Neurogenesis in the crustacean ventral nerve cord: homology of neuronal stem cells in Malacostraca and Branchiopoda?

ABSTRACTThe Drosophila ventral nerve cord (VNC), the fly equivalent of the spinal cord, is composed of thousands of neurons that are born from a set of individually identifiable stem cells. The VNC harbors neuronal circuits required for the execution of vital behaviors, such as flying and walking. Taking advantage of the lineage-based functional organization of the VNC and genetic tools we developed, we investigated the molecular and developmental basis of behavior by focusing on lineage-specific functions of the homeodomain transcription factor, Unc-4. We found that Unc-4 functions in lineage 11A to promote cholinergic neurotransmitter identity and suppress the GABA fate. In 7B lineage, Unc-4 promotes proper neuronal projections to the leg neuropil, the hub for leg-related neuronal circuits and a specific flight-related take-off behavior. We also uncovered that Unc-4 acts peripherally to promote the development of proprioceptive sense organs and the abilities of flies to execute specific leg-related behaviors such as walking, climbing, and grooming. Our findings, thus, initiates the work on revealing molecular and developmental events that shape the VNC related behaviors.

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Unc-4 acts to promote neuronal identity and development of the take-off circuit in the Drosophila CNS

eLife ◽

10.7554/elife.55007 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 4

Author(s):

Haluk Lacin ◽

W Ryan Williamson ◽

Gwyneth M Card ◽

James B Skeath ◽

James W Truman

Keyword(s):

Stem Cells ◽

Transcription Factor ◽

Nerve Cord ◽

Molecular Basis ◽

Ventral Nerve Cord ◽

Functional Organization ◽

Time Dependent ◽

Knock Out ◽

Neuronal Identity ◽

Cholinergic Neurotransmitter

The Drosophila ventral nerve cord (VNC) is composed of thousands of neurons born from a set of individually identifiable stem cells. The VNC harbors neuronal circuits required to execute key behaviors, such as flying and walking. Leveraging the lineage-based functional organization of the VNC, we investigated the developmental and molecular basis of behavior by focusing on lineage-specific functions of the homeodomain transcription factor, Unc-4. We found that Unc-4 functions in lineage 11A to promote cholinergic neurotransmitter identity and suppress the GABA fate. In lineage 7B, Unc-4 promotes proper neuronal projections to the leg neuropil and a specific flight-related take-off behavior. We also uncovered that Unc-4 acts peripherally to promote proprioceptive sensory organ development and the execution of specific leg-related behaviors. Through time-dependent conditional knock-out of Unc-4, we found that its function is required during development, but not in the adult, to regulate the above events.

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Extracellular filaments in the perineurium of the florida lobster, Panulirus argus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128237 ◽

1987 ◽

Vol 45 ◽

pp. 784-785

Author(s):

Roy J. Baerwald ◽

Lura C. Williamson

Keyword(s):

Blood Brain Barrier ◽

Glial Cells ◽

Tannic Acid ◽

Nerve Cord ◽

Ventral Nerve Cord ◽

Florida Keys ◽

Panulirus Argus ◽

Brain Barrier ◽

Cacodylate Buffer ◽

Nerve Cords

In arthropods the perineurium surrounds the neuropile, consists of modified glial cells, and is the morphological basis for the blood-brain barrier. The perineurium is surrounded by an acellular neural lamella, sometimes containing scattered collagen-like fibrils. This perineurial-neural lamellar complex is thought to occur ubiquitously throughout the arthropods. This report describes a SEM and TEM study of the sheath surrounding the ventral nerve cord of Panulirus argus.Juvenile P. argus were collected from the Florida Keys and maintained in marine aquaria. Nerve cords were fixed for TEM in Karnovsky's fixative and saturated tannic acid in 0.1 M Na-cacodylate buffer, pH = 7.4; post-fixed in 1.0% OsO4 in the same buffer; dehydrated through a graded series of ethanols; embedded in Epon-Araldite; and examined in a Philips 200 TEM. Nerve cords were fixed for SEM in a similar manner except that tannic acid was not used.

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Visualization of NO-producible neurons and NO production in the ventral nerve cord of the earthworm

Neuroscience Research ◽

10.1016/s0168-0102(00)81192-x ◽

2000 ◽

Vol 38 ◽

pp. S58

Author(s):

Y Kitamura

Keyword(s):

Nerve Cord ◽

Ventral Nerve Cord ◽

No Production

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Faculty Opinions recommendation of Immunoglobulin-domain proteins required for maintenance of ventral nerve cord organization.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1004347.50306 ◽

2002 ◽

Author(s):

Jonathan Hodgkin

Keyword(s):

Nerve Cord ◽

Ventral Nerve Cord ◽

Immunoglobulin Domain

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Mutations Affecting Nerve Attachment of Caenorhabditis elegans

Genetics ◽

10.1093/genetics/157.4.1611 ◽

2001 ◽

Vol 157 (4) ◽

pp. 1611-1622 ◽

Cited By ~ 1

Author(s):

Go Shioi ◽

Michinari Shoji ◽

Masashi Nakamura ◽

Takeshi Ishihara ◽

Isao Katsura ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Nerve Cord ◽

Ventral Nerve Cord ◽

Body Wall ◽

The Body ◽

Genetic Loci ◽

Muscle Attachment ◽

C Elegans ◽

Ventral Cord ◽

Excretory Canal

Abstract Using a pan-neuronal GFP marker, a morphological screen was performed to detect Caenorhabditis elegans larval lethal mutants with severely disorganized major nerve cords. We recovered and characterized 21 mutants that displayed displacement or detachment of the ventral nerve cord from the body wall (Ven: ventral cord abnormal). Six mutations defined three novel genetic loci: ven-1, ven-2, and ven-3. Fifteen mutations proved to be alleles of previously identified muscle attachment/positioning genes, mup-4, mua-1, mua-5, and mua-6. All the mutants also displayed muscle attachment/positioning defects characteristic of mua/mup mutants. The pan-neuronal GFP marker also revealed that mutants of other mua/mup loci, such as mup-1, mup-2, and mua-2, exhibited the Ven defect. The hypodermis, the excretory canal, and the gonad were morphologically abnormal in some of the mutants. The pleiotropic nature of the defects indicates that ven and mua/mup genes are required generally for the maintenance of attachment of tissues to the body wall in C. elegans.

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