Concerted evolution within the Drosophila dumpy gene.
We have determined by reverse Southern analysis and direct sequence comparisons that most of the dumpy gene has evolved in the dipteran and other insect orders by purifying selection acting on amino acid replacements. One region, however, is evolving rapidly due to unequal crossing over and/or gene conversion. This region, called "PIGSFEAST," or PF, encodes in D. melanogaster 30-47 repeats of 102 amino acids rich in serines, threonines, and prolines. We show that the processes of concerted evolution have been operating on all species of Drosophila examined to date, but that an adjacent region has expanded in Anopheles gambiae, Aedes aegypti, and Tribolium castaneum, while the PF repeats are reduced in size and number. In addition, processes of concerted evolution have radically altered the codon usage patterns in D. melanogaster, D. pseudoobscura, and D. virilis compared with the rest of the dumpy gene. We show also that the dumpy gene is expressed on the inner surface of the micropyle of the mature oocyte and propose that, as in the abalone system, concerted evolution may be involved in adaptive changes affecting Dumpy's possible role in sperm-egg recognition.
Carmon
Amber
A
Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
Wilkin
Marian
M
Hassan
Jana
J
Baron
Martin
M
MacIntyre
Ross
R
D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000235:genetics; D001483:Base Sequence; D015139:Blotting, Southern; D003062:Codon / Q000235:genetics; D017124:Conserved Sequence; D003434:Crossing Over, Genetic; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000235:genetics*; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid; D012641:Selection, Genetic; D013045:Species Specificity
D003062:Codon; C411950:DPY protein, Drosophila; D029721:Drosophila Proteins; D016326:Extracellular Matrix Proteins; D012333:RNA, Messenger