Compounds classified as benzoylphenylurea (BPU), such as diflubenzuron (DFB), are used as insecticides. Although BPU disrupts molting by inhibiting chitin biosynthesis and exhibits insecticidal activity, their exact mode of action remains unknown. Since epidermal cells proliferate and morphologically change from squamous to columnar cells during the early stages of insect molting, we speculate that a transition similar to that from epithelium to mesenchyme occurs and that BPU may inhibit this transition. Here, we addressed this possibility. We found that DFB decreases actin expression in insect cells (the tissue cultures of insect integument). Detailed analysis in Schneider S2 cells reveals that DFB inhibits the expression of actin isoforms (Act5C and Act42A) and the Drosophila ortholog of myocardin-related transcription factor (Mrtf), leading to cell growth suppression. Proteomics identified the Drosophila ortholog of prohibitin (Phb1D and Phb2E) as one of the DFB-binding proteins. DFB inhibits the interaction between Phb1D and Phb2E and induces mitochondrial dysfunction. The knock-down of Phb2E suppresses the expression of Act5C, Act42A, and Mrtf, leading to cell growth inhibition. Thus, the disruption of Phb function is a possible novel target of DFB.
{"title":"Novel ability of diflubenzuron as an inhibitor of mitochondrial function","authors":"Kotaro Mori , Yoshiaki Nakagawa , Bunta Watanabe , Hiroshi Miyata , Tsuyoshi Morita , Ken'ichiro Hayashi","doi":"10.1016/j.ibmb.2024.104088","DOIUrl":"10.1016/j.ibmb.2024.104088","url":null,"abstract":"<div><p>Compounds classified as benzoylphenylurea (BPU), such as diflubenzuron (DFB), are used as insecticides. Although BPU disrupts molting by inhibiting chitin biosynthesis and exhibits insecticidal activity, their exact mode of action remains unknown. Since epidermal cells proliferate and morphologically change from squamous to columnar cells during the early stages of insect molting, we speculate that a transition similar to that from epithelium to mesenchyme occurs and that BPU may inhibit this transition. Here, we addressed this possibility. We found that DFB decreases actin expression in insect cells (the tissue cultures of insect integument). Detailed analysis in Schneider S2 cells reveals that DFB inhibits the expression of actin isoforms (Act5C and Act42A) and the Drosophila ortholog of myocardin-related transcription factor (Mrtf), leading to cell growth suppression. Proteomics identified the Drosophila ortholog of prohibitin (Phb1D and Phb2E) as one of the DFB-binding proteins. DFB inhibits the interaction between Phb1D and Phb2E and induces mitochondrial dysfunction. The knock-down of Phb2E suppresses the expression of Act5C, Act42A, and Mrtf, leading to cell growth inhibition. Thus, the disruption of Phb function is a possible novel target of DFB.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0965174824000195/pdfft?md5=bdb1de11844a4c6f8677413c4e8bcab7&pid=1-s2.0-S0965174824000195-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139717176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1016/j.ibmb.2024.104085
J. Joe Hull , Chan C. Heu , Roni J. Gross, Dannialle M. LeRoy, Inana X. Schutze, Daniel Langhorst, Jeffrey A. Fabrick, Colin S. Brent
In most holometabolous insects, sex differentiation occurs via a hierarchical cascade of transcription factors, with doublesex (dsx) regulating genes that control sex-specific traits. Although less is known in hemimetabolous insects, early evidence suggests that substantial differences exist from more evolutionarily advanced insects. Here, we identified and characterized dsx in Lygus hesperus (western tarnished plant bug), a hemipteran pest of many agricultural crops in western North America. The full-length transcript for L. hesperus dsx (Lhdsx) and several variants encode proteins with conserved DNA binding and oligomerization domains. Transcript profiling revealed that Lhdsx is ubiquitously expressed, likely undergoes alternative pre-mRNA splicing, and, unlike several model insects, is sex-biased rather than sex-specific. Embryonic RNA interference (RNAi) of Lhdsx only impacted sex development in adult males, which lacked both internal reproductive organs and external genitalia. No discernible impacts on adult female development or reproductivity were observed. RNAi knockdown of Lhdsx in nymphs likewise only affected adult males, which lacked the characteristic dimorphic coloration but had dramatically elevated vitellogenin transcripts. Gene knockout of Lhdsx by CRISPR/Cas9 editing yielded only females in G0 and strongly biased heterozygous G1 offspring to females with the few surviving males showing severely impaired genital development. These results indicate that L. hesperus male development requires Lhdsx, whereas female development proceeds via a basal pathway that functions independently of dsx. A fundamental understanding of sex differentiation in L. hesperus could be important for future gene-based management strategies of this important agricultural pest.
{"title":"Doublesex is essential for masculinization but not feminization in Lygus hesperus","authors":"J. Joe Hull , Chan C. Heu , Roni J. Gross, Dannialle M. LeRoy, Inana X. Schutze, Daniel Langhorst, Jeffrey A. Fabrick, Colin S. Brent","doi":"10.1016/j.ibmb.2024.104085","DOIUrl":"10.1016/j.ibmb.2024.104085","url":null,"abstract":"<div><p>In most holometabolous insects, sex differentiation occurs via a hierarchical cascade of transcription factors, with <em>doublesex</em> (<em>dsx</em>) regulating genes that control sex-specific traits. Although less is known in hemimetabolous insects, early evidence suggests that substantial differences exist from more evolutionarily advanced insects. Here, we identified and characterized <em>dsx</em> in <em>Lygus hesperus</em> (western tarnished plant bug), a hemipteran pest of many agricultural crops in western North America. The full-length transcript for <em>L. hesperus dsx</em> (<em>Lhdsx</em>) and several variants encode proteins with conserved DNA binding and oligomerization domains. Transcript profiling revealed that <em>Lhdsx</em> is ubiquitously expressed, likely undergoes alternative pre-mRNA splicing, and, unlike several model insects, is sex-biased rather than sex-specific. Embryonic RNA interference (RNAi) of <em>Lhdsx</em> only impacted sex development in adult males, which lacked both internal reproductive organs and external genitalia. No discernible impacts on adult female development or reproductivity were observed. RNAi knockdown of <em>Lhdsx</em> in nymphs likewise only affected adult males, which lacked the characteristic dimorphic coloration but had dramatically elevated <em>vitellogenin</em> transcripts. Gene knockout of <em>Lhdsx</em> by CRISPR/Cas9 editing yielded only females in G<sub>0</sub> and strongly biased heterozygous G<sub>1</sub> offspring to females with the few surviving males showing severely impaired genital development. These results indicate that <em>L. hesperus</em> male development requires <em>Lhdsx</em>, whereas female development proceeds via a basal pathway that functions independently of <em>dsx</em>. A fundamental understanding of sex differentiation in <em>L. hesperus</em> could be important for future gene-based management strategies of this important agricultural pest.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139659091","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}
Pub Date : 2024-01-29DOI: 10.1016/j.ibmb.2024.104087
Myeongjin Kim , Mi Young Noh , Seulgi Mun , Subbaratnam Muthukrishnan , Karl J. Kramer , Yasuyuki Arakane
Chitinases (CHT) comprise a large gene family in insects and have been classified into at least eleven subgroups. Many studies involving RNA interference (RNAi) have demonstrated that depletion of group I (CHT5s) and group II (CHT10s) CHT transcripts causes lethal molting arrest in several insect species including the red flour beetle, Tribolium castaneum, presumably due to failure of degradation of chitin in their old cuticle. In this study we investigated the functions of CHT5 and CHT10 in turnover of chitinous cuticle in T. castaneum during embryonic and post-embryonic molting stages. RNAi and transmission electron microscopic (TEM) analyses indicate that CHT10 is required for cuticular chitin degradation at each molting period analyzed, while CHT5 is essential for pupal-adult molting only. We further analyzed the functions of these genes during embryogenesis in T. castaneum. Real-time qPCR analysis revealed that peak expression of CHT10 occurred prior to that of CHT5 during embryonic development as has been observed at post-embryonic molting periods in several other insect species. With immunogold-labeling TEM analysis using a fluorescein isothiocyanate-conjugated chitin-binding domain protein (FITC-CBD) probe, chitin was detected in the serosal cuticle but not in any other regions of the eggshell including the chorion and vitelline membrane layers. Injection of double-stranded RNA (dsRNA) for CHT5 (dsCHT5), CHT10 (dsCHT10) or their co-injection (dsCHT5/10) into mature adult females had no effect on their fecundity and the resulting embryos developed normally inside the egg. There were no obvious differences in the morphology of the outer chorion, inner chorion and vitelline membrane among eggs from these dsRNA-treated females. However, unlike dsCHT5 eggs, dsCHT10 and dsCHT5/10 eggs exhibited failure of turnover of the serosal cuticle in which the horizontal chitinous laminae remained intact, resulting in lethal embryo hatching defects. These results indicate that group I CHT5 is essential for pupal-adult molting, whereas group II CHT10 plays an essential role in cuticular chitin degradation in T. castaneum during both embryonic hatching and all of the post-embryonic molts. CHT10 can serve in place of CHT5 in chitin degradation, except during the pupal-adult molt when both enzymes are indispensable to complete eclosion.
几丁质酶(CHT)是昆虫中一个庞大的基因家族,至少分为 11 个亚群。许多涉及 RNA 干扰(RNAi)的研究表明,在包括红粉甲虫(Tribolium castaneum)在内的一些昆虫物种中,第一组(CHT5s)和第二组(CHT10s)CHT 转录本的耗竭会导致蜕皮停止,这可能是由于其旧角质层中的几丁质降解失败所致。在这项研究中,我们研究了 CHT5 和 CHT10 在蓖麻金龟子胚胎和胚后蜕皮阶段几丁质角质层周转中的功能。RNAi 和透射电子显微镜(TEM)分析表明,CHT10 在所分析的每个蜕皮期都对角质层几丁质降解是必需的,而 CHT5 仅对蛹-成虫蜕皮是必需的。我们进一步分析了这些基因在 T. castaneum 胚胎发生过程中的功能。实时 qPCR 分析表明,在胚胎发育过程中,CHT10 的表达峰值先于 CHT5,这在其他几种昆虫的胚后蜕皮期也有观察到。通过使用异硫氰酸荧光素结合几丁质结合域蛋白(FITC-CBD)探针进行免疫金标记 TEM 分析,在血清角质层中检测到了几丁质,但在蛋壳的任何其他区域(包括绒毛膜和卵黄膜层)均未检测到几丁质。将 CHT5 和 CHT10 的双链 RNA(dsRNA)或它们的共同注射(dsCHT5/10)注入成熟的成年雌虫体内对其繁殖力没有影响,所产生的胚胎在卵内发育正常。经dsRNA处理的雌性卵子的外绒毛膜、内绒毛膜和卵黄膜形态没有明显差异。然而,与dsCHT5卵不同的是,dsCHT10和dsCHT5/10卵表现出浆膜角质层周转失败,其中水平壳质层保持完整,导致胚胎孵化缺陷致死。这些结果表明,第 I 组 CHT5 对蛹到成虫的蜕皮至关重要,而第 II 组 CHT10 则在 T. castaneum 胚胎孵化和胚胎后期的所有蜕皮过程中对角质层几丁质降解起着至关重要的作用。CHT10 可代替 CHT5 进行几丁质降解,但在蛹-成虫蜕皮过程中除外,因为这两种酶都是完成蜕皮不可或缺的。
{"title":"Functional importance of groups I and II chitinases, CHT5 and CHT10, in turnover of chitinous cuticle during embryo hatching and post-embryonic molting in the red flour beetle, Tribolium castaneum","authors":"Myeongjin Kim , Mi Young Noh , Seulgi Mun , Subbaratnam Muthukrishnan , Karl J. Kramer , Yasuyuki Arakane","doi":"10.1016/j.ibmb.2024.104087","DOIUrl":"10.1016/j.ibmb.2024.104087","url":null,"abstract":"<div><p><em>Chitinases</em> (<em>CHT</em>) comprise a large gene family in insects and have been classified into at least eleven subgroups. Many studies involving RNA interference (RNAi) have demonstrated that depletion of group I (CHT5s) and group II (CHT10s) <em>CHT</em> transcripts causes lethal molting arrest in several insect species including the red flour beetle, <em>Tribolium castaneum</em>, presumably due to failure of degradation of chitin in their old cuticle. In this study we investigated the functions of <em>CHT5</em> and <em>CHT10</em> in turnover of chitinous cuticle in <em>T. castaneum</em> during embryonic and post-embryonic molting stages. RNAi and transmission electron microscopic (TEM) analyses indicate that CHT10 is required for cuticular chitin degradation at each molting period analyzed, while CHT5 is essential for pupal-adult molting only. We further analyzed the functions of these genes during embryogenesis in <em>T. castaneum</em>. Real-time qPCR analysis revealed that peak expression of <em>CHT10</em> occurred prior to that of <em>CHT5</em> during embryonic development as has been observed at post-embryonic molting periods in several other insect species. With immunogold-labeling TEM analysis using a fluorescein isothiocyanate-conjugated chitin-binding domain protein (FITC-CBD) probe, chitin was detected in the serosal cuticle but not in any other regions of the eggshell including the chorion and vitelline membrane layers. Injection of double-stranded RNA (dsRNA) for <em>CHT5</em> (ds<em>CHT5</em>), <em>CHT10</em> (ds<em>CHT10</em>) or their co-injection (ds<em>CHT5/10</em>) into mature adult females had no effect on their fecundity and the resulting embryos developed normally inside the egg. There were no obvious differences in the morphology of the outer chorion, inner chorion and vitelline membrane among eggs from these dsRNA-treated females. However, unlike ds<em>CHT5</em> eggs, ds<em>CHT10</em> and ds<em>CHT5/10</em> eggs exhibited failure of turnover of the serosal cuticle in which the horizontal chitinous laminae remained intact, resulting in lethal embryo hatching defects. These results indicate that group I CHT5 is essential for pupal-adult molting, whereas group II CHT10 plays an essential role in cuticular chitin degradation in <em>T. castaneum</em> during both embryonic hatching and all of the post-embryonic molts. CHT10 can serve in place of CHT5 in chitin degradation, except during the pupal-adult molt when both enzymes are indispensable to complete eclosion.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139649039","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}
Pub Date : 2024-01-29DOI: 10.1016/j.ibmb.2024.104086
Masaya Ono , Takashi Matsumura , Eui Jae Sung , Takashi Koyama , Masanori Ochiai , Stephen B. Shears , Yoichi Hayakawa
Growth-blocking peptide (GBP), an insect cytokine, was first found in armyworm Mythimna separata. A functional analogue of GBP, stress-responsive peptide (SRP), was also identified in the same species. SRP gene expression has been demonstrated to be enhanced by GBP, indicating that both cytokines are organized within a hierarchical regulatory network. Although GBP1 (CG15917) and GBP2 (CG11395) have been identified in Drosophila melanogaster, immunological functions have only been characterized for GBP1. It is expected that the biological responses of two structurally similar peptides should be coordinated, but there is little information on this topic. Here, we demonstrate that GBP2 replicates the GBP1-mediated cellular immune response from Drosophila S2 cells. Moreover, the GBP2-induced response was silenced by pre-treatment with dsRNA targeting the GBP receptor gene, Mthl10. Furthermore, treatment of S2 cells with GBP2 enhanced GBP1 expression levels, but GBP1 did not affect GBP2 expression. GBP2 derived enhancement of GBP1 expression was not observed in the presence of GBP1, indicating that GBP2 is an upstream expressional regulator of a GBP1/GBP2 cytokine network. GBP2-induced enhancement of GBP1 expression was not observed in Mthl10 knockdown cells. Enhancement of GBP2 expression was observed in both Drosophila larvae and S2 cells under heat stress conditions; expressional enhancement of both GBP1 and GBP2 was eliminated in Mthl10 knockdown cells and larvae. Finally, Ca2+ mobilization assay in GCaMP3-expressing S2 cells demonstrated that GBP2 mobilizes Ca2+ upstream of Mthl10. Our finding revealed that Drosophila GBP1 and GBP2 control immune responses as well as their own expression levels through a hierarchical cytokine network, indicating that Drosophila GBP1/GBP2 system can be a simple model that is useful to investigate the detailed regulatory mechanism of related cytokine complexes.
{"title":"Drosophila cytokine GBP2 exerts immune responses and regulates GBP1 expression through GPCR receptor Mthl10","authors":"Masaya Ono , Takashi Matsumura , Eui Jae Sung , Takashi Koyama , Masanori Ochiai , Stephen B. Shears , Yoichi Hayakawa","doi":"10.1016/j.ibmb.2024.104086","DOIUrl":"10.1016/j.ibmb.2024.104086","url":null,"abstract":"<div><p>Growth-blocking peptide (GBP), an insect cytokine, was first found in armyworm <em>Mythimna separata</em>. A functional analogue of GBP, stress-responsive peptide (SRP), was also identified in the same species. SRP gene expression has been demonstrated to be enhanced by GBP, indicating that both cytokines are organized within a hierarchical regulatory network. Although GBP1 (CG15917) and GBP2 (CG11395) have been identified in <em>Drosophila melanogaster</em>, immunological functions have only been characterized for GBP1. It is expected that the biological responses of two structurally similar peptides should be coordinated, but there is little information on this topic. Here, we demonstrate that GBP2 replicates the GBP1-mediated cellular immune response from <em>Drosophila</em> S2 cells. Moreover, the GBP2-induced response was silenced by pre-treatment with dsRNA targeting the GBP receptor gene, <em>Mthl10</em>. Furthermore, treatment of S2 cells with GBP2 enhanced <em>GBP1</em> expression levels, but GBP1 did not affect <em>GBP2</em> expression. GBP2 derived enhancement of <em>GBP1</em> expression was not observed in the presence of GBP1, indicating that GBP2 is an upstream expressional regulator of a GBP1/GBP2 cytokine network. GBP2-induced enhancement of <em>GBP1</em> expression was not observed in <em>Mthl10</em> knockdown cells. Enhancement of <em>GBP2</em> expression was observed in both <em>Drosophila</em> larvae and S2 cells under heat stress conditions; expressional enhancement of both <em>GBP1</em> and <em>GBP2</em> was eliminated in <em>Mthl10</em> knockdown cells and larvae. Finally, Ca<sup>2+</sup> mobilization assay in GCaMP3-expressing S2 cells demonstrated that GBP2 mobilizes Ca<sup>2+</sup> upstream of Mthl10. Our finding revealed that <em>Drosophila</em> GBP1 and GBP2 control immune responses as well as their own expression levels through a hierarchical cytokine network, indicating that <em>Drosophila</em> GBP1/GBP2 system can be a simple model that is useful to investigate the detailed regulatory mechanism of related cytokine complexes.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139590144","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}
Pub Date : 2024-01-24DOI: 10.1016/j.ibmb.2024.104075
Linmeng Tang , Dongbin Chen , Dehong Yang , Zhiwei Liu , Xu Yang , Yujia Liu , Liying Zhang , Zulian Liu , Yaohui Wang , Zheng Tang , Yongping Huang
Uric acid is the end-product of nitrogen metabolism of the silkworm and other lepidopterans. The accumulation of uric acid particles in the epidermis causes the larval silkworm to appear white and opaque. However, the mechanism of uric acid granule formation is still unclear. Silkworm epidermis color is linked to the genes responsible for uric acid particle formation. We first identified two genes in the Bombyx mori genome that encode subunits of the Bloc-1 (Biogenesis of Lysosome-related Organelles Complex-1) by homology to these genes in other eukaryotes, Bmpali and Bmb1. Mutation in these genes caused a transparent phenotype in the silkworm larvae, and the loss of BmBloc-1 subunit gene Bmcap resulted in the same phenotype. These three genes are highly conserved between human and silkworm. We discovered that Bmpali, Bmcap, and Bmb1 localize in the cytoplasm of BmN cells. Yeast two-hybrid assays demonstrated that the Bmpali physically interacts with both Bmcap and Bmb1. Investigating the roles of Bmpali, Bmb1, and Bmcap is essential for uric acid granule formation understanding in Bombyx mori. These mutants present a valuable silkworm model for studying the biogenesis of lysosome-related organelles (LROs).
{"title":"Bmpali, Bmb1 and Bmcap are necessary for uric acid granule formation in Bombyx mori","authors":"Linmeng Tang , Dongbin Chen , Dehong Yang , Zhiwei Liu , Xu Yang , Yujia Liu , Liying Zhang , Zulian Liu , Yaohui Wang , Zheng Tang , Yongping Huang","doi":"10.1016/j.ibmb.2024.104075","DOIUrl":"10.1016/j.ibmb.2024.104075","url":null,"abstract":"<div><p>Uric acid is the end-product of nitrogen metabolism of the silkworm and other lepidopterans. The accumulation of uric acid particles in the epidermis causes the larval silkworm to appear white and opaque. However, the mechanism of uric acid granule formation is still unclear. Silkworm epidermis color is linked to the genes responsible for uric acid particle formation. We first identified two genes in the <em>Bombyx mori</em> genome that encode subunits of the Bloc-1 (Biogenesis of Lysosome-related Organelles Complex-1) by homology to these genes in other eukaryotes, <em>Bmpali</em> and <em>Bmb1</em>. Mutation in these genes caused a transparent phenotype in the silkworm larvae, and the loss of BmBloc-1 subunit gene <em>Bmcap</em> resulted in the same phenotype. These three genes are highly conserved between human and silkworm. We discovered that <em>Bmpali</em>, <em>Bmcap</em>, and <em>Bmb1</em> localize in the cytoplasm of BmN cells. Yeast two-hybrid assays demonstrated that the Bmpali physically interacts with both Bmcap and Bmb1. Investigating the roles of <em>Bmpali</em>, <em>Bmb1</em>, and <em>Bmcap</em> is essential for uric acid granule formation understanding in <em>Bombyx mori</em>. These mutants present a valuable silkworm model for studying the biogenesis of lysosome-related organelles (LROs).</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139566470","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}
Pub Date : 2024-01-14DOI: 10.1016/j.ibmb.2024.104074
Dacotah Melicher , Alex S. Torson , George D. Yocum , Jordi Bosch , William P. Kemp , Julia H. Bowsher , Joseph P. Rinehart
The solitary bee Osmia lignaria is a native pollinator in North America with growing economic importance. The life cycle of O. lignaria provides a unique opportunity to compare the physiological and molecular mechanisms underlying two ecologically contrasting dormancies within the same species. O. lignaria prepupae become dormant during the summer to avoid high temperatures. Shortly after adult eclosion, they enter a second dormancy and overwinter as diapausing adults. To compare these two dormancies, we measured metabolic rates and gene expression across development as bees initiate, maintain, and terminate both prepupal (summer) and adult (overwintering) dormancies. We observed a moderate temperature-independent decrease in gas exchange during both the prepupal dormancy after cocoon spinning (45 %) and during adult diapause after eclosion (60 %). We sequenced and assembled a high-quality reference genome from a single haploid male bee with a contiguous n50 of 5.5 Mbp to facilitate our transcriptomic analysis. The transcriptomes of dormant prepupae and diapausing adults clustered into distinct groups more closely associated with life stage than dormancy status. Membrane transport, membrane-bound cellular components, oxidoreductase activity, glutathione metabolism, and transcription factor activity increased during adult diapause, relative to prepupal dormancy. Further, the transcriptomes of adults in diapause clustered into two groups, supporting multiple phases of diapause during winter. Late adult diapause was associated with gene expression profiles supporting increased insulin/IGF, juvenile hormone, and ecdysone signaling.
{"title":"Metabolic and transcriptomic characterization of summer and winter dormancy in the solitary bee, Osmia lignaria","authors":"Dacotah Melicher , Alex S. Torson , George D. Yocum , Jordi Bosch , William P. Kemp , Julia H. Bowsher , Joseph P. Rinehart","doi":"10.1016/j.ibmb.2024.104074","DOIUrl":"10.1016/j.ibmb.2024.104074","url":null,"abstract":"<div><p>The solitary bee <em>Osmia lignaria</em> is a native pollinator in North America with growing economic importance. The life cycle of <em>O. lignaria</em> provides a unique opportunity to compare the physiological and molecular mechanisms underlying two ecologically contrasting dormancies within the same species. <em>O. lignaria</em> prepupae become dormant during the summer to avoid high temperatures. Shortly after adult eclosion, they enter a second dormancy and overwinter as diapausing adults. To compare these two dormancies, we measured metabolic rates and gene expression across development as bees initiate, maintain, and terminate both prepupal (summer) and adult (overwintering) dormancies. We observed a moderate temperature-independent decrease in gas exchange during both the prepupal dormancy after cocoon spinning (45 %) and during adult diapause after eclosion (60 %). We sequenced and assembled a high-quality reference genome from a single haploid male bee with a contiguous n50 of 5.5 Mbp to facilitate our transcriptomic analysis. The transcriptomes of dormant prepupae and diapausing adults clustered into distinct groups more closely associated with life stage than dormancy status. Membrane transport, membrane-bound cellular components, oxidoreductase activity, glutathione metabolism, and transcription factor activity increased during adult diapause, relative to prepupal dormancy. Further, the transcriptomes of adults in diapause clustered into two groups, supporting multiple phases of diapause during winter. Late adult diapause was associated with gene expression profiles supporting increased insulin/IGF, juvenile hormone, and ecdysone signaling.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0965174824000055/pdfft?md5=f9a7801d49b0e6ce8208b8eb94f0e4c3&pid=1-s2.0-S0965174824000055-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139469290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-12DOI: 10.1016/j.ibmb.2023.104069
Olga Frunze, Dain Lee, Seungha Lee, Hyung Wook Kwon
The host-seeking behavior of mosquitoes have long been established to be primarily odor-mediated. In this process, olfactory receptors (Ors) play a critical role. 1-Octen-3-ol is a common volatile compound that is attractive to hematophagous arthropods such as mosquitos. The olfactory receptor 8 (AaOr8) on the tip of the stylet and maxillary palp of Aedes aegypti is tuned to 1-octen-3-ol, which is required for mosquitoes to quickly find blood vessels from a vertebrate host. However, little is known about the interaction of AaOr8 with 1-octen-3-ol which was studied in vivo and in silico in this study. The molecular binding poses and energies between ligands and the receptor were investigated. Three mutants of AaOr8 were cloned and compared with in vivo calcium imaging utilizing heterologous expression systems. As a result, our findings imply that a genetic disruption including targeted modification of Ors genes may be used to reduce mosquito bites.
{"title":"A single mutation in the mosquito (Aedes aegypti) olfactory receptor 8 causes loss of function to 1-octen-3-ol","authors":"Olga Frunze, Dain Lee, Seungha Lee, Hyung Wook Kwon","doi":"10.1016/j.ibmb.2023.104069","DOIUrl":"10.1016/j.ibmb.2023.104069","url":null,"abstract":"<div><p>The host-seeking behavior of mosquitoes have long been established to be primarily odor-mediated. In this process, olfactory receptors (Ors) play a critical role. 1-Octen-3-ol is a common volatile compound that is attractive to hematophagous arthropods such as mosquitos. The olfactory receptor 8 (AaOr8) on the tip of the stylet and maxillary palp of <em>Aedes aegypti</em> is tuned to 1-octen-3-ol, which is required for mosquitoes to quickly find blood vessels from a vertebrate host. However, little is known about the interaction of AaOr8 with 1-octen-3-ol which was studied <em>in vivo</em> and <em>in silico</em> in this study. The molecular binding poses and energies between ligands and the receptor were investigated. Three mutants of AaOr8 were cloned and compared with <em>in vivo</em> calcium imaging utilizing heterologous expression systems. As a result, our findings imply that a genetic disruption including targeted modification of <em>Or</em>s genes may be used to reduce mosquito bites.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139465724","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}
Pub Date : 2024-01-11DOI: 10.1016/j.ibmb.2024.104073
Gözde Güney , Doga Cedden , Sabine Hänniger , Dwayne D. Hegedus , David G. Heckel , Umut Toprak
The peritrophic matrix (or peritrophic membrane, PM) is present in most insects where it acts as a barrier to mechanical insults and pathogens, as well as a facilitator of digestive processes. The PM is formed by the binding of structural PM proteins, referred to as peritrophins, to chitin fibrils and spans the entire midgut in lepidopterans. To investigate the role of peritrophins in a highly polyphagous lepidopteran pest, namely the cotton leafworm (Spodoptera littoralis), we generated Insect Intestinal Mucin (IIM−) and non-mucin Peritrophin (PER−) mutant strains via CRISPR/Cas9 mutagenesis. Both strains exhibited deformed PMs and retarded developmental rates. Bioassays conducted with Bacillus thuringiensis (Bt) and nucleopolyhedrovirus (SpliNPV) formulations showed that both the IIM− and PER− mutant larvae were more susceptible to these bioinsecticides compared to the wild-type (WT) larvae with intact PM. Interestingly, the provision of chitin-binding agent Calcofluor (CF) in the diet lowered the toxicity of Bt formulations in both WT and IIM− larvae and the protective effect of CF was significantly lower in PER− larvae. This suggested that the interaction of CF with PER is responsible for Bt resistance mediated by CF. In contrast, the provision of CF caused increased susceptibility to SpliNPV in both mutants and WT larvae. The study showed the importance of peritrophins in the defense against pathogens in S. littoralis and revealed novel insights into CF-mediated resistance to Cry toxin.
{"title":"Peritrophins are involved in the defense against Bacillus thuringiensis and nucleopolyhedrovirus formulations in Spodoptera littoralis (Lepidoptera: Noctuidae)","authors":"Gözde Güney , Doga Cedden , Sabine Hänniger , Dwayne D. Hegedus , David G. Heckel , Umut Toprak","doi":"10.1016/j.ibmb.2024.104073","DOIUrl":"10.1016/j.ibmb.2024.104073","url":null,"abstract":"<div><p><span><span><span>The peritrophic matrix (or peritrophic membrane, PM) is present in most insects where it acts as a barrier to mechanical insults and pathogens, as well as a facilitator of digestive processes. The PM is formed by the binding of structural </span>PM proteins<span>, referred to as peritrophins, to chitin fibrils and spans the entire midgut in </span></span>lepidopterans. To investigate the role of peritrophins in a highly polyphagous lepidopteran pest, namely the cotton leafworm (</span><span><em>Spodoptera littoralis</em></span>), we generated Insect Intestinal Mucin (IIM<sup>−</sup>) and non-mucin Peritrophin (PER<sup>−</sup><span>) mutant strains via CRISPR/Cas9 mutagenesis. Both strains exhibited deformed PMs and retarded developmental rates. Bioassays conducted with </span><span><em>Bacillus thuringiensis</em></span> (<em>Bt</em><span>) and nucleopolyhedrovirus (SpliNPV) formulations showed that both the IIM</span><sup>−</sup> and PER<sup>−</sup><span> mutant larvae were more susceptible to these bioinsecticides compared to the wild-type (WT) larvae with intact PM. Interestingly, the provision of chitin-binding agent Calcofluor (CF) in the diet lowered the toxicity of </span><em>Bt</em> formulations in both WT and IIM<sup>−</sup> larvae and the protective effect of CF was significantly lower in PER<sup>−</sup> larvae. This suggested that the interaction of CF with PER is responsible for <em>Bt</em> resistance mediated by CF. In contrast, the provision of CF caused increased susceptibility to SpliNPV in both mutants and WT larvae. The study showed the importance of peritrophins in the defense against pathogens in <em>S. littoralis</em> and revealed novel insights into CF-mediated resistance to Cry toxin.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139423978","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}
Pub Date : 2024-01-05DOI: 10.1016/j.ibmb.2024.104072
Veronika Urbanová , Stephen Lu , Eliška Kalinová , Larissa Martins , Tereza Kozelková , Filip Dyčka , José M. Ribeiro , Ondřej Hajdušek , Jan Perner , Petr Kopáček
Ticks are blood-feeding arachnids that are known to transmit various pathogenic microorganisms to their hosts. During blood feeding, ticks activate their metabolism and immune system to efficiently utilise nutrients from the host's blood and complete the feeding process. In contrast to insects, in which the fat body is known to be a central organ that controls essential metabolic processes and immune defense mechanisms, the function of the fat body in tick physiology is still relatively unexplored. To fill this gap, we sought to uncover the repertoire of genes expressed in the fat body associated with trachea (FB/Tr) by analyzing the transcriptome of individual, partially fed (previtellogenic) Ixodes ricinus females. The resulting catalog of individual mRNA sequences reveals a broad repertoire of transcripts encoding proteins involved in nutrient storage and distribution, as well as components of the tick immune system. To gain a detailed insight into the secretory products of FB/Tr specifically involved in inter-tissue transport and humoral immunity, the transcriptomic data were complemented with the proteome of soluble proteins in the hemolymph of partially fed female ticks. Among these proteins, the hemolipoglyco-carrier proteins were predominant. When comparing immune peptides and proteins from the fat body with those produced by hemocytes, we found that the fat body serves as a unique producer of certain immune components. Finally, time-resolved transcriptional regulation of selected immune transcripts from the FB/Tr was examined in response to experimental challenges with model microbes and analyzed by RT-qPCR. Overall, our data show that the fat body of ticks, similar to insects, is an important metabolic tissue that also plays a remarkable role in immune defense against invading microbes. These findings improve our understanding of tick biology and its impact on the transmission of tick-borne pathogens.
{"title":"From the fat body to the hemolymph: Profiling tick immune and storage proteins through transcriptomics and proteomics","authors":"Veronika Urbanová , Stephen Lu , Eliška Kalinová , Larissa Martins , Tereza Kozelková , Filip Dyčka , José M. Ribeiro , Ondřej Hajdušek , Jan Perner , Petr Kopáček","doi":"10.1016/j.ibmb.2024.104072","DOIUrl":"10.1016/j.ibmb.2024.104072","url":null,"abstract":"<div><p><span>Ticks are blood-feeding arachnids that are known to transmit various pathogenic microorganisms to their hosts. During blood feeding, ticks activate their metabolism and immune system to efficiently utilise nutrients from the host's blood and complete the feeding process. In contrast to insects, in which the fat body is known to be a central organ that controls essential metabolic processes and immune defense mechanisms, the function of the fat body in tick physiology is still relatively unexplored. To fill this gap, we sought to uncover the repertoire of genes expressed in the fat body associated with trachea (FB/Tr) by analyzing the transcriptome of individual, partially fed (previtellogenic) </span><span><em>Ixodes ricinus</em></span><span><span><span> females. The resulting catalog of individual mRNA sequences<span> reveals a broad repertoire of transcripts encoding proteins involved in nutrient storage and distribution, as well as components of the tick immune system. To gain a detailed insight into the secretory products of FB/Tr specifically involved in inter-tissue transport and humoral immunity, the </span></span>transcriptomic data were complemented with the </span>proteome<span><span> of soluble proteins in the hemolymph of partially fed female ticks. Among these proteins, the hemolipoglyco-carrier proteins were predominant. When comparing immune peptides and proteins from the fat body with those produced by </span>hemocytes, we found that the fat body serves as a unique producer of certain immune components. Finally, time-resolved transcriptional regulation of selected immune transcripts from the FB/Tr was examined in response to experimental challenges with model microbes and analyzed by RT-qPCR. Overall, our data show that the fat body of ticks, similar to insects, is an important metabolic tissue that also plays a remarkable role in immune defense against invading microbes. These findings improve our understanding of tick biology and its impact on the transmission of tick-borne pathogens.</span></span></p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139104718","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}
Pub Date : 2024-01-05DOI: 10.1016/j.ibmb.2024.104071
Dhyeykumar Rabadiya, Matthias Behr
Chitin is one of the most prevalent biomaterials in the natural world. The chitin matrix formation and turnover involve several enzymes for chitin synthesis, maturation, and degradation. Sequencing of the Drosophila genome more than twenty years ago revealed that insect genomes contain a number of chitinases, but why insects need so many different chitinases was unclear. Here, we focus on insect GH18 family chitinases and discuss their participation in chitin matrix formation and degradation. We describe their variations in terms of temporal and spatial expression patterns, molecular function, and physiological consequences at chitinous cuticles. We further provide insight into the catalytic mechanisms by discussing chitinase protein domain structures, substrate binding, and enzymatic activities with respect to structural analysis of the enzymatic GH18 domain, substrate-binding cleft, and characteristic TIM-barrel structure.
甲壳素是自然界中最常见的生物材料之一。几丁质基质的形成和周转涉及几种酶,用于几丁质的合成、成熟和降解。二十多年前果蝇基因组测序发现,昆虫基因组中含有多种几丁质酶,但为什么昆虫需要这么多不同的几丁质酶却不清楚。在这里,我们重点研究了昆虫 GH18 家族几丁质酶,并讨论了它们参与几丁质基质形成和降解的情况。我们描述了它们在几丁质角质层的时空表达模式、分子功能和生理后果方面的变化。我们通过讨论几丁质酶蛋白结构域结构、底物结合和酶活性,对酶 GH18 结构域、底物结合裂隙和特征性 TIM 管结构进行了结构分析,从而进一步深入了解了几丁质酶的催化机理。
{"title":"The biology of insect chitinases and their roles at chitinous cuticles","authors":"Dhyeykumar Rabadiya, Matthias Behr","doi":"10.1016/j.ibmb.2024.104071","DOIUrl":"10.1016/j.ibmb.2024.104071","url":null,"abstract":"<div><p>Chitin is one of the most prevalent biomaterials in the natural world. The chitin matrix formation and turnover involve several enzymes for chitin synthesis, maturation, and degradation. Sequencing of the <em>Drosophila</em> genome more than twenty years ago revealed that insect genomes contain a number of chitinases, but why insects need so many different chitinases was unclear. Here, we focus on insect GH18 family chitinases and discuss their participation in chitin matrix formation and degradation. We describe their variations in terms of temporal and spatial expression patterns, molecular function, and physiological consequences at chitinous cuticles. We further provide insight into the catalytic mechanisms by discussing chitinase protein domain structures, substrate binding, and enzymatic activities with respect to structural analysis of the enzymatic GH18 domain, substrate-binding cleft, and characteristic TIM-barrel structure.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S096517482400002X/pdfft?md5=85d3fcfdac5bb345abb11133b0e1419e&pid=1-s2.0-S096517482400002X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139104675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}