Retinol Metabolism in the Mollusk Osilinus lineatus Indicates an Ancient Origin for Retinyl Ester Storage Capacity
Figure 7
Distribution of retinyl ester storage capacity and canonical/molluskan retinoid pathways
. (A) Phylogenetic distribution of the confirmed presence of retinyl ester storage capacity in different bilaterian groups. The inference of RE in Lophotrocozoa is derived from Osilinus lineatus. (B) Canonical metabolic pathways from retinyl esters (REs) to retinoic acid (RA). Black arrows indicate the metabolic transformations that are known to occur in amniotes. Green arrows indicate the steps that are functional in the mollusk Osilinus lineatus. The red arrow indicates the metabolic transformations that remain to be demonstrated in O. lineatus. (ROL) retinol; (RAL) retinaldehyde.