Supplementary tables used in this study.

<b>Table S1.</b> ImageStream raw data used in Fig. 1. <b>Table S2.</b> DESeq2 results of RLRb high versus RLRb low immunostaining shown in Fig. 1F. <b>Table S3.</b> GSEA results shown in Fig. 1G. <b>Table S4.</b> DESeq2 results of mCherry positive versus mCherry negative sorted cells. Used in Fig. 3 H-j. <b>Table S5.</b> GSEA results shown in Fig. 3J. <b>Table S6. </b>Single-cell RNA-seq quality metrics and metacell expression matrix. Sheet “QC_metrics” contains CellRanger run summary statistics for the two biological replicates (Nvec01 and Nvec02), including cell numbers, sequencing depth, mapping rates, and RNA capture metrics. Sheet “Metacell_UMIs” contains normalized UMI fractions for each gene across all metacells and was used to generate the metacell-level expression profiles shown in Fig. 5B.. <b>Table S7.</b> Differential expression analysis of poly(I:C) versus NaCl treated embryos using MAST on scRNAseq data. <b>Table S8.</b> Marker genes reported by Cole et al. (48) <b>Table S9.</b> Cell cluster markers identified in this study. Used in fig. S6. <b>Table S10.</b> MAST differential expression for cluster 1 and GSEA results. <b>Table S11.</b> WGCNA analysis for identifying gene modules (fig. S7). <b>Table S12.</b> ORA results for GS17 (brown) gene module. <b>Table S13.</b> ORA results for GS16 (lightcyan) gene module. <b>Table S14.</b> ORA results for GS14 (red) gene module. <b>Table S15.</b> ORA results for GS15 (purple) gene module. <b>Table S16.</b> Marker genes identified in sub-clusters 0-3. Used in Fig. 6. <b>Table S17.</b> ORA results for sub-cluster 0. <b>Table S18.</b> ORA results for sub-cluster 1. <b>Table S19.</b> ORA results for sub-cluster 2. <b>Table S20.</b> ORA results for sub-cluster 3. <b>Table S21.</b> Orthofinder output used for orthogroups identification in Fig. 7. <b>Table S22.</b> Shared single orthogroups and their gene expression used for correlation analysis in Fig. 7D. <b>Table S23.</b> Shared genes with adjusted p value &lt; 0.05 used for correlation analysis in Fig. 7E. <b>Table S24.</b> Genes that were shared between cluster in the non-injected control and the immune cluster in adult Nematostella identified by Cole et al. (48). <b>Table S25.</b> Dictionary for converting NVE gene models, NV2, and the gene models used in this study and their associated annotations.