Archives of Insect Biochemistry and Physiology最新文献

The cotton-melon aphid Aphis gossypii Glover is an important agricultural pest that causes severe damage. Cytochrome P450 monooxygenases (P450s) are involved in the metabolism of insecticides and plant secondary metabolites, making A. gossypii widespread and challenging to control. Hap1, Hap3, and Hap4 are considered to be the domain haplotypes of A. gossypii, and high-quality genome assemblies are now available. In this study, 58 P450 genes were identified in A. gossypii, which were classified into four CYP clans: 9 P450 genes belong to the CYP2 clan, 26 P450 genes belong to the CYP3 clan, 17 P450 genes belong to the CYP4 clan, and 6 P450 genes belong to the mitochondrial clans. P450 genes are often arranged in clusters on chromosomes, with more than half distributed on chromosome A1 in A. gossypii. Most insecticide resistance-related P450 genes in A. gossypii are clustered with conserved gene structures among the Hap1, Hap3, and Hap4. Still, they show different expression levels among the three haplotypes of A. gossypii. Five structural variants of the P450 gene among Hap1, Hap3, and Hap4 were characterized in A. gossypii; not all structural variants exhibit regulatory effects on P450 gene expression. The largest P450 gene cluster includes five A. gossypii P450 4C1 genes, with conserved gene structure among the three haplotypes but varying sizes of the three introns, which have a marked effect on gene expression. These findings provide a valuable resource for further investigations into population differentiation and pesticide resistance evolution in A. gossypii.

Understanding the genetic basis of pest resistance to Bacillus thuringiensis (Bt) (Berliner) (Bacillales: Bacillaceae) toxins is important for optimizing integrated pest management (IPM). In this study, we characterized a strain (Cry1S1000) of Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae) highly resistant to Bt using genetic crosses and dose-response bioassays. This strain exhibited >13,333-fold resistance to Cry1Ac toxin, which was conferred by a single autosomal locus and inherited in a completely recessive manner. Cross-resistance profiling revealed high-level resistance to Cry1Aa (>115-fold) and Cry1Ab (491-fold), but only minimal resistance to Cry1C (5-fold). These findings elucidate the evolution and mechanisms of Bt resistance in P. xylostella and provide a foundation for developing targeted resistance management tactics to sustain Bt efficacy.

While there are many amino acids in nature, all biological proteins are made of the 20 standard amino acids, which occur in virtually all organisms, including viruses. Here, we move beyond proteins to consider the broader biological significance of amino acids in insects. Some amino acids, particularly glycine, act in insect mating systems. We note that insects have biological requirements for essential amino acids, compounds that are required by many species, but must be acquired by consumption or donated by microbiome components. Dietary amino acid requirements differ among insect groups and species. Some insect species rely on tasting and recalling amino acid tastes in their natural foraging areas. An unknown number of microbiome components provide essential amino acids to their hosts. Together, sensory detection, transport systems, and microbial provisioning position amino acids as multifunctional regulators that connect molecular physiology to behavior and ecology. We conclude by highlighting research priorities—mechanistic studies of transport and sensing, life-stage comparative analyses, and integrative metabolomic approaches—to resolve how amino acids shape insect fitness and to translate these insights for pollinator health, pest management, and edible-insect nutrition.

The Gené's organ (GO) secretes a waxy substance on eggs that reduces water loss and has antimicrobial properties. The current study evaluated morphological and histochemical aspects of GO in Amblyomma sculptum on the 1st day of oviposition (DOV), as well as the neutral lipids found in the organ and wax. The morphological results showed that the glandular cells of the GO synthesize proteins. On the other hand, punctually, necrotic glandular cells and mitochondria were noted, with initial signs of degeneration, confirming the beginning of senescence of these cells. The analysis of the neutral lipids showed that the cranial and caudal glands have identical profiles, thus indicating that the individualization between them is simply anatomical. Still, the lipids found in the cranial and caudal glands were the same found in the wax showing that OG has an important function in the final synthesis of egg wax.

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.

This study investigates the metabolomic profile of the Parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), under thermal stress conditions. This beetle is an effective biological control agent against the invasive and toxic weed Parthenium hysterophorus. Metabolomic analysis identified 1277 metabolites, with significant variation observed among control (27°C), heat stress (35°C), and cold stress (15°C) conditions, highlighting distinct metabolic responses to temperature extremes. Heat exposure yielded the greatest number of unique metabolites, indicating elevated metabolic activity, while cold stress also induced distinct compounds, reflecting specialized adaptive responses. Enrichment analysis revealed consistent upregulation of alkaloids, lipids, and amino acid-related metabolites across all conditions, suggesting their protective roles in membrane stability, cellular signaling, and stress mitigation. Pathway analysis showed that lipid metabolism (glycerophospholipids and sphingolipids) and amino acid pathways (tryptophan, phenylalanine, and histidine) were universally affected, likely reflecting adaptive membrane remodeling and stress-response mechanisms that support beetle survival under fluctuating thermal conditions. Control beetles primarily utilized glutathione and carbohydrate metabolism, whereas heat-stressed beetles exhibited enrichment of nitrogen metabolism and amino acid catabolic pathways. In contrast, cold stress uniquely altered nucleotide metabolism and vitamin B6 pathways, suggesting distinct metabolic strategies in response to temperature extremes. Overall, these findings demonstrate that Parthenium beetles undergo extensive, condition-specific metabolic reprogramming to maintain cellular homeostasis and adapt to thermal stress.

The ATP-binding cassette (ABC) transporter superfamily is one of the largest groups of membrane proteins, involved in phase III of the detoxification process and plays important roles in insecticide resistance. In this study, A total of 69 ABC transporter proteins genes was identified based on genome and transcriptome, including 18 ABCA genes, 6 ABCB genes, 11 ABCC genes, 5 ABCD genes, 3 ABCF genes, and 26 ABCG genes in Eriosoma lanigerum. Among the 69 ABC transporters, 15 are classified as full transporters, while 27 are identified as half transporters. Within the ABCA and ABCG subfamilies, there are 14 and 5 proteins, respectively, that possess only the NBD domain and lack the TMD domain, indicating that these proteins do not perform transmembrane functions. Two notable ABC transporters have recently been identified in the ABC transporters of E. lanigerum. ElABCC1 features 4 NBDs and 4 TMDs, whereas ElABCG21 comprises 3 NBDs and 3 TMDs. In this study, the ElABCG2 gene was cloned, revealing that its full-length sequence is 2082 bp and that it belongs to the category of half transporters. Temporal and spatial expression analyses indicate that the expression level of this gene significantly increases during the growth of the instar stages. Furthermore, it is expressed in the head, thorax, and abdomen, with expression levels exhibiting an upward trend. The RNAi technique was employed to specifically knock out the ElABCG2 gene. Subsequently, E. lanigerum were exposed to the median lethal concentrations of imidacloprid and thiamethoxam. The results demonstrated that following the knockout of this gene, the sensitivity of E. lanigerum to imidacloprid increased significantly, while no notable change was observed in their sensitivity to thiamethoxam. This suggests that the ElABCG2 gene may play a crucial role in the detoxification process of E. lanigerum against imidacloprid. However, the specific detoxification mechanism warrants further investigation.

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.