Isolation and analysis of a new hopper hAT transposon from the Bactrocera dorsalis white eye strain

Authors: Handler, Alfred - Al

Submitted to: Genetica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2002
Publication Date: 2/7/2003
Citation: Handler, A.M. 2003. Isolation and analysis of a new hopper hAT transposon from the Bactrocera dorsalis white eye strain. Genetica. 118:18-24.

Interpretive Summary: The ability to achieve gene transfer in economically important insects is a major goal of our laboratory at the CMAVE. This will depend upon the identification and isolation of new transposable elements that may be developed into gene vectors. In this report we describe results from experiments that have isolated a new hopper element from the white eye mutant strain of the Oriental fruit fly, Bactrocera dorsalis. Unlike the original hopper isolated from the Kahuku strain of this species, the white eye hopper has a DNA and amino acid sequence consistent with a functional transposon. Comparisons with other related elements in the hobo, Ac, Tam3 transposon family also show that hopper is the most distantly related element among those that exist in insects. This is encouraging for the future use of hopper as a gene-transfer vecto system, and also provides information of the evolutiobnarry history of its transposon family.

Technical Abstract: A new hopper element belonging to the hAT transposon family was isolated from the white eye mutant strain of the Oriental fruit fly, Bactrocera dorsalis. Using the original hopper element sequence from the wild type Kahuku strain as a template, the new hopper was isolated by inverse and direct PCR. Nucleotide sequence analysis reveals a 3,131 by element with terminal and subterminal inverted repeat sequences, an 8-bp duplicated insertion site, and a conceptual translation yielding a single uninterrupted 650 amino acid open reading frame. Unlike the Kahuku element, the white eye hopper has structure consistent with functionality, indicating that hopper is not an artifactual element, as well as the possibility that it was more recently introduced into the species. The hopper element remains distantly related to other known hAT elements including those from insects, and it is most closely related to Activator-related elements discovered in the human genome. DNA hybridization studies indicate, however, that elements closely related to hopper exist in another bactrocerid species, the melonfly, B. cucurbitae.