, a RNA methyltransferase implicated in the non-hereditary immune disease scleroderma, which we find to be essential to establish the size differences between ASEL and ASER.
CONCLUSIONS:Taken together, our findings reveal a remarkable conservation of the linkage of functional lateralization with size differences across phylogeny and provide the first insights into the developmentally programmed regulatory mechanisms that control neuron size lateralities.
Volume 5
Pages 33
Published 2010-12-1
DOI 10.1186/1749-8104-5-33
PII 1749-8104-5-33
PMID 21122110
PMC PMC3014911
MeSH Animals Animals, Genetically Modified Caenorhabditis elegans / cytology* Caenorhabditis elegans / metabolism Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Cell Size Chemoreceptor Cells / cytology* Chemoreceptor Cells / metabolism Functional Laterality / physiology* Gene Expression Regulation, Developmental* Image Processing, Computer-Assisted Metalloendopeptidases / metabolism Microscopy, Confocal Neurogenesis / physiology* Neurons / cytology Neurons / metabolism Transcription Factors / genetics
IF 2.63
Times Cited 14
WOS Category NEUROSCIENCES DEVELOPMENTAL BIOLOGY
Resource
C.elegans tm563