The hAT-family transposable element, hopper, from Bactrocera dorsalis is a vector for insect germline transformation

Authors: Handler, Alfred - Al; SCHETELIG, MARC - Justus-Liebig University

Submitted to: BioMed Central (BMC) Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2020
Publication Date: 12/18/2020
Publication URL: https://handle.nal.usda.gov/10113/7207910
Citation: Handler, A.M., Schetelig, M. 2020. The hAT-family transposable element, hopper, from Bactrocera dorsalis is a functional vector for insect germline transformation. BioMed Central (BMC) Genetics. 21, Article 137. https://doi.org/10.1186/s12863-020-00942-3.
DOI: https://doi.org/10.1186/s12863-020-00942-3

Interpretive Summary: The ability to achieve gene transfer in economically important insects is a major goal of USDA. The ability to genetically manipulate agriculturally important fruit fly pest species and improve components to sterile insect technique (SIT) control programs presents the possibility to create new strains that eliminate females during rearing and sterilize surviving males for more efficient and cost-effective SIT programs. Scientists at the USDA, ARS, Center for Medical Agricultural and Veterinary Entomology, Gainesville, Florida, have tested the functionality of a new transposable element named “hopper”, isolated from the Oriental fruit fly, as a transformation vector in Drosophila and the Caribbean fruit fly. Efficient transformation was achieved with hopper vectors in both species. The hopper transposon vector provides a new resource for genetic modifications in the these and potentially other agricultural pest insects.

Technical Abstract: Background: The hopper hAT-family transposable element isolated from the Oriental fruit fly, Bactrocera dorsalis, is distantly related to both the Drosophila hobo element and the Activator element from maize. The original 3,120 bp hopperBd-Kah element isolated from the Kahuku wild-type strain was highly degenerate and appeared to have a mutated transposase and inverted terminal sequences, while a second 3,131 bp element isolated from a white eye mutant strain had an intact transposase reading frame and terminal sequences consistent with function. Results: The putative hopperBd-we functional element was used to create a binary vector and helper transformation system by linking the transposase reading frame to a D. melanogaster hsp70 promoter for a heat-inducible transposase helper plasmid, and creating vectors marked with the D. melanogaster mini-white+ and polyubiquitin-regulated DsRed markers. Conclusions: Both vectors were successfully used to transform D. melanogaster, and the DsRed vector was also used to transform the Caribbean fruit fly, Anastrepha suspensa, indicating a wide range of hopper function in dipteran species and, potentially, non-dipteran species. This vector provides a new tool for insect genetic modification for both functional genomic analysis and the control of insect populations.