Cloning and characterization ofmariner-like elements in the soybean aphid,Aphis glycinesMatsumura

Abstract

AbstractSoybean aphid,Aphis glycinesMatsumura (Hemiptera: Aphididae), is currently the most important insect pest of soybean (Glycine max(L.) Merr.) in the United States and causes significant economic damage worldwide, but little is known about the aphid at the molecular level.Mariner-like transposable elements (MLEs) are ubiquitous within the genomes of arthropods and various other invertebrates. In this study, we report the cloning of MLEs from the soybean aphid genome using degenerate PCR primers designed to amplify conserved regions ofmarinertransposases. Two of the ten sequenced clones (designated asAgmar1andAgmar2) contained partial but continuous open reading frames, which shared high levels of homology at the protein level with othermarinertransposases from insects and other taxa. Phylogenetic analysis revealedAgmar1to group within the irritans subfamily of MLEs andAgmar2within the mellifera subfamily. Southern blot analysis and quantitative PCR analysis indicated a low copy number forAgmar1-like elements within the soybean aphid genome. These results suggest the presence of at least two different putativemariner-like transposases encoded by the soybean aphid genome. BothAgmar1andAgmar2could play influential roles in the architecture of the soybean aphid genome. Transposable elements are also thought to potentially mediate resistance in insects through changes in gene amplification and mutations in coding sequences. Finally,Agmar1andAgmar2may represent useful genetic tools and provide insights onA. glycinesadaptation.