The best approach would be to isolate RNA for both tissues, prepare cDNAs,, and sequence the cDNAs to determine if there were differences between tissues. These results could be related to the genomic DNA sequences which indicate full sequence of the gene and the location of introns.
Cyclic AMP can bind to a protein called CRP (cyclic AMP receptor protein). That complex can then bind to a region near the lac promoter. Binding of the complex facilitates transcription of the operon (positive control of transcription).