Les facteurs de transcription Onecut contrôlent le développement de noyaux catécholaminergiques dans l'encéphale

The Onecut (OC) transcription factors are implicated in several biological processes, in particular in cellular differentiation. They are widely expressed in the CNS during embryonic development. We have investigated their roles in the development of two catecholaminergic populations: the dopaminergic A13 nucleus wherein they are expressed throughout embryonic development and the main noradrenergic population in the CNS, the Locus Coeruleus (LC), in which they are only transiently expressed at early stages. The OC factors are required for the development of both populations. They are involved, in a cell-autonomous way, in the gathering of the A13 nucleus neurons and in their maintenance and they are necessary for the proper migration and the maintenance of the LC neurons. On top of that, they cell-autonomously control the production of the neurons of a population adjacent to the LC, the rhombencephalic portion of the mesencephalic trigeminal nucleus (MTN). During embryonic development, the MTN could sustain the migration and/or maintenance of the LC neurons. Therefore, we propose that the OC factors regulate, in a non cell-autonomus mannner, the development of the LC. Hence, the OC factors are involved in the development of two catecholaminergic populations, the A13 nucleus and the LC following two different mechanisms. The roles of the OC factors in the catecholaminergic populations development and more generally in the CNS seems multiple and context-dependant.