A region in the middle of the first coding bnl exon has been replaced by sequence that encodes a lexA::p65 driver. A T2A self-cleaving peptide is present upstream of the driver sequence and a stop codon is present downstream of the driver sequence, to ensure that the driver is translated independently and not as part of a fusion protein with bnl. This results in the expression of a lexA::p65 driver under the control of the endogenous bnl regulatory sequences, including 5' and 3' UTR sequence, while the presence of the stop codon is expected to disrupt bnl function.
Ecol\lexAbnl-lexA drives expression in a pattern consistent with that of endogenous bnl at embryonic and larval stages.