Enhanced expression of DNA methyltransferase 1-associated protein1 gene thermotolerance in a high-temperature acclimated predatory mite Neoseiulus barkeri

Predatory mites, that are important natural enemies of small sap-feeding pests, often tolerate various fluctuating environmental stresses. DNA methylation has been demonstrated to play critical roles in regulating transcriptional changes in response to environmental stress. To investigate whether the thermal tolerance of a high temperature acclimated strain (HTAS) of the predatory mite Neoseiulus barkeri Hughes is associated with DNA methylation mechanisms, we cloned and sequenced its DNA methyltransferase 1-associated protein1 (DMAP1). Quantitative real-time PCR analysis of transcript abundances revealed that NbDMAP1 was expressed ubiquitously at all developmental stages of N. barkeri and was also significantly upregulated after exposure to 38 °C and 42 °C. The expression of NbDMAP1 in the HTAS N. barkeri showed a significant increase compared to the conventional strain N. barkeri after exposure to 42 °C. Feeding on double-stranded RNA specific for NbDMAP1, however, significantly decreased the thermal tolerance of HTAS and also increased its mortality rate. This study suggests DNA methylation played a potential role in thermal tolerance of N. barkeri, which is an important mechanism for its successful colonization under thermal environments and commercialization for pest control.