Fig. 3.

A novel anthozoan-specific CRY class is characterized by tandemly duplicated PHR domains. (A) A majority rule extended consensus tree topology generated with IQTree constructed from the combined bootstrap trees showing that PLs (CPD-II, PLs, and (6-4) PLs) and CRY-DASHs are common amongst all Cnidaria. Other CRYs including CRY-II occur only in Anthozoa but are entirely absent from Medusozoa. The present phylogeny is supported by highly conserved and specific exon–intron patterns (supplementary fig. 5, Supplementary Material online) suggesting that CRY-IIs and (6-4) PLs share a common origin. A well supported but previously unidentified, anthozoan-specific CRY family resolves at the base of animal CRY-IIs and (6-4) PLs which we name Anthozoan-specific CRYs (AnthoCRYs). Support values are SH-aLRT bootstrap percentages/UFBoots bootstrap percentages/MrBayes Bayesian posterior probabilities. A full tree can be accessed through supplementary file 5, Supplementary Material online. (B) CRYs (except CRY-DASH) are absent in Medusozoa, whereas the Anthozoa possess a novel class of cryptochromes (AnthoCRYs), which contain unique tandem duplications including up to six copies of the PHR region comprising the N-terminal DNA-binding PL domain (also called alpha/beta domain, red) and the chromophore-binding FAD domain (gray). (C) A comparison between cDNA- and genomic DNA-derived exon-spanning amplicon sequencing confirms this PHR region duplication in Aiptasia AnthoCRY.1 (XP_020902079).