title: The ABCs of eye color in Tribolium castaneum: orthologs of the Drosophila white, scarlet, and brown Genes.
abstract: In Drosophila melanogaster, each of the three paralogous ABC transporters, White, Scarlet and Brown, is required for normal pigmentation of the compound eye. We have cloned the three orthologous genes from the beetle Tribolium castaneum. Conceptual translations of Tribolium white (Tcw), scarlet (Tcst), and brown (Tcbw) are 51, 48, and 32% identical to their respective Drosophila counterparts. We have identified loss-of-eye-pigment strains that bear mutations in Tcw and Tcst: the Tcw gene in the ivory (i) strain carries a single-base transversion, which leads to an E → D amino-acid substitution in the highly conserved Walker B motif, while the Tcst gene in the pearl (p) strain has a deletion resulting in incorporation of a premature stop codon. In light of these findings, the mutant strains i and p are herein renamed white(ivory) (w(i)) and scarlet(pearl) (st(p)), respectively. In addition, RNA inhibition of Tcw and Tcst recapitulates the mutant phenotypes, confirming the roles of these genes in normal eye pigmentation, while RNA interference of Tcbw provides further evidence that it has no role in eye pigmentation in Tribolium. We also consider the evolutionary implications of our findings.
authors.affiliation: Department of Entomology, North Carolina State University, Raleigh, North Carolina 27695.
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Grubbs
authors.affiliation: U.S. Department of Agriculture-Agricultural Research Service-Center for Grain and Animal Health Research, Manhattan, Kansas 66502.
authors.forename: Sue
authors.initials: S
authors.lastname: Haas
authors.affiliation: U.S. Department of Agriculture-Agricultural Research Service-Center for Grain and Animal Health Research, Manhattan, Kansas 66502.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Beeman
authors.affiliation: Department of Entomology, North Carolina State University, Raleigh, North Carolina 27695 marce_lorenzen@ncsu.edu.
authors.forename: Marcé D
authors.initials: MD
authors.lastname: Lorenzen
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D029721:Drosophila Proteins / Q000235:genetics; D019143:Evolution, Molecular; D005127:Eye Color / Q000235:genetics*; D005136:Eye Proteins / Q000235:genetics; D017344:Genes, Insect; D008969:Molecular Sequence Data; D009154:Mutation; D014231:Tribolium / Q000235:genetics*
chemical_list: D018528:ATP-Binding Cassette Transporters; D029721:Drosophila Proteins; D005136:Eye Proteins; C059253:bw protein, Drosophila; C090596:st protein, Drosophila; C059254:w protein, Drosophila
keywords: ABC transporters; evolution of development; eye pigmentation