Regulatory potential of nonautonomous mariner elements and subfamily crosstalk.
Two naturally occurring nonautonomous mariner elements were tested in vivo for their ability to down-regulate excision of a target element in the presence of functional mariner transposase. The tested elements were the peach element isolated from Drosophila mauritiana, which encodes a transposase that differs from the autonomous element Mos1 in four amino acid replacements, and the DTBZ1 element isolated from D. teissieri, which encodes a truncated protein consisting of the first 132 residues at the amino end of the normally 345-residue transposase. We provide evidence that the protein from the peach element does interact to down-regulate wildtype transposase, indicating that at least some nonautonomous elements in natural populations that retain their open reading frame may play a regulatory role. In contrast, our tests reveal at most a weak interaction between transposase from the autonomous Mos1 element and the truncated protein from DTBZ1, and none between Mos1 transposase and that from the distantly related mariner-like element Himar1 identified in the horn fly Haematobia irritans. Hence, the extent of regulatory crosstalk between mariner-like elements may be limited to closely related ones. The evolutionary implications of these results are discussed.
De Aguiar
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USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL 32604, USA.
Hartl
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D000818:Animals; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins / Q000235:genetics*; D004330:Drosophila / Q000235:genetics*; D019143:Evolution, Molecular; D012045:Regulatory Sequences, Nucleic Acid; D019895:Transposases / Q000235:genetics
D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; C111652:mariner transposases; D019895:Transposases