PT  - JOURNAL ARTICLE
AU  - Perez, Lillian M.
AU  - Alfonso, Aixa
TI  - The Conserved ASCL1/MASH-1 Ortholog HLH-3 Specifies Sex-Specific Ventral Cord Motor Neuron Fate in <em>Caenorhabditis elegans</em>
AID  - 10.1534/g3.120.401458
DP  - 2020 Nov 01
TA  - G3: Genes|Genomes|Genetics
PG  - 4201--4213
VI  - 10
IP  - 11
4099  - http://www.g3journal.org/content/10/11/4201.short
4100  - http://www.g3journal.org/content/10/11/4201.full
AB  - Neural specification is regulated by one or many transcription factors that control expression of effector genes that mediate function and determine neuronal type. Here we identify a novel role for one conserved proneural factor, the bHLH protein HLH-3, implicated in the specification of sex-specific ventral cord motor neurons in C. elegans. Proneural genes act in early stages of neurogenesis in early progenitors, but here, we demonstrate a later role for hlh-3. First, we document that differentiation of the ventral cord type C motor neuron class (VC) within their neuron class, is dynamic in time and space. Expression of VC class-specific and subclass-specific identity genes is distinct through development and is dependent on the VC position along the A-P axis and their proximity to the vulva. Our characterization of the expression of VC class and VC subclass-specific differentiation markers in the absence of hlh-3 function reveals that VC fate specification, differentiation, and morphology requires hlh-3 function. Finally, we conclude that hlh-3 cell-autonomously specifies VC cell fate.