TY - JOUR
T1 - Developmental genetics of the C. elegans pharyngeal neurons NSML and NSMR
AU - Axäng, Claes
AU - Rauthan, Manish
AU - Hall, David H.
AU - Pilon, Marc
N1 - Funding Information:
We thank the C. elegans Genetics Center (funded by the NIH Center for Research Resources) for providing many of the strains used in this study, and the Swegene Centre for Cellular Imaging at Gothenburg for the use of imaging equipment. Original annotated prints of serial section electron micrographs from the work of Albertson and Thomson [5] and White et al [9] are stored in the Hall lab at AECOM. These materials were donated to the Hall archive courtesy of Drs. Jonathan Hodgkin and John White from the MRC/LMB in Cambridge, England. This work was supported by grants to MP from the Swedish funding agencies Vetenskaprådet, Cancerfonden and Åhlens Stiftelse, and by a National Institute of Health (USA) grant to DHH.
PY - 2008
Y1 - 2008
N2 - Background. We are interested in understanding how the twenty neurons of the C. elegans pharynx develop in an intricate yet reproducible way within the narrow confines of the embryonic pharyngeal primordium. To complement an earlier study of the pharyngeal M2 motorneurons, we have now examined the effect of almost forty mutations on the morphology of a bilateral pair of pharyngeal neurosecretory-motor neurons, the NSMs. Results. A careful description of the NSM morphology led to the discovery of a third, hitherto unreported process originating from the NSM cell body and that is likely to play a proprioceptive function. We found that the three NSM processes are differently sensitive to mutations. The major dorsal branch was most sensitive to mutations that affect growth cone guidance and function (e.g. unc-6, unc-34, unc-73), while the major sub-ventral branch was more sensitive to mutations that affect components of the extracellular matrix (e.g. sdn-1). Of the tested mutations, only unc-101, which affects an adaptin, caused the loss of the newly described thin minor process. The major processes developed synaptic branches post-embryonically, and these exhibited activity-dependent plasticity. Conclusion. By studying the effects of nearly forty different mutations we have learned that the different NSM processes require different genes for their proper guidance and use both growth cone dependent and growth cone independent mechanisms for establishing their proper trajectories. The two major NSM processes develop in a growth cone dependent manner, although the sub-ventral process relies more on substrate adhesion. The minor process also uses growth cones but uniquely develops using a mechanism that depends on the clathrin adaptor molecule UNC-101. Together with the guidance of the M2 neuron, this is the second case of a pharyngeal neuron establishing one of its processes using an unexpected mechanism.
AB - Background. We are interested in understanding how the twenty neurons of the C. elegans pharynx develop in an intricate yet reproducible way within the narrow confines of the embryonic pharyngeal primordium. To complement an earlier study of the pharyngeal M2 motorneurons, we have now examined the effect of almost forty mutations on the morphology of a bilateral pair of pharyngeal neurosecretory-motor neurons, the NSMs. Results. A careful description of the NSM morphology led to the discovery of a third, hitherto unreported process originating from the NSM cell body and that is likely to play a proprioceptive function. We found that the three NSM processes are differently sensitive to mutations. The major dorsal branch was most sensitive to mutations that affect growth cone guidance and function (e.g. unc-6, unc-34, unc-73), while the major sub-ventral branch was more sensitive to mutations that affect components of the extracellular matrix (e.g. sdn-1). Of the tested mutations, only unc-101, which affects an adaptin, caused the loss of the newly described thin minor process. The major processes developed synaptic branches post-embryonically, and these exhibited activity-dependent plasticity. Conclusion. By studying the effects of nearly forty different mutations we have learned that the different NSM processes require different genes for their proper guidance and use both growth cone dependent and growth cone independent mechanisms for establishing their proper trajectories. The two major NSM processes develop in a growth cone dependent manner, although the sub-ventral process relies more on substrate adhesion. The minor process also uses growth cones but uniquely develops using a mechanism that depends on the clathrin adaptor molecule UNC-101. Together with the guidance of the M2 neuron, this is the second case of a pharyngeal neuron establishing one of its processes using an unexpected mechanism.
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U2 - 10.1186/1471-213X-8-38
DO - 10.1186/1471-213X-8-38
M3 - Article
C2 - 18400083
AN - SCOPUS:43549086414
SN - 1471-213X
VL - 8
JO - BMC Developmental Biology
JF - BMC Developmental Biology
M1 - 38
ER -