No abstract

RF microporation enhances the topical delivery of active ingredients with high molecular weight or of small hydrophilic or lipophilic molecules. Thus, this technology can effectively improve photo-induced hyperpigmentation and wrinkle formation by enhancing topical delivery of active agents.

BACKGROUND: Red flour beetle, Tribolium castaneum (T. castaneum), is a major agricultural pest that causes significant damage to stored grains and products. Although hormone receptor 96 (HR96) is known to be the single ortholog corresponding to mammalian constitutive androstane receptor and pregnane X receptor, the structural features of Tribolium HR96 (TcHR96) and its role in insecticide-mediated transcription control of cytochrome P450 enzyme genes in T. castaneum have not been elucidated yet.RESULTS: We cloned full-length complementary DNA encoding TcHR96 and revealed the role of TcHR96 in transcriptional control of cytochrome P450 enzyme genes. Interestingly, genome-wide transcriptome analysis of HR96-deficient beetles using RNA sequencing showed a positive correlation between TcHR96 and gene transcription of metabolizing enzymes involved in phase I detoxification processes. Moreover, TcHR96 overexpression significantly increased the promoter activity of genes encoding phase I P450 enzymes such as CYP4Q4, CYP4G7, CYP4BR3, and CYP345A1. Chromatin immunoprecipitation analysis showed that TcHR96 could directly bind to the promoter of gene encoding CYP345A1, an enzyme for metabolizing insecticides in T. castaneum. Furthermore, imidacloprid, a neonicotinoid insecticide, significantly increased gene expression of phase I P450 enzymes in old larvae of T. castaneum, which were reversed by TcHR96 knockdown. Finally, TcHR96 knockdown significantly decreased the resistance of old larvae to imidacloprid concomitant with reduction of imidacloprid-mediated phase I P450 enzyme gene expression.CONCLUSION: TcHR96 plays a major role in transcriptional control of P450 enzyme for imidacloprid detoxification. Controlling TcHR96 might facilitate the regulation of insecticide tolerance in T. castaneum, thus providing a promising new strategy to manage pest beetle populations.

No abstract

BACKGROUND Chitin, a major component of insect cuticles, plays a critical role in insect molting and morphogenesis. Thus, coordination of chitin remodeling during insect development requires tight transcriptional control of the chitin metabolism genes involved in chitin synthesis, assembly and degradation. However, the molecular mechanism underlying transcriptional coordination of chitin metabolism genes during beetle development is not yet completely understood. RESULTS We cloned the full‐length cDNA encoding hormone receptor 3 (TcHR3) from Tribolium castaneum and showed a critical role of TcHR3 in modulating chitin metabolism gene expression during molting. Genome‐wide transcriptome analysis of HR3‐deficient old larvae using RNA sequencing analysis revealed a positive correlation between TcHR3 and transcription of chitin metabolism genes involved in chitin synthesis and degradation. In addition, HR3 overexpression significantly induced the gene promoter activity of N‐acetylglucosaminidase 1 (NAG1) involved in chitin degradation and UDP‐N‐acetylglucosamine pyrophosphorylase 1 (UAP1) involved in chitin synthesis. Chromatin immunoprecipitation analysis revealed that HR3 could directly bind to HR3‐response element of NAG1 and UAP1 promoters. Finally, HR3‐deficient late instar larvae and prepupae exhibited defects in larval–larval and larval–pupal molting, respectively, leading to eventual larval death because developing larvae were trapped inside the old cuticle as a result of abnormal chitin metabolism. CONCLUSION TcHR3 is a transcriptional regulator of chitin metabolic genes for molting of T. castaneum. Controlling the molting system by TcHR3 might be a new management strategy for selective control of red flour beetle infestation. © 2022 Society of Chemical Industry.