Fig. 1

Summary of the identified neuropeptide precursors from U. unicinctus larval and adult transcriptomes. a pNPs are classified based on their phylogenetic distribution into eumetazoan, bilaterian, protostome (prot.), lophotrochozoan, annelid (ann.) and Urechis-specific. Previously established metazoan neuropeptide families are indicated in red [28]. b Hierarchical clustering of the neuropeptide precursor genes in U. unicinctus larval transcriptomes [29]. LT, late-trochophore (25 dpf, pelagic larva); ES, early- segmented larva (32 dpf, pelagic larva); SL, segmented larva (35 dpf, competent larva); WL, worm-shaped larva (42 dpf, benthic larva). Colors represent the gene expression levels from green (low), black (middle) to red (high)