The C. elegans NeuroD homolog cnd-1 functions in multiple aspects of motor neuron fate specification

The basic helix-loop-helix transcription factor NeuroD (Neurod1) has been implicated in neuronal fate determination, differentiation and survival. Here we report the expression and functional analysis of cnd-1, a C. elegans NeuroD homolog. cnd-1 expression was first detected in neuroblasts of the AB lineage in 14 cell embryos and maintained in many neuronal descendants of the AB lineage during embryogenesis, diminishing in most terminally differentiated neurons prior to hatching. Specifically, cnd-1 reporter genes were expressed in the precursors of the embryonic ventral cord motor neurons and their progeny. A loss-of-function mutant, cnd-1(ju29), exhibited multiple defects in the ventral cord motor neurons. First, the number of motor neurons was reduced, possibly caused by the premature withdrawal of the precursors from mitotic cycles. Second, the strict correlation between the fate of a motor neuron with respect to its lineage and position in the ventral cord was disrupted, as manifested by the variable expression pattern of motor neuron fate specific markers. Third, motor neurons also exhibited defects in terminal differentiation characteristics including axonal morphology and synaptic connectivity. Finally, the expression patterns of three neuronal type-specific transcription factors, unc-3, unc-4 and unc-30, were altered. Our data suggest that cnd-1 may specify the identity of ventral cord motor neurons both by maintaining the mitotic competence of their precursors and by modulating the expression of neuronal type-specific determination factors. cnd-1 appears to have combined the functions of several vertebrate neurogenic bHLH proteins and may represent an ancestral form of this protein family.

Medienart:

Artikel

Erscheinungsjahr:

2000

Erschienen:

2000

Enthalten in:

Zur Gesamtaufnahme - volume:127

Enthalten in:

Development (Cambridge, England) - 127(2000), 19 vom: 19. Okt., Seite 4239-52

Sprache:

Englisch

Beteiligte Personen:

Hallam, S [VerfasserIn]
Singer, E [VerfasserIn]
Waring, D [VerfasserIn]
Jin, Y [VerfasserIn]

Themen:

146210-10-8
169238-82-8
Basic Helix-Loop-Helix Transcription Factors
Caenorhabditis elegans Proteins
Comparative Study
Helminth Proteins
Homeodomain Proteins
Journal Article
Muscle Proteins
Nerve Tissue Proteins
Neurogenic differentiation factor 1
Nuclear Proteins
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Transcription Factors
Unc-3 protein, C elegans
Unc-30 protein, C elegans
Unc-4 protein, C elegans

Anmerkungen:

Date Completed 01.12.2000

Date Revised 15.02.2022

published: Print

GENBANK: U10402

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM108971775