Using DNA Sequencing to Detect and Verify Genetically Modified Maize (Zea mays L.) in Iraq

Abstract

Polymerase chain reaction (PCR) was used to detect genetically modified maize. The results revealed that 10 out of 72 maize DNA samples were genetically modified. Verification of PCR ampliconse indicated that all GM maize were of MON810 type engineered with cryIAb gene under the control of the cauliflower mosaic virus P35S promoter and NOS terminator. Direct DNA sequencing for three out of the ten detected GM maize confirm the presence of P35S promoter and NOS terminator. Also, the constructed alignment of both genetic elements in comparison with their respective sequence in the NCBI database, indicated complete identity level for P35S, whereas nucleotide mismatches was detected in two sites of NOS118 terminator both on the forward strand. Meanwhile one site was corrected by the reverse strand, the other site may be resulted from Tag polymerase mismatches. These results approved the highly conservativeness of both detected elements and the completely absence of single nucleotide mutations. Results revealed clearly that nonauthorized GM maize was entered the national agriculture sector without authorities permission, which maximize risks of spreading GM maize all around the country and need to act immediately by setting strict legislation and monitoring system.