Neurogenin3 restricts serotonergic neuron differentiation to the hindbrain

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Neuronal diversity is crucial for nervous system development.
• Dorsoventral signaling is key for neuronal diversity in the embryonic neural tube.
• Rostrocaudal organization of neuronal cell types is less understood.

Purpose of the Study:

• To investigate the role of Neurogenin3 (Neurog3) in specifying neuronal cell types along the rostrocaudal axis.
• To understand how equivalent progenitors produce distinct neuronal subtypes in hindbrain and spinal cord.

Main Methods:

• Gain- and loss-of-function experiments in chick and mouse embryos.
• Analysis of transcription factor expression (Neurog3, Ascl1).
• Investigated the role of Hes proteins in Neurog3-mediated repression.

Main Results:

• Neurogenin3 (Neurog3) expression in the spinal cord specifies p3-derived neurons.
• Neurog3 switches ventral progenitors from a serotonergic to a V3 differentiation program.
• Neurog3 represses Ascl1 in spinal p3 progenitors via Hes proteins, establishing the posterior serotonergic boundary.

Conclusions:

• Neurogenin3 (Neurog3) actively suppresses serotonergic specification in the spinal cord.
• This mechanism explains how identical p3 progenitors generate distinct neuronal cell types in the hindbrain and spinal cord.
• Highlights the role of Neurog3 in rostrocaudal patterning of neuronal diversity.