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Akirin is a nuclear protein that controls development in vertebrates and invertebrates. The function of Akirin has not been assessed in any Coleopteran insects. We found that high levels of akirin transcripts in Henosepilachna vigintioctopunctata, a serious Coleopteran potato defoliator (hereafter Hvakirin), were present at prepupal, pupal and adult stages, especially in larval foregut and fat body. RNA interference (RNAi) targeting Hvakirin impaired larval development. The Hvakirin RNAi larvae arrested development at the final larval instar stage. They remained as stunted larvae, gradually blackened and finally died. Moreover, the remodelling of gut and fat body was inhibited in the Hvakirin depleted larvae. Two layers of cuticles, old and newly formed, were noted in the dsegfp‐injected animals. In contrast, only a layer of cuticle was found in the dsakirin‐injected beetles, indicating the arrest of larval development. Furthermore, the expression of three transforming growth factor‐β cascade genes (Hvsmox, Hvmyo and Hvbabo), a 20‐hydroxyecdysone (20E) receptor gene (HvEcR) and six 20E response genes (HvHR3, HvHR4, HvE75, HvBrC, HvE93 and Hvftz‐f1) was significantly repressed, consistent with decreased 20E signalling. Conversely, the transcription of a juvenile hormone (JH) biosynthesis gene (Hvjhamt), a JH receptor gene (HvMet) and two JH response genes (HvKr‐h1 and HvHairy) was greatly enhanced. Our findings suggest a critical role of Akirin in larval development in H. vigintioctopunctata. [ABSTRACT FROM AUTHOR]

Henosepilachna vigintioctomaculata is distributed in several Asian countries. The larvae and adults often cause substantial economic losses to Solanaceae crops such as potato, tomato, eggplant, and Chinese boxthorn. Even though a chromosome-level genome has been documented, the expression profiles of genes involved in development are not determined. In this study, we constructed embryonic, larval, pupal, and adult transcriptomes, generated a comprehensive RNA-sequencing dataset including ~52 Gb of clean data, and identified 602,773,686 cleaned reads and 33,269 unigenes. A total of 18,192 unigenes were successfully annotated against NCBI nonredundant protein sequences, Swissprot, Eukaryotic Orthologous Groups, Gene Ontology (GO), or Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. There were 3580, 2040, 5160, 2496, 3008, and 3895 differentially expressed genes (DEGs) between adult/egg, egg/larval, larval/pupal, adult/pupal, egg/pupal, and adult/larval samples, respectively. GO and KEGG analyses of the DEGs highlighted several critical pathways associated with specific developing stages. This is the first comprehensive transcriptomic dataset encompassing all developmental stages in H. vigintioctomaculata. Our data may facilitate the exploitation of gene targets for pest control and can serve as a valuable gene resource for future molecular investigations. [ABSTRACT FROM AUTHOR]

The C(sp3)–N bond is ubiquitous in natural products, pharmaceuticals, biologically active molecules and functional materials. Consequently, the development of practical and efficient methods for C(sp3)–N bond formation has attracted more and more attention. Compared to the conventional ionic pathway-based thermal methods, photochemical processes that proceed through radical mechanisms by merging photoredox and transition-metal catalyses have emerged as powerful and alternative tools for C(sp3)–N bond formation. In this review, recent advances in the burgeoning field of C(sp3)–N bond formation via metallaphotoredox catalysis have been highlighted. The contents of this review are categorized according to the transition metals used (copper, nickel, cobalt, palladium, and iron) together with photocatalysis. Emphasis is placed on methodology achievements and mechanistic insight, aiming to inspire chemists to invent more efficient radical-involved C(sp3)–N bond-forming reactions. [ABSTRACT FROM AUTHOR]

The Enterobacter cancerogenus strain EcHa1 was isolated from the dead larvae of Helicoverpa armigera, and has the potential for biocontrol of some Lepidoptera insects. In order to screen insecticidal-related genes by qRT-PCR, stable endogenous reference genes used for normalizing qRT-PCR data were selected and evaluated from 13 housekeeping genes (HKGs). The expression levels of the HKGs were determined using qRT-PCR under different experimental conditions, including two culture temperatures and three bacterial OD values. Five stability analysis methods (Ct, BestKeeper, NormFinder, geNorm, and RefFinder) were used to comprehensively rank the candidate genes. The results showed that the optimal reference genes varied under different experimental conditions. The combination of gyrA and gyrB was recommended as the best reference gene combination at 28 °C, while gyrA and rpoB was the best combination at 37 °C. When the OD values were 0.5, 1.0 and 2.0, the recommended reference gene combinations were ftsZ and gyrA, rpoB and gyrB, and gyrA and pyk, respectively. The most suitable reference genes were gyrA and gyrB under all experimental conditions. Using gyrA and gyrB as the reference genes for qRT-PCR, EcHa1 was found to invade all tissues of the H. armigera larvae, and expressed a candidate pathogenic factor Hcp at high levels in gut, Malpighian tubules, and epidermis tissues. This study not only establishes an accurate and reliable normalization for qRT-PCR in entomopathogenic bacteria but also lays a solid foundation for further study of functional genes in E. cancerogenus. [ABSTRACT FROM AUTHOR]

During choriogenesis in insects, chorion (eggshell) is formed by surrounding follicular epithelial cells in ovarioles. However, the regulatory endocrine factor(s) activating choriogenesis and the effect of chemical components on eggshell deserve further exploration. In two representative coleopterans, a coccinellid Henosepilachna vigintioctopunctata and a chrysomelid Leptinotarsa decemlineata, genes encoding the 20-hydroxyecdysone (20E) receptor heterodimer, ecdysone receptor (EcR) and ultraspiracle (USP), and two chitin biosynthesis enzymes UDP-N-acetylglucosamine pyrophosphorylase (UAP) and chitin synthase (ChS1), were highly expressed in ovaries of the young females. RNA interference (RNAi)-aided knockdown of either HvEcR or Hvusp in H. vigintioctopunctata inhibited oviposition, suppressed the expression of HvChS1, and lessened the positive signal of Calcofluor staining on the chorions, which suggests the reduction of a chitin-like substance (CLS) deposited on eggshells. Similarly, RNAi of LdEcR or Ldusp in L. decemlineata constrained oviposition, decreased the expression of LdUAP1 and LdChS1, and reduced CLS contents in the resultant ovaries. Knockdown of LdUAP1 or LdChS1 caused similar defective phenotypes, i.e., reduced oviposition and CLS contents in the L. decemlineata ovaries. These results, for the first time, indicate that 20E signaling activates choriogenesis in two coleopteran species. Moreover, our findings suggest the deposition of a CLS on the chorions. [ABSTRACT FROM AUTHOR]