Dynamic expression of transcription factor Brn3b during mouse cranial nerve development. Issue 5 (29th September 2015)

• Record Type: Journal Article
• Authors: Sajgo, Szilard; Ali, Seid; Popescu, Octavian; Badea, Tudor Constantin
• Is Part Of: Journal of comparative neurology. Volume 524:Issue 5(2016)
• Page Start: 1033
• Page End: 1061
• Publication Date: 2015-09-29
• Subjects: cranial nerves -- transcription -- optic nerve -- trigeminal nerve -- facial nerve -- glossopharyngeal nerve -- vagus nerve -- POU domain Brn3b; Comparative neurobiology -- Periodicals; Neurology -- Periodicals; 616
• DOI: 10.1002/cne.23890
• Languages: English
• ISSNs: 0021-9967

Abstract

ABSTRACT: During development, transcription factor combinatorial codes define a large variety of morphologically and physiologically distinct neurons. Such a combinatorial code has been proposed for the differentiation of projection neurons of the somatic and visceral components of cranial nerves. It is possible that individual neuronal cell types are not specified by unique transcription factors but rather emerge through the intersection of their expression domains. Brn3a, Brn3b, and Brn3c, in combination with each other and/or transcription factors of other families, can define subgroups of retinal ganglion cells (RGC), spiral and vestibular ganglia, inner ear and vestibular hair cell neurons in the vestibuloacoustic system, and groups of somatosensory neurons in the dorsal root ganglia. The present study investigates the expression and potential role of the Brn3b transcription factor in cranial nerves and associated nuclei of the brainstem. We report the dynamic expression of Brn3b in the somatosensory component of cranial nerves II, V, VII, and VIII and visceromotor nuclei of nerves VII, IX, and X as well as other brainstem nuclei during different stages of development into adult stage. We find that genetically identified Brn3b KO RGC axons show correct but delayed pathfinding during the early stages of embryonic development. However, loss of Brn3b does not affect the anatomy of the other cranial nerves normally expressing this transcription factor. J. Comp. Neurol. 524:1033–1061, 2016. © 2015 Wiley Periodicals, Inc. Abstract : We use combinatorial genetic strategies to define the dynamic expression of the transcription factor Brn3b in developing mouse cranial nerves. The involvement of Brn3b in the transcriptional code for projection sensory neurons has implications for the evolution and development of neuronal cell types.