title: Interspecific comparison of the unusually repetitive Drosophila locus mastermind.
abstract: The mastermind gene of Drosophila melanogaster encodes a novel, highly repetitive nuclear protein required for neural development. To identify functionally important regions we have initiated an interspecific comparison of the gene in Drosophila virilis. Mastermind transcription and genomic organization are similar in both species and sequence analysis reveals significant conservation in a major cluster of charged amino acids. In contrast, extensive variation is noted in homopolymer domains that immediately flank the acidic cluster. Distinct patterns of evolutionary change can be identified: the major difference between unique regions are occasional amino acid substitutions whereas the repetitive areas are characterized by numerous large in-frame insertions/deletions and a nearly threefold higher rate of amino acid replacement. Conservation of the acidic domain suggests that it has an important functional role whereas the hypervariable homopolymer regions appear to be under less selective constraints than adjacent unique areas.
authors.affiliation: Department of Biology, Emory University, Atlanta, GA 30322.
authors.forename: S J
authors.initials: SJ
authors.lastname: Newfeld
authors.forename: D A
authors.initials: DA
authors.lastname: Smoller
authors.forename: B
authors.initials: B
authors.lastname: Yedvobnick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002490:Central Nervous System / Q000196:embryology; D003001:Cloning, Molecular; D004247:DNA; D004330:Drosophila / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D016415:Sequence Alignment; D013045:Species Specificity
chemical_list: D009687:Nuclear Proteins; D004247:DNA