3.2. Comparative gene copy number and transcript levels of the
transformed carboxylesterase genes in transgenic Drosophila strains
The wild-type, G/A151D and W271L mutant CpEST and AgEST
were subjected to germline transformation to the third chromosome
of D. melanogaster. The DNA and RNA levels of the transferred
carboxylesterase genes in these transgenic lines were determined
by real-time qPCR. At the DNA level, the inserted-gene copy numbers
of the wild type and the two mutants were similar in CpEST (Fig. 3A)
and AgEST (Fig. 3B) transgenic lines. At carboxylesterase transcript
levels, no significant difference was observed in the
carboxylesterase expression induced by tub-Gal4 of wild-type and
mutant transgenic lines (Fig. 3C and D, P > 0.05 in one-way ANOVA).
This uniformity in the gene copy and transcript levels for the wildtype
and the corresponding mutant transgenic lines made the
comparison of carboxylesterase activity and insecticide resistance
level among these transgenic strains rational. No transcripts (leaky
expression) of the transferred carboxylesterase genes were detected
from UAS lines before crossing to tub-Gal4.