Comparison of RNAi Sequences in Insect-Resistant Plants to Expressed Sequences of a Beneficial Lady Beetle: A Closer Look at Off-Target Considerations

Sequences obtained from transcriptomes of the lady beetle Coleomegilla maculata were compared to those designed for incorporation into crops. Searches of the transcriptomes identified sequences as the most likely to be closely similar to the sequences described in RNAi plant incorporated products. Some proposed prime RNAi pest management targets were also used to identify predicted orthologs from C. maculata. The lady beetle sequences were aligned with sequences from corn rootworms and Colorado potato beetles and, as appropriate in the case of targets, regions of similarity were compared with the genetic model organism for beetles, Tribolium castaneum. Some high levels of nucleotide identity were identified, particularly with an actin-derived sequence from Colorado potato beetle. This actin-derived sequence shared identical sequences with the lady beetle and a parasitic wasp.