Identification of two novel P450 genes and their responses to deltamethrin in the cabbage moth, Mamestra brassicae Linnaeus

- Two novel cytochrome P450 genes named CYP4M51 and CYP6AB56 were identified from the cabbage moth, Mamestra brassicae Linnaeus.
- They had differentially expressed patterns at different larval developmental stages and in different tissues.
- The mRNA expression levels of these two cytochrome P450 genes could be up-regulated by deltamethrin.
- RNAi reduced mRNA levels and increased larvae mortalities.

Cytochrome P450 monooxygenases, found in virtually all living organisms, play an important role in the metabolism of xenobiotics such as drugs, pesticides, and plant toxins. In this study, we identified two novel cytochrome P450 genes from the cabbage moth, Mamestra brassicae Linnaeus. They were named CYP4M51 and CYP6AB56 (GenBank Accession Nos.: KX008607 and JQ901385, respectively) by the P450 Nomenclature Committee. Real-time quantitative reverse transcription revealed that CYP4M51 and CYP6AB56 were highly expressed in the fat bodies and were differentially expressed at different larval developmental stages. Expression levels of these two cytochrome P450 genes were up-regulated by deltamethrin. Analyses of their detoxification roles using RNA interference followed by a deltamethrin bioassay showed that larvae mortalities increased by 11.4% and 21.6%, respectively, after CYP4M51 and CYP6AB56 were partially silenced. These results suggest that inhibition of the novel cytochrome P450 genes CYP4M51 and CYP6AB56 could be used to increase the efficacy of cabbage moth control by deltamethrin.

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