Reduced abundance of the CYP6CY3-targeting let-7 and miR-100 miRNAs accounts for host adaptation of Myzus persicae nicotianae. (August 2016)

• Record Type: Journal Article
• Authors: Peng, Tianfei; Pan, Yiou; Gao, Xiwu; Xi, Jinghui; Zhang, Lei; Ma, Kangsheng; Wu, Yongqiang; Zhang, Juhong; Shang, Qingli
• Is Part Of: Insect biochemistry and molecular biology. Volume 75(2016:Aug.)
• Page Start: 89
• Page End: 97
• Publication Date: 2016-08
• Subjects: Cytochrome P450 -- Gene regulation -- miRNA -- Host adaptation; Insect biochemistry -- Periodicals; Insects -- Physiology -- Periodicals; Insects -- Molecular aspects -- Periodicals; Biochemistry -- Periodicals; Insectes -- Biochimie -- Périodiques; Insectes -- Composition -- Périodiques; Insectes -- Physiologie -- Périodiques; Insectes -- Aspect moléculaire -- Périodiques; Biochimie -- Périodiques; Biochemistry; Insect biochemistry; Insects -- Molecular aspects; Insects -- Physiology; Periodicals; 572.8157
• DOI: 10.1016/j.ibmb.2016.06.002
• Languages: English
• ISSNs: 0965-1748

Abstract

Abstract: Nicotine is one of the most abundant and toxic secondary plant metabolites in nature and is defined by high toxicity to plant-feeding insects. Studies suggest that increased expression of cytochrome P450 ( CYP6CY3 ) and the homologous CYP6CY4 genes in Myzus persicae nicotianae is correlated with tolerance to nicotine. Indeed, through expression analyses of the CYP6CY3 and CYP6CY4 genes of different M. persicae subspecies, we determined that the mRNA levels of these two genes were much higher in M . persicae nicotianae than in M. persicae sensu stricto. We hypothesized that the expression of these two genes is subject to post-transcriptional regulation. To investigate the underlying mechanism, the miRNA profile of M . persicae nicotianae was sequenced, and twenty-two miRNAs were predicted to target CYP6CY3 . Validation of these miRNAs identified two miRNAs, let-7 and miR-100, whose abundance was highly inversely correlated with the abundance of the CYP6CY3 gene. This result implies that the let-7 and miR-100 miRNAs play a major role in the post-transcriptional regulation of the CYP6CY3 gene. Modulation of the abundance of let-7 and miR-100 through the addition of inhibitors/mimics of let-7 or miR-100 to artificial diet significantly altered the tolerance of M . persicae nicotianae to nicotine, further confirming the regulatory role of these two miRNAs. Interestingly, after decreasing the transcript levels of CYP6CY3 by modulating regulatory miRNAs, the transcript levels of the homologous isozyme CYP6CY4 were significantly elevated, suggesting a compensatory mechanism between the CYP6CY3 gene and its homologous CYP6CY4 gene. Our findings provide insight into the molecular drivers of insect host shifts and reveal an important source of genetic variation for adaptive evolution in insect species. Graphical abstract: Highlights: Abundances of let-7 and miR-100 are less in M. persicae nicotianae compared to M. persicae s.s . Modulation of let-7 and miR-100 impacts on CYP6CY3 expression and nicotine susceptibility. let-7 was more effective than miR-100 to negatively regulate CYP6CY3 . let-7 and miR-100 have the opposite effect on the transcript levels of CYP6CY4 compared with CYP6CY3 .