Trans-complementation of an endonuclease-defective tagged I element as a tool for the study of retrotransposition in Drosophila melanogaster.
I factors are non-LTR retrotransposons of Drosophila melanogaster that transpose at high frequency in the germline of females resulting from appropriate crosses, allowing in vivo studies of the retrotransposition process. Reverse transcription of a full-length RNA intermediate is thought to occur at the site of integration, using a 3' hydroxyl group generated by endonucleolytic cleavage of the genomic DNA to prime synthesis of the first cDNA strand. This target-primed reverse transcription (TPRT) process is mediated by endonuclease and reverse transcriptase activities encoded by the element. We have designed a molecularly tagged, endonuclease-defective I element that can be mobilised with high efficiency by constructs that express the product of the I factor ORF2 in trans. This indicates that the endonuclease activity required for retrotransposition of the I factor can be provided in trans. Using this system, we show that the endonuclease domain of the R1Bm retrotransposon from Bombyx mori cannot functionally replace that of the I factor.
Robin
S
S
Institut de Génétique Humaine, CNRS, 141 Rue de la Cardonille, 34396 Montpellier Cedex 5, France.
Chambeyron
S
S
Brun
C
C
Bucheton
A
A
Busseau
I
I
D000818:Animals; D030801:Animals, Genetically Modified; D003433:Crosses, Genetic; D004331:Drosophila melanogaster / Q000235:genetics*; D004720:Endonucleases / Q000378:metabolism; D005260:Female; D005816:Genetic Complementation Test; D008297:Male; D018626:Retroelements; D017422:Sequence Analysis, DNA
D018626:Retroelements; D004720:Endonucleases