title: The pugilistDominant Mutation of Drosophila melanogaster: A Simple-Sequence Repeat Disorder Reveals Localized Transport in the Eye.
abstract: The pugilist-Dominant mutation results from fusion of a portion of the gene encoding the tri-functional Methylene Tetrahydrofolate Dehydrogenase (E.C.1.5.1.5, E.C.3.5.4.9, E.C.6.3.4.3) to approximately one kb of a heterochromatic satellite repeat. Expression of this fusion gene results in an unusual ring pattern of pigmentation around the eye. We carried out experiments to determine the mechanism for this pattern. By using FLP-mediated DNA mobilization to place different pugD transgenes at pre-selected sites we found that variation in repeat length makes a strong contribution to variability of the pug phenotype. This variation is manifest primarily as differences in the thickness of the pigmented ring. We show that similar phenotypic variation can also be achieved by changing gene copy number. We found that the pugD pattern is not controlled by wingless, which is normally expressed in a similar ring pattern. Finally, we found that physical injury to a pugD eye can lead to pigment deposition in parts of the eye that would not have been pigmented in the absence of injury. Our results are consistent with a model in which a metabolite vital for pigment formation is imported from the periphery of the eye, and pugD limits the extent of its transport towards the center of the eye, thus revealing the existence of a hitherto unknown mechanism of localized transport in the eye.
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, Utah, United States of America.
authors.forename: Yikang S
authors.initials: YS
authors.lastname: Rong
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, Utah, United States of America.
authors.forename: Mary M
authors.initials: MM
authors.lastname: Golic
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, Utah, United States of America.
authors.forename: Kent G
authors.initials: KG
authors.lastname: Golic
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000378:metabolism; D001483:Base Sequence; D045584:Chromosome Positioning / Q000235:genetics; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004251:DNA Transposable Elements / Q000235:genetics; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D005123:Eye / Q000378:metabolism*; D018628:Gene Dosage; D005799:Genes, Dominant; D017344:Genes, Insect; D005822:Genetic Vectors / Q000378:metabolism; D007267:Injections; D026901:Membrane Transport Proteins / Q000378:metabolism*; D018895:Microsatellite Repeats / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D010858:Pigmentation; D021381:Protein Transport; D011621:Pteridines / Q000378:metabolism; D011679:Pupa / Q000378:metabolism; D019076:Transgenes; D051155:Wnt1 Protein / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D026901:Membrane Transport Proteins; D011621:Pteridines; D051155:Wnt1 Protein; C000609691:pug protein, Drosophila; C074622:wg protein, Drosophila; D004254:DNA Nucleotidyltransferases; C045119:FLP recombinase