title: Rescue from oculocutaneous albinism type 4 using medaka slc45a2 cDNA driven by its own promoter.
abstract: Patients and vertebrate mutants with oculocutaneous albinism type 4 (OCA4) have mutations in the solute carrier family 45 member 2 (slc45a2) gene. However, there is no empirical evidence for this gene-phenotype relationship. There is a unique OCA4 mutant in medaka (b) that exhibits albinism only in the skin, but the mechanism underlying this phenotype is also unknown. In this study, we rescued medaka OCA4 phenotypes, in both the eyes and the skin, by micro-injection of an slc45a2-containing genomic fragment or slc45a2 cDNA driven by its own 0.9-kb promoter. We also identified a spontaneous nucleotide change of 339 bp in the promoter as the b mutation. There are multiple transcription start sites in medaka slc45a2, as in its human ortholog, and only the shortest and eye-specific mRNA is transcribed with the b mutation. Interestingly, we further revealed a conserved pyrimidine (Py)-rich sequence of approximately 10 bp in the promoter by medaka-pufferfish comparative genomics and verified that it plays an indispensable role for expression of slc45a2 in the skin. Further studies of the 0.9-kb promoter identified in this study should provide insights into the cis/trans-regulatory mechanisms underlying the ocular and cutaneous expression of slc45a2.
authors.affiliation: Department of Integrated Biosciences, University of Tokyo, Chiba, Japan. shoji.fukamachi@uni-konstanz.de
authors.forename: Shoji
authors.initials: S
authors.lastname: Fukamachi
authors.forename: Masato
authors.initials: M
authors.lastname: Kinoshita
authors.forename: Taro
authors.initials: T
authors.lastname: Tsujimura
authors.forename: Atsuko
authors.initials: A
authors.lastname: Shimada
authors.forename: Shoji
authors.initials: S
authors.lastname: Oda
authors.forename: Akihiro
authors.initials: A
authors.lastname: Shima
authors.forename: Axel
authors.initials: A
authors.lastname: Meyer
authors.forename: Shoji
authors.initials: S
authors.lastname: Kawamura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mitani
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D000417:Albinism / Q000235:genetics* / Q000662:veterinary; D000818:Animals; D022202:Chromosomes, Artificial, Bacterial; D018076:DNA, Complementary / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D005136:Eye Proteins / Q000235:genetics; D005393:Fish Diseases / Q000235:genetics; D005786:Gene Expression Regulation; D026901:Membrane Transport Proteins / Q000235:genetics*; D009154:Mutation; D009990:Oryzias / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D020121:5' Untranslated Regions; D018076:DNA, Complementary; D005136:Eye Proteins; D026901:Membrane Transport Proteins