Map of major histocompatibility genes and their paralogues in zebrafish (not to scale). Only chromosomes and two unmapped contigs (NA17761 and NA17767) that harbour MHC-related genes are shown. Orthologues or paralogues of human MHC class I region genes are shown in red, of class II region genes in blue, and class III region genes in green. Genes with the suffix "L" for like are either gene fragments and/or highly similar to their human counterparts. Genes that have more than one copy in the genome are shown by a greater than (>) symbol. Similarities and differences between the whole-genome assembly and mapping information present in the ZFIN database are shown by plus (+) and minus (-) signs, respectively. The core MHC has been compiled from five genomic clones spanning this region [EMBL:AL672216, EMBL:AL672151, EMBL:AL672164, EMBL:AL672176].