Archives of Insect Biochemistry and Physiology最新文献

Calnexin (CNX) and calreticulin (CRT) are two essential endoplasmic reticulum chaperones involved in the folding pathway dedicated to N-glycosylated proteins. The N-glycosylated protein GP64, located in the budded virus envelope of Bombyx mori nucleopolyhedrovirus (BmNPV), plays a key role in viral entry. However, the roles of CNX and CRT in GP64 processing and maturation, as well as in BmNPV infection, remain incompletely understood. In this study, we identified the two genes BmCNX and BmCRT from a B. mori transcriptome database. Spatiotemporal expression profiles showed that BmCNX and BmCRT displayed similar patterns, with expression detected in all tissues and elevated levels in the gonad, trachea, and malpighian tubule, as well as during the egg and larval stages. Following BmNPV infection, the expression of BmCNX and BmCRT was significantly upregulated in both the midgut and BmN cells. Overexpression of BmCNX and BmCRT enhanced BmNPV proliferation and GP64 expression, while knockdown of either gene suppressed both viral proliferation and GP64 expression. Furthermore, GP64 was shown to interact with BmCNX and BmCRT, respectively. These results suggest that BmNPV infection requires both BmCNX and BmCRT to facilitate GP64 expression and promote viral proliferation. This study lays the foundation for further investigation into the roles of endoplasmic reticulum chaperones in response to BmNPV infection.

Helopeltis antonii Signoret is an important sucking pest of cashew and other tree crops. Reverse transcription-quantitative PCR (RT-qPCR) is a widely used technique for analyzing gene expression. The selection of reliable reference genes is critical for accurate quantification of target gene expression using RT-qPCR. There are no studies to identify reliable reference genes or gene expression studies in H. antonii. In this study, the expression stability of eight candidate genes, RPS3A, βTubulin1, RPL13A, 18S, EF1α, Ubiquitin-conjugating enzyme E2 g (UBQ), GAPDH, and TBP, was evaluated across five different nymphal instars and different adult tissues and sexes of H. antonii. Results of stability analysis using multiple algorithms showed that the expression stability of candidate genes varied across different samples. Comprehensive stability ranking with RefFinder showed that RPL13A and TBP were the most stable in different tissues, RPS3A and UBQ were the most stable in different developmental stages, RPS3A and UBQ were the most stable in the two sexes, and UBQ and TUB were the most stable across all samples of H. antonii. Validation of identified stable reference genes (UBQ and the combination of UBQ and TUB) in normalization of two target genes (COX1 and CSP13) expression provided consistent and biologically meaningful results. This study represents the first systematic study on the identification of reliable reference genes in H. antonii and provides the basis for future molecular investigations in this important pest species.

Short-wavelength blue light is commonly encountered in daily life and has been shown to be harmful to the health of organisms. This study aimed to examine the impact of blue light on aging and to explore the potential anti-aging effects of three flavonoids—luteolin, quercetin, and kaempferol—under conditions of blue light exposure. The experiment employed Drosophila melanogaster as a model organism, by feedingvarious concentrations of the three flavonoids and subsequent exposure to short-wavelength blue light. Administration of the highest concentration of the three flavonoids to D. melanogaster was associated with a reduced risk of mortality during adulthood. Male D. melanogaster receiving the highest concentration of flavonoids, as well as those receiving luteolin and quercetin individually, exhibited a reduced initial aging rate (b₀), resulting in an extended mean lifespan and a narrower lifespan distribution compared with the control group. In conclusion, this study demonstrated the effects of flavonoids on the aging process in organisms subjected to blue light. These findings provide important insights into the development of strategies to mitigate aging in the presence of blue-light-induced damage and contribute to a broader understanding of environmental influences on health and aging.

Insect CAPA peptides belong to the family of PRXamide(a) peptides (X, variable amino acids), which are involved in essential physiological functions, including anti-diuresis, desiccation, and myotropic activity. In this study, we identified and characterized a CAPA receptor (CAPA-R) in the western flower thrips (Frankliniella occidentalis) for two endogenous CAPA peptides: CAPA1 (EVQGLFPFPRV) and CAPA2 (QGLIPFPRV). CAPA2 exhibited approximately twice the potency of CAPA1 in activating CAPA-R. Additionally, the modified, shortened peptides, GLFPFPRV and LFPFPRV—derived from CAPA1—activated the receptor more strongly than the native CAPA1. The findings from our previous study, which showed minimal expression of the mRNA responsible for CAPA1, together with the results of the present study demonstrating that the addition of two N-terminal residues, glutamate (E) and valine (V), in CAPA1 interferes with its ability to bind to the receptor, suggest that CAPA2 serves as a primary ligand for the CAPA-R. Through the binding assays using CAPA peptides derived from species across five insect orders—Thysanoptera, Hemiptera, Diptera, Lepidoptera, and Hymenoptera, as well as a non-insect species, a mollusk (slug)—we confirmed that CAPA receptors are exclusively activated by CAPA peptides from insects, regardless of species, and show no activation by other PK peptides. Additionally, we found that F. occidentalis CAPA-R utilizes both intracellular and extracellular Ca²⁺ ions as second messengers in signal transduction triggered by CAPA receptor activation. The short peptide analogs (6-8 residues) derived from the CAPA peptides will be interesting for the development of CAPA agonists targeting the CAPA system to control F. occidentalis populations in the field.

Rice dwarf virus (RDV) exploits virus-induced non-structural proteins Pns10 tubules to overcome membrane or tissue barriers for viral spread within its insect vectors, Nephotettix cincticeps. However, whether vector factors are involved in the motility of virus-containing tubules and, if so, which ones, remains largely unknown. In this study, a high-throughput DUALmembrane yeast two-hybrid system was employed to screen for N. cincticeps proteins interacting with RDV Pns10 tubule. Our results demonstrate that RDV Pns10 interacts with 64 candidate proteins from the vector, which were classified into nine molecular function categories. Furthermore, we confirmed that the expression levels of 14 selected candidate genes, primarily including three energy-related mitochondria genes, three cytoskeleton-related genes, three ribosomal protein synthesis genes, two stress-related DnaJ protein genes, and three intracellular transport-related proteins, were differently modulated upon interaction with RDV Pns10 protein. In conclusion, this study provides new insights into the role and importance of RDV Pns10 interaction with vector proteins during viral infection. It also enhances our understanding of the biochemistry and physiological responses of N. cincticeps to viral infection.

Mitochondrial genome is a powerful tool for studying evolutionary biology, because it is affected by niche adaptation, energy requirements and phenotypic plasticity of organisms. Generalizations about mitogenome evolution are tricky and lead to inconsistent results. The mitogenome can contain lesser mutations than expected and escape mutational meltdown only through the balance of mutation-selection-drift. The state of equilibrium can be achieved by not being significantly affected by any evolutionary process. The reduction of variation by selective sweeps or background selection due to selection and the results of negative purifying selection by the mechanism of genetic drafting exhibit the same effect: reduction of variation on rapidly adapting genes by positive selection and rapid removal of variation from the population due to important functional limitations. Apis mellifera represents a unique model for studying mitogenome evolution, thanks to the characters about adaptation related with life style and biochemistry related with energy requirement. The evolutionary drivers of A. mellifera mitogenomes were tested using 66 mitogenome data representing 21 subspecies. First, processes of mutations/variations were evaluated in nucleotide content and its attitudes. The genome-wide mutational processes were estimated via the abundance of rearrangements and ORF remnants. Selection forces acting on mitogenomes were tested in protein-coding genes. The direction of selection was predicted using a phylogenetic tree- based inferences, and the effects of differences on the possible 3D structures of the proteins were examined. In A. mellifera mitogenomes, the mutation-selection-drift balance was biased to deviation. The balance seems to be maintained by relaxed selection phenomenon, which affects mitogenome quite indirectly. It appears to affect the total mitogenome via copies or “remnants” of the gene, without affecting the mitogenome/mitochondrial gene at the protein level, or even without major changes in the “real” nucleotide sequences of the gene. It does this by inserting repetitive sequences into the d-loop, conserved and possibly functional gene remnants (atp8) into rRNA genes, and affecting the entire genome largely through selective sweeps. Additionally, nd3 gene was positively selected in A. mellifera mitogenomes.

ATP-binding cassette (ABC) transporters constitute a ubiquitous transmembrane protein family that are required for several physiological and metabolic processes in insects. While their structure and function have been discussed in Lepidopteran, Dipteran, Coleopteran, and various other insects, their role in Thysanoptera remains uncharacterized. Here, a genome-wide identification of ABC transporters in Megalurothrips usitatus (MusABCs) were performed using comparative genomics, structural validation, and phylogenetic analysis. Expression analysis and validation were conducted via transcriptomics and qRT-PCR. A total of 53 MusABCs were identified, which were classified into eight subfamilies (ABCA–ABCH), with notable clusters in ABCG (19 genes), ABCC (13 genes), and ABCH (7 genes). The expansion of MusABCC, MusABCG, and MusABCH subfamilies may suggest their critical roles in M. usitatus. Structural analysis suggested MusABCs containing motifs 3, 4, 6, 7, 8 and 10 may be associated with substrate transport and drug efflux. All MusABCs were expressed throughout the development of M. usitatus, with MusABCC3, MusABCG18, and MusABCH3 varying significantly across the stages. Furthermore, MusABCC3, MusABCH3, along with MusABCB1 and MusABCC10 exhibited distinct responses to different insecticides (spinetoram, thiamethoxam, and beta-cypermethrin). MusABCH3 exhibited the most prominent upregulation by 9.33-fold with LC₁₀ of spinetoram and 11.32-fold with LC₃₀ of thiamethoxam, and uniquely upregulated by beta-cypermethrin among the four genes. A total of 41 orthologous MusABCs were identified, and their potential function in the development and insecticide resistance has been discussed. This study provides a comprehensive genomic resource for MusABCs, offering potential targets for management strategies on thrips.