A Single-Nucleus Transcriptomic Atlas of the Mouse Lumbar Spinal Cord: Functional Implications of Non-Coding RNAs

The adult lumbar spinal cord plays a critical role in locomotor control and somatosensory integration, yet its transcriptional architecture remains incompletely characterized under physiological conditions. Here, we present an integrative single-nucleus RNA se-quencing (snRNA-seq) atlas of the healthy adult mouse lumbar spinal cord, assembled from over 86,000 nuclei across five public datasets. Using a harmonized computational pipeline, we identify all major spinal cell lineages and resolve 17 transcriptionally distinct neuronal subtypes. A central novelty of our approach is the systematic inclusion of non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and pseudogenes. By comparing transcriptomic analyses based on coding-only, non-coding-only, and combined gene sets, we demonstrate that ncRNAs contribute cell type-specific signatures that enhance neuronal subtype resolution. Differential expression analysis highlights lineage-associated ncRNAs enriched in sensory, inhibitory, and ependymal populations. This resource offers a high-resolution, ncRNA-inclusive refer-ence for the adult spinal cord and provides a foundation for future studies on spinal plasticity, injury, and regeneration.