Cellular dynamics and molecular mechanisms underlying the 3D organization and connectivity of the statoacoustic ganglion

The statoacoustic ganglion (SAG) is a complex 3D structure composed by neurons in charge of transmitting the information from inner ear hair cells to the CNS. During development, SAG copes with otic tissue demands to maintain functionality. However, SAG development in coordination with otic developm...

Descripción completa

Detalles Bibliográficos
Autor: Bañón González, Aitor
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/687790
Acceso en línea:http://hdl.handle.net/10803/687790
Access Level:acceso abierto
Palabra clave:Statoacoustic ganglion
Pioneer cells
CRISPR
Cell migration
Axonogenesis
Ganglio estatoacústico
Células pioneras
Migración celular
Axonogénesis
616.8
Descripción
Sumario:The statoacoustic ganglion (SAG) is a complex 3D structure composed by neurons in charge of transmitting the information from inner ear hair cells to the CNS. During development, SAG copes with otic tissue demands to maintain functionality. However, SAG development in coordination with otic development has not been addressed in detail. We use high resolution confocal imaging of otic neuroblasts (NB), photoconversion, photoablation, transgenic lines, CRISPR/Cas9 and Cas13 to address SAG development at the molecular and cellular levels. We find a population of pioneer SAG neurons specified outside the otic placode, which play an attracting role over delaminating NB affecting its coalescence. NB from the otic epithelium delaminate in an EMT-like manner, and non-collectively and actively migrate depending on RhoGTPases to establish the anterior SAG lobe. Followingly, NB crawl onto pioneer axons to form the posterior SAG lobe. Lack of both pioneer SAG neurons and pioneer axons alters SAG shape. Finally, we uncover the cell adhesion molecule Cntn2 and the chemokine Cxcl14 as two new molecules required for correct pioneer axon targeting to HC and posterior lobe formation. We confirm that HC and neurotrophin signaling is not required for directed axon targeting but stabilization and neuronal survival. In conclusion, SAG development is a complex process in which several mechanisms interplay, prime and scaffold further SAG developmental steps.