With the aim of identifying Cry proteins that would be useful in the management of the economically important lepidopteran pest Helicoverpa armigera, the larvicidal activities of binary combinations (1:1 ratios) of six Cry proteins (Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ca, Cry2Aa and Cry9Aa) were evaluated against H. armigera neonate larvae using droplet feeding bioassays. Determination of the LD50 values of individual Cry proteins and mixtures of Cry proteins enabled assessment of the nature of the interactions between Cry proteins in H. armigera. There was a more than 6000-fold difference between the LD50 values of the Cry protein mixture with the lowest larvicidal activity and the mixture with the highest larvicidal activity. Cry1Ac and Cry2Aa mixtures and Cry1Ac and Cry1Ca mixtures had the highest larvicidal activity against H. armigera, with Cry1Ac and Cry1Ca interacting synergistically. Differences in the magnitudes of the antagonistic interactions observed for different binary mixtures of Cry1A-class proteins are consistent with a model of more than one binding site for some Cry1A-class proteins in H. armigera. Binary combinations of Cry1A-class and Cry9Aa proteins showed additive interactions in neonate larvae of H. armigera, whereas combinations of Cry1Ca and Cry9Aa were statistically synergistic. The results suggest that products containing mixtures of Cry1Ac and Cry2Aa or Cry1Ac and Cry1Ca may be useful components of H. armigera pest management programs.
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http://dx.doi.org/10.1016/j.jip.2014.06.005 | DOI Listing |
Insects
December 2024
Programa de Pós-Graduação em Biodiversidade e Saúde, Instituto Oswaldo Cruz-Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro 21040-900, RJ, Brazil.
The high pathogenic activity of () strains against various insect orders has positioned it as the most effective, environmentally safe, and sustainable approach to integrated insect management. We aimed to identify strains capable of effectively controlling the housefly , a species of significant medical, veterinary, and public health concern. Twelve strains from Macapá, Brazil, were tested against housefly larvae.
View Article and Find Full Text PDFPhilos Trans R Soc Lond B Biol Sci
January 2025
MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
The mammalian cryptochrome proteins (CRY1 and CRY2) are transcriptional repressors most notable for their role in circadian transcriptional feedback. Not all circadian rhythms depend on CRY proteins, however, and the CRY proteins are promiscuous interactors that also regulate many other processes. In cells with chronic CRY deficiency, protein homeostasis is highly perturbed, with a basal increase in cellular stress and activation of key inflammatory signalling pathways.
View Article and Find Full Text PDFPhilos Trans R Soc Lond B Biol Sci
January 2025
Department of Infectious Disease, Imperial College London, London SW7 2AZ, UK.
The within-host environment changes over circadian time and influences the replication and severity of viruses. Genetic knockout of the circadian transcription factors CRYPTOCHROME 1 and CRYPTOCHROME 2 (/; CKO) leads to altered protein homeostasis and chronic activation of the integrated stress response (ISR). The adaptive ISR signalling pathways help restore cellular homeostasis by downregulating protein synthesis in response to endoplasmic reticulum overloading or viral infections.
View Article and Find Full Text PDFBMC Med Genomics
January 2025
Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran.
Background: The growth in obesity and rates of abdominal obesity in developing countries is due to the dietary transition, meaning a shift from traditional, fiber-rich diets to Westernized diets high in processed foods, sugars, and unhealthy fats. Environmental changes, such as improving the quality of dietary fat consumed, may be useful in preventing or mitigating the obesity or unhealthy obesity phenotype in individuals with a genetic predisposition, although this has not yet been confirmed. Therefore, in this study, we investigated how dietary fat quality indices with metabolically healthy obesity (MHO) or metabolically unhealthy obesity (MUO) based on the Karelis criterion interact with genetic susceptibility in Iranian female adults.
View Article and Find Full Text PDFCurr Biol
January 2025
Basic Forestry and Plant Proteomics Research Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address:
The CRY2 photoreceptor is known to form homotetramers that bind to transcription regulators to affect gene expression in response to light. A new study provides evidence that the CRY2 monomer binds different transcription regulators to affect gene expression in darkness, suggesting that photoreceptors change activity in response to light.
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