Fig. 6.

He larvae retain ancestral sea urchin larval neural cell types as well as acquire the expression of several putative adult neural cell types. (A) UMAP of the sub-clustered neural cells, colored by sample time point. (B) UMAP of the sub-clustered neural cells, colored by neural cell-type identities that were assigned based on expression of known larval and adult sea urchin neural patterning genes. Note that several clusters are labeled only as ‘differentiated neurons’ because they matched no known neural cell-type signature. (C) Clustered dot plot of the expression levels of 30 neural TFs in each of the He neural cell types. Clustering was performed using k-means clustering with k=10. (D) HCR micrographs in 56 hpf He larvae for hmx and lim1, two TFs that are expressed in neurons in He. The first column depicts expression in neurons in the larval ectoderm. The second column shows a more interior view of the larva, where these genes have expression in the adult rudiment. Scale bars: 50 µm.