Transcriptome profile of the developing sponge. (A) Correlation of expression for 13,503 genes detected above the cutoff threshold across different stages of development (r, Pearson correlation coefficient). The x and y axes are log2 of read counts +1 normalized to the total number of mapped reads. (B) Expression profile for genes that are differentially expressed during development. Data for 4,677 genes with greater than four-fold change in expression in one stage compared to the other three stages is shown (p < 0.05, two-tailed t-test). Each row represents data for one gene. Pelagic stages include precompetent (PRE) and competent (COMP) larvae; benthic stages include postlarvae (POST) and adult (ADULT). (C) Gene ontology (GO) analysis for gene groups up- or downregulated by greater than four-fold between successive stages. Enrichment p-values for selected terms are shown. GO terms are grouped by stage transition (indicated by gray bars to the right) while colored bars indicate the direction of change (up or downregulation) at each transition.