MNNG treated Excherichia coli reveal new up or down regulated genes belonging to the Ada regulon

An oligonucleotide tiling array technology is utilized to measure the entire Escherichia coli transcriptome and its transcriptional changes after induction of the adaptive response by the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Keywords: Gene expression during the adaptive response in Escherichia coli Escherichia coli K-12 MG1655 single colony in five parallells was grown to mid-log phase and exposed to the ada-response inducer MNNG. Total RNA was extracted from induced and uninduced cells and cDNA was prepared, fragmented and labelled prior to hybridizing to arrays. The Escherichia coli genome was split in two; sequences encoding proteins, tRNAs or rRNAs with a known function on either strand, and sequences without such annotation. A selective tiling approach was used to ensure sufficient coverage of unnanotated genomic regions due to the limited number of array probes.