BMC Genomics. 2012 Feb 2;13:55. doi:10.1186/1471-2164-13-55

Yadetie F, Butcher S, Førde HE, Campsteijn C, Bouquet JM, Karlsen OA, Denoeud F, Metpally R, Thompson EM, Manak JR, Goksøyr A, Chourrout D.

Conservation and divergence of chemical defense system in the tunicate Oikopleura dioica revealed by genome wide response to two xenobiotics.

“Oikopleura appears to have the smallest CYP complement of sequenced animal genomes and has no detectable CYP1 family genes. AhR, which is the transcriptional regulator of CYP1 family genes in vertebrates, is also undetectable in Oikopleura. Thus, the AhR signaling pathway may not exist in Oikopleura. Components of the Nrf2 signaling pathway appear to be conserved in Oikopleura.”