The cellular retinoic acid-binding protein type I (CRABPI) is encoded by a single gene in mammals. We have characterized twocrabp1genes in zebra-fish, designatedcrabp1a and crabp1b. These twocrabp1 genes share the same gene structure as the mammalianCRABP1genes and encode proteins that show the highest amino acid sequence identity to mammalian CRAB-PIs. The zebrafishcrabp1aandcrabp1bwere assigned to linkage groups 25 and 7, respectively.