The development of the vertebrate nervous system requires the generation of a large number of different types of neurons, characterized by the specific expression of neurotransmitters and their receptors and by the formation of highly specific axonal connections. These developmental processes are regulated in part by transcription factors that bind to specific DNA sequences and activate or repress the expression of neural genes. These fundamental mechanisms, used throughout the nervous system, are relevant to understanding the developmental basis of mental disorders such as schizophrenia and autism, and congenital neurological diseases. Transcriptional regulation of neural cell fate is also directly relevant to stem cell biology and the application of regenerative medicine to diseases of the brain. In prior work using transgenic mice we have shown that the POU- homeodomain factor Brn3a is required for the proper development of sensory neurons of the trigeminal and dorsal root ganglia. Brn3a governs a program of gene expression which includes the repression of early neurogenic genes and the activation of late genes that determine sensory subtypes. We also have recently shown that the LIM-homeodomain factor Islet1 regulates a gene expression program overlapping that of Brn3a, suggesting that these two factors mediate a critical transition in sensory development from proliferation and lineage determination to terminal differentiation. Our microarray studies of sensory ganglia have implicated several other transcription factors in sensory development, one of which, Hmx1, is examined in detail in this proposal.
The Specific Aims of this project will be: 1) Further define the gene regulatory program of the sensory ganglia by examining neuronal survival, axon growth and targeting, and global gene expression in mice which are double mutants for Brn3a and Islet1, and explore epigenetic mechanisms which may restrict the activity of Brn3a and Islet1. 2) Determine the role of the homeodomain factor Hmx1 in the development of the major subdivisions of the trigeminal ganglion, and the gene expression program regulated by Hmx1. 5.

Public Health Relevance

This is a basic research proposal examining the role of specific homeodomain transcription factors in neural development, using mouse sensory neurons as a model system. Such studies are essential to understanding developmental brain disorders such as schizophrenia, autism and congenital neurological diseases, and for the application of stem cell-based regenerative medicine to diseases of the brain.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
2R01NS064933-06A2
Application #
7729799
Study Section
Neurogenesis and Cell Fate Study Section (NCF)
Program Officer
Riddle, Robert D
Project Start
2009-09-30
Project End
2011-08-31
Budget Start
2009-09-30
Budget End
2010-08-31
Support Year
6
Fiscal Year
2009
Total Cost
$524,184
Indirect Cost
Name
Seattle Children's Hospital
Department
Type
DUNS #
048682157
City
Seattle
State
WA
Country
United States
Zip Code
98105
Huang, Siyi; O'Donovan, Kevin J; Turner, Eric E et al. (2015) Extrinsic and intrinsic signals converge on the Runx1/CBF? transcription factor for nonpeptidergic nociceptor maturation. Elife 4:e10874
Cox, Timothy C; Camci, Esra D; Vora, Siddharth et al. (2014) The genetics of auricular development and malformation: new findings in model systems driving future directions for microtia research. Eur J Med Genet 57:394-401
Quina, Lely A; Tempest, Lynne; Hsu, Yun-Wei A et al. (2012) Hmx1 is required for the normal development of somatosensory neurons in the geniculate ganglion. Dev Biol 365:152-63
Quina, Lely A; Kuramoto, Takashi; Luquetti, Daniela V et al. (2012) Deletion of a conserved regulatory element required for Hmx1 expression in craniofacial mesenchyme in the dumbo rat: a newly identified cause of congenital ear malformation. Dis Model Mech 5:812-22
Dykes, Iain M; Tempest, Lynne; Lee, Su-In et al. (2011) Brn3a and Islet1 act epistatically to regulate the gene expression program of sensory differentiation. J Neurosci 31:9789-99
Wang, Shirong; Turner, Eric E (2010) Expression of dopamine pathway genes in the midbrain is independent of known ETS transcription factor activity. J Neurosci 30:9224-7
Lanier, Jason; Dykes, Iain M; Nissen, Stephanie et al. (2009) Brn3a regulates the transition from neurogenesis to terminal differentiation and represses non-neural gene expression in the trigeminal ganglion. Dev Dyn 238:3065-79
Quina, Lely A; Wang, Shirong; Ng, Lydia et al. (2009) Brn3a and Nurr1 mediate a gene regulatory pathway for habenula development. J Neurosci 29:14309-22