Evolution of neuronal anatomy and circuitry in two highly divergent nematode species

eLife

Metta Riebesell¹  Luisa Cochella²  Steven J Cook²  Bogdan Sieriebriennikov²  Ray L Hong²  Daniel J Bumbarger²  Oliver Hobert²  Ralf J Sommer³  Heather R Carstensen³  Eduardo Moreno⁴  Tahmineh Sarpolaki⁴  Jessica Castrejon⁵ 

[1] Department of Biology, California State University, Northridge, Northridge, United States;Department for Integrative Evolutionary Biology, Max-Planck Institute for Developmental Biology, Tuebingen, Germany;Department of Biological Sciences, Columbia University, New York, United States;Department of Biology, California State University, Northridge, Northridge, United States;Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria;

关键词: neuroanatomy;    Pristionchus pacificus;    chemosensory;    neural circuitry;    nematode;    electron microscopy;   

DOI  :  10.7554/eLife.47155

来源: DOAJ

【 摘 要 】

The nematodes C. elegans and P. pacificus populate diverse habitats and display distinct patterns of behavior. To understand how their nervous systems have diverged, we undertook a detailed examination of the neuroanatomy of the chemosensory system of P. pacificus. Using independent features such as cell body position, axon projections and lipophilic dye uptake, we have assigned homologies between the amphid neurons, their first-layer interneurons, and several internal receptor neurons of P. pacificus and C. elegans. We found that neuronal number and soma position are highly conserved. However, the morphological elaborations of several amphid cilia are different between them, most notably in the absence of ‘winged’ cilia morphology in P. pacificus. We established a synaptic wiring diagram of amphid sensory neurons and amphid interneurons in P. pacificus and found striking patterns of conservation and divergence in connectivity relative to C. elegans, but very little changes in relative neighborhood of neuronal processes. These findings demonstrate the existence of several constraints in patterning the nervous system and suggest that major substrates for evolutionary novelty lie in the alterations of dendritic structures and synaptic connectivity.

【 授权许可】

Unknown