Germline transformation of Drosophila melanogaster with the piggyBac transposon vector

Germline transformation of Drosophila melanogaster was attempted with the p iggyBac gene-transfer system from the cabbage looper moth, Trichoplusia ni. Using a self-regulated transposase helper and a white marked vector, a tra nsformation frequency of 1-3% per fertile GO was obtained, similar to that previously achieved in the medfly. Use of an hsp70-regulated helper increas ed this frequency more than eight-fold. Transformation with a vector marked with white and green fluorescent protein (GFP) under polyubiquitin-nuclear localizing sequence regulation yielded seventy G1 transformants which all expressed GFP, but only twenty-seven of these expressed eye pigmentation th at would have allowed their selection based on white(+) expression, PiggyBa c transformation in two distantly related dipteran species and efficient ex pression of the gfp marker supports the potential use of this system in oth er dipterans, and perhaps insects in general.