Arid3c identifies an uncharacterized subpopulation of V2 interneurons during embryonic spinal cord development

Front Cell Neurosci. 2024 Oct 16:18:1466056. doi: 10.3389/fncel.2024.1466056. eCollection 2024.

Abstract

Motor activity is organized by neuronal networks composed of motor neurons and a wide variety of pre-motor interneuron populations located in the brainstem and spinal cord. Differential expression and single-cell RNA sequencing studies recently unveiled that these populations subdivide into multiple subsets. However, some interneuron subsets have not been described yet, and the mechanisms contributing to this neuronal diversification have only been partly deciphered. In this study, we aimed to identify additional markers to further describe the diversity of spinal V2 interneuron populations. Here, we compared the transcriptome of V2 interneurons with that of the other cells of the embryonic spinal cord and extracted a list of genes enriched in V2 interneurons, including Arid3c. Arid3c identifies an uncharacterized subset of V2 that partially overlaps with V2c interneurons. These two populations are characterized by the production of Onecut factors and Sox2, suggesting that they could represent a single functional V2 unit. Furthermore, we show that the overexpression or inactivation of Arid3c does not alter V2 production, but its absence results in minor defects in locomotor execution, suggesting a possible function in subtle aspects of spinal locomotor circuit formation.

Keywords: Arid3c; V2 interneurons; V2c interneurons; embryonic spinal cord; motor activity; motor circuits.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. Work in the F.C. laboratory was supported by grants from the « Fonds spéciaux de recherche » (FSR) of the Université catholique de Louvain, by « Projet de recherche (PDR) » funding #T.0039.21 of the Fonds de la Recherche Scientifique (F.R.S.-FNRS, Belgium), by the « Actions de Recherche Concertées (ARC) » #17/22-079 of the « Direction générale de l’Enseignement non obligatoire et de la Recherche scientifique – Direction de la Recherche scientifique – Communauté française de Belgique » and granted by the « Académie universitaire ‘Louvain’ » and by the Association Belge contre les Maladies neuro-Musculaires (ABMM). E.R. held an FSR grant from the UCLouvain and a PhD grant from the “Fonds pour la Recherche dans l’Industrie et l’Agriculture » (F.R.S-FNRS), C.B. held a PhD grant from the « Fonds pour la Recherche dans l’Industrie et l’Agriculture » (F.R.S.-FNRS, Belgium). F.C. is a Research Director of the F.R.S.-FNRS.