(A) Heatmap depicting the expression of homeodomain encoding genes (columns) across n=537 single twitlow MNs for which spatial mapping information was available (rows). Rows and columns are arranged by hierarchical clustering. Normalized expression levels are color-coded. Arrows indicate selected clusters for follow up studies (see Fig 1D). Hox gene expression in individual cells as identified by scRNA-Seq is shown on the left by colored bars, clusters 1 to 60 expressing specific combinations of homeodomain genes are shown on the left. 