Insect Biochemistry and Molecular Biology最新文献

{"title":"Metabolome changes of Megachile rotundata across pupal stages measured by mass spectrometry-based untargeted metabolomics","authors":"Banani Mondal ,&nbsp;Rikki Walter ,&nbsp;Joseph P. Rinehart ,&nbsp;Kendra J. Greenlee ,&nbsp;Franco Basile","doi":"10.1016/j.ibmb.2026.104513","DOIUrl":"10.1016/j.ibmb.2026.104513","url":null,"abstract":"<div><div>Untargeted metabolomics measurements were conducted via Gas Chromatography-Mass Spectrometry (GC-MS) on both sexes, male and female, of the alfalfa leaf cutting bee, <em>Megachile rotundata</em> during three stages: Prepupae (PP), Red Eye Pupae (RE), and Melanized Pupae (ME). Focusing on the analysis of polar metabolites, results uncovered clear metabolic differences between the three stages of <em>M. rotundata</em>. However, metabolic profiles between sexes within each growth stage were indistinguishable. A total of 189 metabolites were tentatively identified between the three pupal stages studied, and these were used to build a relationship between the data and the observations model (growth stage or sex) with Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA). Specifically, 50 metabolites showed significant changes between stages PP vs. RE, while between stages RE vs. ME, 70 metabolites showed significant changes (OPLS-DA differentiation where VIP &gt;1 and fold change value &gt; 1.5 between groups), pointing to an increase metabolic activity with growth stage progression. Metabolites associated with the different growth stages studied included amino acids, neurotransmitters, carbohydrates and derivatives (phosphorylated, amino, alcohol), nucleotides and organic acids. Measured relative metabolite levels were rationalized in terms of the prevalent metabolic activities at each developmental stage. The PP stage was characterized by an overall low energy consumption state involving the metabolism of amino acids generated via protein degradation. On the other hand, the ME stage was characterized by high levels of metabolites related to the melanization process (tyrosine, DOPA) as well as phosphorylated carbohydrates, amino acids, nucleic acids and neurotransmitters indicating a state of high energy consumption and structural changes.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"189 ","pages":"Article 104513"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146176832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The structural and transcriptional basis of carboxylesterase-mediated λ-cyhalothrin resistance in Spodoptera litura","authors":"Jun Li,&nbsp;Xiaodan Huang,&nbsp;Mengqing Deng,&nbsp;Jiemeng Chen,&nbsp;Linjie Zhou,&nbsp;Xiyue Xu,&nbsp;Xinyu Zhao,&nbsp;Rui Peng,&nbsp;Zhiming Yang,&nbsp;Kai Lu","doi":"10.1016/j.ibmb.2026.104518","DOIUrl":"10.1016/j.ibmb.2026.104518","url":null,"abstract":"<div><div>Pyrethroid resistance in Lepidopteran pests poses a serious threat to sustainable pest management. Although carboxylesterases (COEs) contribute to metabolic resistance, their precise functional roles and regulation remain obscure. Here, a <em>λ</em>-cyhalothrin-resistant strain of the tobacco cutworm <em>Spodoptera litura</em> (93.29-fold resistance) showed significantly increased COE activity. Synergism assays using triphenyl phosphate confirmed COE involvement, increasing <em>λ</em>-cyhalothrin toxicity with synergistic ratios of 2.26 and 2.33 in susceptible and resistant strains. Three COE genes (<em>COE052</em>, <em>COE054</em>, and <em>COE066</em>) were markedly overexpressed in the resistant strain, with midgut expression upregulated by 140.63-, 102.60-, and 99.98-fold, respectively. RNA interference revealed that <em>COE052</em> and <em>COE066</em> are essential for resistance, while <em>COE054</em> knockdown had no effect, likely due to compensatory overexpression of the other two COEs. Heterologous expression in bacteria demonstrated that all three COEs confer increased <em>λ</em>-cyhalothrin tolerance by 3.13-, 2.26-, and 3.29-fold and exhibit antioxidant activity. <em>In vitro</em> metabolism assays confirmed their capacity to degrade <em>λ</em>-cyhalothrin, with COE066 displaying the highest metabolic efficiency (47.20%). Molecular docking and mutagenesis identified Asn446 and His447 in COE066 as key residues for <em>λ</em>-cyhalothrin binding, metabolism, and antioxidant function. His447 was particularly critical: its mutation decreased binding free energy from −34.96 to 3.28 kcal mol⁻¹, reduced metabolic efficiency from 51.10% to 14.39%, and significantly impaired antioxidant activity. Furthermore, the transcription factor HNF4 was found to regulate the expression of all three COEs, establishing an HNF4–COE regulatory axis underlying <em>λ</em>-cyhalothrin resistance. This study elucidates the mechanism of COE-mediated pyrethroid resistance and highlights potential targets for resistance management.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"189 ","pages":"Article 104518"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146224746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel-miR-932 targets BgNeverland to regulate 20-hydroxyecdysone synthesis in Blattella germanica: Prospective target for pest control","authors":"Yue Zhang ,&nbsp;Fei Yu ,&nbsp;Xian Huang ,&nbsp;Xiaoying Lv ,&nbsp;Xunxun Wang ,&nbsp;Zexin Gao ,&nbsp;Xianyi Wang","doi":"10.1016/j.ibmb.2025.104474","DOIUrl":"10.1016/j.ibmb.2025.104474","url":null,"abstract":"<div><div>miRNAs critically regulate hormonal signaling to ensure precise spatiotemporal control of metamorphosis and reproduction in insects, highlighting their potential as pest control targets. <em>Blattella germanica</em>, is a major indoor sanitary pest that threatens human and domestic animal health. However, the miRNA expression profiles and their systematic functions in the hormonal signaling pathways remain largely uncharacterized in <em>B. germanica</em>. Transcriptomic analysis of the nymph-to-adult transition in <em>B. germanica</em> revealed that both downregulated differentially expressed genes and the target genes of differentially expressed miRNAs were significantly enriched in insect hormone biosynthesis pathways. RNA interference (RNAi)-mediated silencing of six key 20E biosynthesis genes (<em>BgNeverland</em>, <em>BgSpook</em>, <em>BgPhantom</em>, <em>BgDisembodied</em>, <em>BgShadow</em>, and <em>BgShade</em>) resulted in molting defects and increased mortality in nymphs. Based on bioinformatic predictions and omics data, we identified miRNAs potentially targeting 20E biosynthesis genes. Subsequent dual-luciferase reporter assays, along with agomir and antagomir injection experiments, confirmed that novel-miR-932 negatively regulates <em>BgNeverland</em>. Both oversupply and inhibition of novel-miR-932 led to elevated nymphal mortality. Supplementation with exogenous 20E effectively rescued the increased mortality induced by novel-miR-932 agomir injection. Furthermore, either oversupply of miR-932 or silencing of <em>BgNeverland</em> resulted in a reduction in lipid content, consequently compromising female fecundity. These results implicate miRNAs that target 20E pathway genes as potential targets for novel pest control strategies.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104474"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145861668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trichlorfon induces damage of growth and development of Bombyx mori through ferroptosis pathway","authors":"Wen Zhang ,&nbsp;Huang Lin ,&nbsp;Ziqin Xiao ,&nbsp;Dongxu Shen ,&nbsp;Dingguo Xia ,&nbsp;Zhiyong Qiu ,&nbsp;Xuelian Zhang ,&nbsp;Qiaoling Zhao","doi":"10.1016/j.ibmb.2026.104488","DOIUrl":"10.1016/j.ibmb.2026.104488","url":null,"abstract":"<div><div>Trichlorfon (TCF), an organophosphorus pesticide, has long been used in agriculture as an insecticide for crop protection. However, its residual presence has caused significant economic losses to the sericulture industry, hindering the development of <em>Bombyx mori</em> (<em>B</em>. <em>mori</em>) farming. Although previous studies have investigated the toxicity of TCF to silkworms, the detailed toxic effects and molecular mechanisms remain poorly understood. In this study, the potential molecular targets and mechanisms of TCF-induced injury in silkworms were investigated in <em>vivo</em> and in <em>vitro</em> by combining RNA sequencing, qRT-PCR and other techniques. It is found that TCF exposure leads to damage of growth and development in silkworms, as evidenced by reduced body weight, increased mortality, and decline of cluster, cocooning, pupation and egg production. Further RNA sequencing analysis identified several differentially expressed genes, particularly <em>LOC101744260</em>, as well as altered pathways, notably the glutamine metabolism pathway—both of which are closely associated with ferroptosis. In <em>vivo</em> and in <em>vitro</em> experiments have confirmed that the expression levels of ferroptosis-related genes, including <em>Fer HCH</em>, <em>Fer 2LCH</em>, <em>Keap1</em>, <em>Tf</em>, <em>Gtpx</em> and <em>SOD1</em> exhibited significant changes in expression levels. These changes are accompanied by elevated intracellular Fe²⁺ and Fe³⁺ levels and oxidative stress. Moreover, N-acetylcysteine (NAC) treatment partially reverses TCF-induced growth and developmental impairments at the individual and cellular levels. Taken together, these results indicate for the first time that TCF exposure induces damage of growth and development in silkworms by activating the ferroptosis pathway. This study provides a new insight into the toxic mechanisms of TCF in silkworms and offers a theoretical basis for the prevention and control of pesticide pollution in silkworms industry.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104488"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145916287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional characterization of voltage-gated sodium channels in two mirid pests and identification of kdr mutations in pyrethroid resistant Lygus lineolaris population","authors":"Yuzhe Du ,&nbsp;Shane Scheibener ,&nbsp;Yu-Cheng Zhu ,&nbsp;Omaththage P. Perera ,&nbsp;Gadi V.P. Reddy ,&nbsp;Boris S. Zhorov","doi":"10.1016/j.ibmb.2026.104486","DOIUrl":"10.1016/j.ibmb.2026.104486","url":null,"abstract":"<div><div><em>Lygus lineolaris</em> and <em>Lygus hesperus</em> are economically important pests that cause substantial damage to wide variety of crops in the United States. In this study, we isolated 17 full-length voltage-gated sodium channels cDNA clones encoding 14 unique splicing variants from a susceptible strain of <em>L. hesperus</em> (sLhNav), two variants from a susceptible <em>L. lineolaris</em> strain (sLlNav)<em>,</em> and 8 clones encoding 7 variants from a pyrethroid-resistant <em>L. lineolaris</em> population (rLlNav), based on the usage of 12 alternative exons. Functional expression in <em>Xenopus</em> oocytes revealed that 11 sLh/LlNav variants produced sodium currents suitable for electrophysiological analysis, which displayed distinct gating properties. Notably, Nav variants lacking exon b generated significantly larger currents compared to those including exon b. We also identified A-to-I editing events in both <em>Lygus</em> Navs, and a key finding was the identification of three <em>kdr</em> mutations in rLlNav variants, L1023 F/S in segment IIS6 and L934I in the IIS4-S5 linker (corresponding to L1014F, L1014S and L925I in housefly Nav), all of which have been previously associated with pyrethroid resistance in other insect species. This is the first report of these mutations in resistant <em>L. lineolaris</em> populations. Together with earlier reports of enhanced metabolic detoxification, our findings suggest a dual resistance strategy in <em>L. lineolaris,</em> involving both target-site insensitivity and elevated detoxification enzyme activity. The comprehensive characterization of sodium channel variants in both <em>Lygus</em>, along with the identification of L1023 F/S and L934I mutations<em>,</em> provides valuable insight into Nav diversity in <em>Lygus</em> species and the molecular basis of pyrethroid resistance in <em>L. lineolaris</em>.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104486"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145916295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trachealess, a bHLH-PAS transcription factor, is an upstream regulator of 20-hydroxyecdysone signaling essential for molting in Henosepilachna vigintioctopunctata","authors":"Junna Liu ,&nbsp;Qi Chen ,&nbsp;June-Sun Yoon ,&nbsp;Mujuan Guo ,&nbsp;Chunxiao Yang ,&nbsp;Xuguo Zhou ,&nbsp;Youjun Zhang ,&nbsp;Huipeng Pan","doi":"10.1016/j.ibmb.2026.104493","DOIUrl":"10.1016/j.ibmb.2026.104493","url":null,"abstract":"<div><div>The steroid hormone 20-hydroxyecdysone (20E) is the central regulator of insect molting, yet the upstream transcription factors controlling its pathway remain poorly characterized. Here, we investigate the role of the bHLH-PAS transcription factor Trachealess (HvTrh) in the 28-spotted ladybeetle, <em>Henosepilachna vigintioctopunctata</em>. <em>HvTrh</em> was ubiquitously expressed during larval development, with peak transcript levels in the pupal stage. RNAi-mediated silencing of <em>HvTrh</em> induced severe molting defects and high mortality across all larval instars. This was associated with a significant reduction in 20E titers and the suppression of key 20E pathway genes. The resulting molting defects were not rescued by exogenous 20E, indicating a disruption of tissue competence. Histological analysis confirmed that <em>HvTrh</em> knockdown impaired chitin deposition and new cuticle remodeling. Among the downregulated genes, <em>HvE75</em> was the most strongly suppressed. Mechanistically, we demonstrated that HvTrh directly activates the <em>HvE75</em> promoter by binding to a specific central nervous system midline element (CME), as validated by dual-luciferase reporter assays and electrophoretic mobility shift assays. Our findings establish HvTrh as a critical upstream regulator of insect molting, proposing a model where it governs the 20E signaling cascade, at least in part, through the direct transcriptional control of <em>HvE75</em>.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104493"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145958221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A cuticular protein essential for sperm dimorphism and male fertility in Bombyx mori","authors":"Zhongwei Li ,&nbsp;Bing Zhang ,&nbsp;Chenyue Zhao ,&nbsp;Yanyan Wang ,&nbsp;Ruoke Wang ,&nbsp;Camilo Ayra-Pardo ,&nbsp;Yunchao Kan ,&nbsp;Dandan Li","doi":"10.1016/j.ibmb.2025.104476","DOIUrl":"10.1016/j.ibmb.2025.104476","url":null,"abstract":"<div><div>In Lepidoptera, sperm develop as two distinct types: fertile eupyrene and non-fertile apyrene sperm. Although apyrene sperm do not fertilize eggs, they support fertilization through auxiliary functions. However, the molecular mechanisms underlying this dimorphism remain poorly understood. Here, we identify the Cuticular Protein Hypothetical 19 precursor (<em>BmorCPH19</em>) gene as essential for sperm development in <em>Bombyx mori</em>. Using 70 μm cell strainers, we isolated transcriptionally active apyrene spermatocytes and an eupyrene-enriched fraction containing mature sperm bundles from 3-day-old pupal testes, when morphs are distinct and separable. Transcriptomic profiling revealed 737 differentially expressed genes, including <em>BmorCPH19</em>, unexpectedly enriched in the eupyrene fraction —suggesting a novel role beyond cuticle-related activity. qRT-PCR analysis showed that <em>BmorCPH19</em> expression in the testes peaks during eupyrene differentiation in the 6-day-old fourth-instar larva and the 1-day-old prepupa. Isolated sperm morphs confirmed consistent <em>BmorCPH19</em> enrichment in eupyrene sperm, with maximal accumulation in late pupae. Functional assays demonstrated its role in sperm fate: RNAi knockdown increased the apyrene-to-eupyrene ratio, while overexpression favored eupyrene sperm but impaired fertility, yielding more non-viable eggs. These findings identify BmorCPH19 as the first cuticular protein essential for lepidopteran sperm dimorphism and reveal its dosage-sensitive role in balancing sperm differentiation and reproductive success, offering a potential molecular target for pest control.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104476"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The cytochrome P450s CYP6CY3 and CYP6CY4 confer resistance to flupyradifurone in the green peach aphid Myzus persicae","authors":"Jun Yuan ,&nbsp;Bin Zeng ,&nbsp;Benjamin J. Hunt ,&nbsp;Bartlomiej J. Troczka ,&nbsp;Xingzhi Xiao ,&nbsp;James Gardner ,&nbsp;Faye Papadimitriou ,&nbsp;Jason Charamis ,&nbsp;Aris Ilias ,&nbsp;Adam Pym ,&nbsp;Konstantinos Mavridis ,&nbsp;Dieudonné T. Tshitenge ,&nbsp;Ralf Nauen ,&nbsp;John Vontas ,&nbsp;John T. Margaritopoulos ,&nbsp;Xianhui Yin ,&nbsp;Chris Bass","doi":"10.1016/j.ibmb.2026.104487","DOIUrl":"10.1016/j.ibmb.2026.104487","url":null,"abstract":"<div><div>The green peach aphid, <em>Myzus persicae</em>, is an economically important crop pest that has evolved resistance to numerous insecticides used for control. Recent research has shown that populations of <em>M. persicae</em> in Greece have evolved resistance to flupyradifurone, a butenolide insecticide that acts as a reversible agonist on insect nicotinic acetylcholine receptors (nAChRs). However, the genetic mechanisms underpinning resistance remain unclear. Here we used transcriptomic profiling in combination with <em>in vivo</em> and <em>in vitro</em> functional approaches to show that flupyradifurone resistance in <em>M. persicae</em> is conferred by enhanced expression of the P450 genes <em>CYP6CY3</em> and <em>CYP6CY4</em>. High levels of flupyradifurone resistance were observed in <em>M. persicae</em> clones from Greece and France, including in a clone that predates the registration of this insecticide. Synergist bioassays with piperonyl butoxide, an inhibitor of P450s, suggested resistance was mediated, in part, by enhanced P450 activity. Subsequent, transcriptome profiling identified several P450s that were overexpressed in the resistant <em>M. persicae</em> clones compared to susceptible clones. Functional characterisation of these P450s revealed that only CYP6CY3 and CYP6CY4 confer resistance <em>in vivo</em> and metabolise flupyradifurone <em>in vitro</em>. In two clones with extremely high levels of resistance to flupyradifurone, overexpression of these P450s was accompanied by the R81T mutation in the β1 subunit of the nAChR, known to confer resistance to neonicotinoids and cross-resistance to flupyradifurone. These findings provide new insight into the mechanisms of resistance to flupyradifurone and reveal how generalist P450s can be preadapted to confer cross-resistance to diverse insecticides.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104487"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145916342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TostOBP12 mediates the olfactory response to host volatiles in the parasitoid wasp Trichogramma ostriniae","authors":"Xiang-xin Kong ,&nbsp;Hou-xuan Zhang ,&nbsp;Hong-yu Liang ,&nbsp;Han Xiao ,&nbsp;Yu-qin Wang ,&nbsp;Shuang Gang ,&nbsp;Hui Dong","doi":"10.1016/j.ibmb.2026.104491","DOIUrl":"10.1016/j.ibmb.2026.104491","url":null,"abstract":"<div><div><em>Trichogramma</em> wasps are widely utilized as critical biological control agents in agricultural systems. Its efficacy relies on detecting host-derived chemical cues, yet the key molecular determinants underlying this process remain elusive. Here, we demonstrate that the odorant-binding protein TostOBP12 is indispensable for the host-seeking behavior of <em>T. ostriniae</em>. Interspecific behavioral assays revealed that only <em>T. ostriniae</em> exhibited significantly enhanced parasitism driven by the host sex pheromone. <em>TostOBP12</em> was identified as the most highly expressed OBP in female heads. Molecular docking and competitive binding assays confirmed its high and broad affinity for both sex pheromones ((Z)-12:14AC and (E)-12:14AC) and egg surface compounds. Crucially, RNAi-mediated silencing of <em>TostOBP12</em> completely abolished the wasp's behavioral response to sex pheromones without affecting its development, confirming its essential <em>in vivo</em> function. Our findings reveal a key molecular sensor in a tritrophic interaction and provide a promising target for enhancing biocontrol efficacy.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104491"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Starvation induces a transition from autophagy to apoptosis via the ER-Ca2+-calpain signaling axis in the fat body of Bombyx mori","authors":"Jialu Cheng ,&nbsp;Sheng Zhang ,&nbsp;Haoyi Gu ,&nbsp;Xueling Qin ,&nbsp;Bing Li","doi":"10.1016/j.ibmb.2026.104494","DOIUrl":"10.1016/j.ibmb.2026.104494","url":null,"abstract":"<div><div>Nutritional stress is a common environmental challenge for insects in nature. As a central organ of energy metabolism, the fat body plays a crucial role in maintaining energy homeostasis. However, the mechanisms by which the fat body regulates programmed cell death (PCD) during energy crises remain unclear. In this study, the fat body of <em>Bombyx mori</em> was used as a model to investigate the regulatory mechanisms underlying PCD transitions induced by sustained energy depletion. The results indicated that starvation caused a significant reduction in adenosine triphosphate (ATP), rapid depletion of glycogen and triglycerides, and marked inhibition of the endoplasmic reticulum (ER) calcium pump enzyme SERCA. Concurrently, it upregulated the expression of the calcium channel IP3R. These combined effects led to Ca²⁺ efflux from the ER calcium stores and cytoplasmic Ca²⁺ overload. Intracellular Ca²⁺ levels significantly increased, followed by a decrease during prolonged starvation, paralleling changes in calpain activity and accompanied by the upregulation of the proapoptotic protein NtATG5. Short-term starvation promoted autophagy by significantly increasing LC3-II and ATG5 expression, whereas prolonged starvation promoted calpain-mediated cleavage of ATG5 to generate NtATG5 and activated caspase-3, leading to apoptosis. Furthermore, the IP3R inhibitor 2-APB significantly suppressed starvation-induced calcium signaling, autophagy, and apoptosis. This study reveals the regulatory mechanism by which the <em>Bombyx mori</em> fat body modulates PCD under starvation stress via the ER-Ca²⁺-calpain signaling pathway, providing crucial insights into how nutritional deprivation causes physiological damage in insects.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"188 ","pages":"Article 104494"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}