Insect Biochemistry and Molecular Biology最新文献

{"title":"The Relish/miR-275/Dredd mediated negative feedback loop is crucial to restoring immune homeostasis of Drosophila Imd pathway","authors":"Wanwan Pan ,&nbsp;Xiaolong Yao ,&nbsp;Lu Lin,&nbsp;Xiaoqi Liu,&nbsp;Ping Jin,&nbsp;Fei Ma","doi":"10.1016/j.ibmb.2023.104013","DOIUrl":"10.1016/j.ibmb.2023.104013","url":null,"abstract":"<div><p>The NF-κB/Relish, as a core transcription factor of <em>Drosophila</em><span> immune deficiency (Imd) pathway, activates the transcriptions of antimicrobial peptides (AMPs) to combat gram-negative bacterial infections, but its role in regulating miRNA expression during immune response has less been reported. We here describe a negative feedback loop of Imd signaling mediated by Relish/miR-275/</span><em>Dredd</em> that controls <em>Drosophila</em><span> immune homeostasis after </span><em>Escherichia coli</em> (<em>E</em>. <em>coli</em>) infection. Our results demonstrate that Relish may directly activate the transcription of miR-275 via binding to its promoter in <em>vitro</em> and <em>vivo</em>, particularly miR-275 further inhibits the expression of <em>Dredd</em> through binding to its 3′UTR to negatively control <em>Drosophila</em><span> Imd immune response. Remarkably, the ectopic expression of miR-275 significantly reduces </span><em>Drosophila</em> lifespan. More importantly, our work uncovers a new mechanism by which Relish can flexibly switch its role to maintain <em>Drosophila</em> immune response and homeostasis during infection. Collectively, our study not only reveals the functional duality of Relish in regulating immune response of <em>Drosophila</em> Imd pathway, but also provides a new insight into the maintenance of animal innate immune homeostasis.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"162 ","pages":"Article 104013"},"PeriodicalIF":3.8,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41101622","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 highly conserved plant volatile odorant receptor detects a sex pheromone component of the greater wax moth, Galleria mellonella (Lepidoptera: Pyralidae)","authors":"Paula Lizana ,&nbsp;Ricardo Godoy ,&nbsp;Francheska Martínez ,&nbsp;Dieter Wicher ,&nbsp;Sabine Kaltofen ,&nbsp;Leonardo Guzmán ,&nbsp;Oscar Ramírez ,&nbsp;Diego Cifuentes ,&nbsp;Ana Mutis ,&nbsp;Herbert Venthur","doi":"10.1016/j.ibmb.2023.104031","DOIUrl":"10.1016/j.ibmb.2023.104031","url":null,"abstract":"<div><p>Odorant receptors (ORs) are key specialized units for mate and host finding in moths of the Ditrysia clade, to which 98% of the lepidopteran species belong. Moth ORs have evolved to respond to long unsaturated acetates, alcohols, or aldehydes (Type I sex pheromones), falling into conserved clades of pheromone receptors (PRs). These PRs might have evolved from old lineages of non-Ditrysian moths that use plant volatile-like pheromones. However, a Ditrysian moth called the greater wax moth, <em>Galleria mellonella</em> (a worldwide-distributed pest of beehives), uses C₉–C₁₁ saturated aldehydes as the main sex pheromone components (i.e., nonanal and undecanal). Thus, these aldehydes represent unusual components compared with the majority of moth species that use, for instance, Type I sex pheromones. Current evidence shows a lack of consensus in the amount of ORs for <em>G. mellonella</em>, although consistent in that the moth does not have conserved PRs. Using genomic data, 62 OR candidates were identified, 16 being new genes. Phylogeny showed no presence of ORs in conserved PR clades. However, an OR with the highest transcript abundance, GmelOR4, appeared in a conserved plant volatile-detecting clade. Functional findings from the HEK system showed the OR as sensitive to nonanal and 2-phenylacetaldehyde, but not to undecanal. It is believed that to date GmelOR4 represents the first, but likely not unique, OR with a stable function in detecting aldehydes that help maintain the life cycle of <em>G. mellonella</em> around honey bee colonies.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"163 ","pages":"Article 104031"},"PeriodicalIF":3.8,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71419066","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":"Insulin-like peptides and ovary ecdysteroidogenic hormone differentially stimulate physiological processes regulating egg formation in the mosquito Aedes aegypti","authors":"Kangkang Chen ,&nbsp;Xiaoyi Dou ,&nbsp;Jai Hoon Eum,&nbsp;Ruby E. Harrison,&nbsp;Mark R. Brown,&nbsp;Michael R. Strand","doi":"10.1016/j.ibmb.2023.104028","DOIUrl":"10.1016/j.ibmb.2023.104028","url":null,"abstract":"<div><p>Mosquitoes including <em>Aedes aegypti</em> are human disease vectors because females must blood feed to produce and lay eggs. Blood feeding triggers insulin-insulin growth factor signaling (IIS) which regulates several physiological processes required for egg development. <em>A. aegypti</em> encodes 8 insulin-like peptides (ILPs) and one insulin-like receptor (IR) plus ovary ecdysteroidogenic hormone (OEH) that also activates IIS through the OEH receptor (OEHR). In this study, we assessed the expression of <em>A. aegypti</em> ILPs and OEH during a gonadotrophic cycle and produced each that were functionally characterized to further understand their roles in regulating egg formation. All <em>A. aegypti</em> ILPs and OEH were expressed during a gonadotrophic cycle. Five ILPs (1, 3, 4, 7, 8) and OEH were specifically expressed in the head, while antibodies to ILP3 and OEH indicated each was released after blood feeding from ventricular axons that terminate on the anterior midgut. A subset of ILP family members and OEH stimulated nutrient storage in previtellogenic females before blood feeding, whereas most IIS-dependent processes after blood feeding were activated by one or more of the brain-specific ILPs and/or OEH. ILPs and OEH with different biological activities also exhibited differences in IIS as measured by phosphorylation of the IR, phosphoinositide 3-kinase/Akt kinase (AKT) and mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK). Altogether, our results provide the first results that compare the functional activities of all ILP family members and OEH produced by an insect.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"163 ","pages":"Article 104028"},"PeriodicalIF":3.8,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71419068","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":"Dextran sulfate sodium and uracil induce inflammatory effects and disrupt the chitinous peritrophic matrix in the midgut of Tribolium castaneum","authors":"Anna Christina Böhringer ,&nbsp;Lara Deters ,&nbsp;Anton George Windfelder ,&nbsp;Hans Merzendorfer","doi":"10.1016/j.ibmb.2023.104029","DOIUrl":"10.1016/j.ibmb.2023.104029","url":null,"abstract":"<div><p>Dextran sulfate sodium is used in inflammatory bowel disease (IBD) mice models to trigger chronic intestinal inflammation. In this study, we have analyzed DSS effects in the genetic model and pest beetle, <em>Tribolium castaneum</em>, which can be easily and cost-effectively cultivated and examined in very large quantities compensating for individual variations. We fed the larvae with DSS and uracil, which is known to induce the production of reactive oxygen species by activating DUOX, a member of the NADPH oxidase family. Both chemicals induced IBD-like phenotypes, including impaired growth and development, midgut thickening, epithelial swelling, and a loss of epithelial barrier function. RNAi mediated knockdown of DUOX expression enhanced the effects of DSS and uracil on mortality. Finally, we showed that both treatments result in an altered activity of the intestinal microbiome, similar as observed in IBD patients. Our findings suggest that both chemicals impair the epithelial barrier by increasing the permeability of the peritrophic matrix. The loss of the barrier function may facilitate the entry of midgut bacteria triggering innate immune responses that also affect the intestinal microbiome. As the observed effects resemble those induced by DSS treatment in mice, <em>T. castaneum</em> might be suitable high-throughput invertebrate model for IBD research and preclinical studies.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"163 ","pages":"Article 104029"},"PeriodicalIF":3.8,"publicationDate":"2023-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0965174823001236/pdfft?md5=ec444c19e129bedab4943f7a4d65c787&pid=1-s2.0-S0965174823001236-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71419067","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}

{"title":"Mandibular glands secrete 24-methylenecholesterol into honey bee (Apis mellifera) food jelly","authors":"Anja Buttstedt ,&nbsp;Christian W.W. Pirk,&nbsp;Abdullahi A. Yusuf","doi":"10.1016/j.ibmb.2023.104011","DOIUrl":"10.1016/j.ibmb.2023.104011","url":null,"abstract":"<div><p>Honey bee (<em>Apis mellifera</em>) workers feed their larvae with food jelly that is secreted by specialized glands in their heads – the hypopharyngeal and the mandibular glands. Food jelly contains all the nutrients the larvae need to develop into adult honey bees, including essential dietary sterols. The main sterol in food jelly, 24-methylenecholesterol (24MC), is pollen-derived and delivered in food jelly to the larvae in a complex with two proteins, major royal jelly protein 1 (MRJP1) and apisim. Whereas the proteins are synthesized in the hypopharyngeal glands, the sterol-secreting gland has not been identified. We here identified the mandibular glands as sterol-secreting gland for food jelly production by direct detection of the four main honey bee sterols (24MC, campesterol, β-sitosterol and isofucosterol). Furthermore, 24MC seems to be specifically enriched in the mandibular glands, thereby ensuring that food jelly contains the amounts of 24MC necessary for complex formation with MRJP1 and apisimin.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"161 ","pages":"Article 104011"},"PeriodicalIF":3.8,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0965174823001054/pdfft?md5=7ed1a4cd75c387aa195cc2b0e37cf097&pid=1-s2.0-S0965174823001054-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10261762","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}

{"title":"Chemosensory proteins as putative semiochemical carriers in the desert isopod Hemilepistus reaumurii","authors":"Alessio Iannucci ,&nbsp;Jiao Zhu ,&nbsp;Livio Antonielli ,&nbsp;Anas Ayari ,&nbsp;Karima Nasri-Ammar ,&nbsp;Wolfgang Knoll ,&nbsp;Paolo Pelosi ,&nbsp;Francesca Romana Dani","doi":"10.1016/j.ibmb.2023.104012","DOIUrl":"https://doi.org/10.1016/j.ibmb.2023.104012","url":null,"abstract":"<div><p>The order Isopoda contains both aquatic and terrestrial species, among which <em>Hemilepistus reaumurii</em>, which lives in arid environments and is the most adapted to terrestrial life. Olfaction has been deeply investigated in insects while it has received very limited attention in other arthropods, particularly in terrestrial crustaceans. In insects, soluble proteins belonging to two main families, Odorant Binding Proteins (OBPs) and Chemosensory Proteins (CSPs), are contained in the olfactory sensillar lymph and are suggested to act as carriers of hydrophobic semiochemicals to or from membrane-bound olfactory receptors. Other protein families, namely Nieman-Pick type 2 (NPC2) and Lipocalins (LCNs) have been also reported as putative odorant carriers in insects and other arthropod clades. In this study, we have sequenced and analysed the transcriptomes of antennae and of the first pair of legs of <em>H</em>. <em>reaumurii</em> focusing on soluble olfactory proteins<em>.</em> Interestingly, we have found 13 genes encoding CSPs<em>,</em> whose sequences differ from those of the other arthropod clades, including non-isopod crustaceans, for the presence of two additional cysteine residues, besides the four conserved ones. Binding assays on two of these proteins showed strong affinities for fatty acids and long-chain unsaturated esters and aldehydes, putative semiochemicals for this species.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"162 ","pages":"Article 104012"},"PeriodicalIF":3.8,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41087238","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":"PEPCK and glucose metabolism homeostasis in arthropods","authors":"Renato Martins da Silva ,&nbsp;Carlos Renato de Oliveira Daumas Filho ,&nbsp;Christiano Calixto ,&nbsp;Jhenifer Nascimento da Silva ,&nbsp;Cintia Lopes ,&nbsp;Itabajara da Silva Vaz Jr ,&nbsp;Carlos Logullo","doi":"10.1016/j.ibmb.2023.103986","DOIUrl":"https://doi.org/10.1016/j.ibmb.2023.103986","url":null,"abstract":"<div><p>The fat body is responsible for a variety of functions related to energy metabolism in arthropods, by controlling the processes of <em>de novo</em><span><span> glucose production<span> (gluconeogenesis) and glycogen metabolism<span>. The rate-limiting factor of gluconeogenesis is the enzyme<span> phosphoenolpyruvate carboxykinase (PEPCK), generally considered to be the first committed step in this pathway. Although the study of PEPCK and gluconeogenesis has been for decades restricted to </span></span></span></span>mammalian models<span><span>, especially focusing on muscle and liver tissue, current research has demonstrated particularities about the regulation of this enzyme in arthropods, and described new functions. This review will focus on arthropod PEPCK, discuss different aspects to PEPCK regulation and function, its general role in the regulation of gluconeogenesis and other pathways. The text also presents our views on potentially important new directions for research involving this enzyme in a variety of metabolic adaptations (e.g. diapause), discussing enzyme isoforms, roles during arthropod </span>embryogenesis, as well as involvement in vector-pathogen interactions, contributing to a better understanding of insect vectors of diseases and their control.</span></span></p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"160 ","pages":"Article 103986"},"PeriodicalIF":3.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3036723","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":"Masculinizer gene controls male sex determination in the codling moth, Cydia pomonella","authors":"Kristýna Pospíšilová ,&nbsp;Arjen E. Van't Hof ,&nbsp;Atsuo Yoshido ,&nbsp;Renata Kružíková ,&nbsp;Sander Visser ,&nbsp;Magda Zrzavá ,&nbsp;Kseniya Bobryshava ,&nbsp;Martina Dalíková ,&nbsp;František Marec","doi":"10.1016/j.ibmb.2023.103991","DOIUrl":"https://doi.org/10.1016/j.ibmb.2023.103991","url":null,"abstract":"<div><p><span>The molecular mechanisms of sex determination in moths and butterflies<span> (Lepidoptera) with female heterogamety (WZ/ZZ) are poorly understood, except in the silkworm </span></span><span><em>Bombyx </em><em>mori</em></span>. However, the <em>Masculinizer</em> (<em>Masc</em><span>) gene that controls male development and dosage compensation in </span><em>B. mori</em><span>, appears to be conserved in Lepidoptera, as its masculinizing function was recently confirmed in several moth species. In this work, we investigated the role of the </span><em>Masc</em><span> gene in sex determination of the codling moth </span><em>Cydia pomonella</em><span> (Tortricidae), a globally important pest of pome fruits and walnuts. The gene structure of the </span><em>C. pomonella Masc</em> ortholog, <em>CpMasc</em>, is similar to <em>B. mori Masc</em>. However, unlike <em>B. mori</em>, we identified 14 splice variants of <em>CpMasc</em><span><span> in the available transcriptomes. Subsequent screening for sex specificity and </span>genetic variation using publicly available data and RT-PCR revealed three male-specific splice variants. Then qPCR analysis of these variants revealed sex-biased expression showing a peak only in early male embryos. Knockdown of </span><em>CpMasc</em><span> by RNAi<span> during early embryogenesis resulted in a shift from male-to female-specific splicing of the </span></span><span><em>C. pomonella </em><em>doublesex</em></span> (<em>Cpdsx</em>) gene, its downstream effector, in ZZ embryos, leading to a strongly female-biased sex ratio. These data clearly demonstrate that <em>CpMasc</em> functions as a masculinizing gene in the sex-determining cascade of <em>C. pomonella</em>. Our study also showed that <em>CpMasc</em><span> transcripts are provided maternally, as they were detected in unfertilized eggs after oviposition and in mature eggs dissected from virgin females. This finding is unique, as maternal provision of mRNA has rarely been studied in Lepidoptera.</span></p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"160 ","pages":"Article 103991"},"PeriodicalIF":3.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3034974","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 Wnt pathway regulates wing morph determination in Acyrthosiphon pisum","authors":"Ping Zhou,&nbsp;Xin Zong,&nbsp;Shuo Yan,&nbsp;Junzheng Zhang,&nbsp;Dan Wang,&nbsp;Jie Shen","doi":"10.1016/j.ibmb.2023.104003","DOIUrl":"https://doi.org/10.1016/j.ibmb.2023.104003","url":null,"abstract":"<div><p>Wing dimorphism occurs in insects as a survival strategy to adapt to environmental changes. In response to environmental cues, mother aphids transmit signals to their offspring, and the offspring either emerge as winged adults or develop as wingless adults with degeneration of the wing primordia in the early instar stage. However, how the wing morph is determined in the early instar stage is still unclear. Here, we established a surgical sampling method to obtain precise wing primordium tissues for transcriptome analysis. We identified Wnt as a regulator of wing determination in the early second instar stage in the pea aphid. Inhibiting Wnt signaling via knockdown of <em>Wnt2</em>, <em>Wnt11b</em>, the Wnt receptor-encoding gene <em>fz</em>2 or the downstream targets <em>vg</em> and <em>omb</em> resulted in a decreased proportion of winged aphids. Activation of Wnt signaling via knockdown of <em>miR-8</em>, an inhibitor of the Wnt/Wg pathway, led to an increased proportion of winged aphids. Furthermore, the wing primordia of wingless nymphs underwent apoptosis in the early second instar, and cell death was activated by knockdown of <em>fz2</em> under the wing-inducing condition. These results indicate that the developmental plasticity of aphid wings is modulated by the intrinsic Wnt pathway in response to environmental challenges.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"161 ","pages":"Article 104003"},"PeriodicalIF":3.8,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3035015","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":"Fibroin heavy chain gene replacement with a highly ordered synthetic repeat sequence in Bombyx mori","authors":"Yoko Takasu,&nbsp;Nobuto Yamada,&nbsp;Katsura Kojima,&nbsp;Masatoshi Iga,&nbsp;Fumiko Yukuhiro,&nbsp;Tetsuya Iizuka,&nbsp;Taiyo Yoshioka","doi":"10.1016/j.ibmb.2023.104002","DOIUrl":"https://doi.org/10.1016/j.ibmb.2023.104002","url":null,"abstract":"<div><p>The exceptional quality of silkworm silk is attributed to the amino acid sequence of its fibroin heavy chain (Fib-H) protein. The large central domain of Fib-H, which consists of glycine- and alanine-rich crystalline regions interspersed with amorphous motifs of approximately 30 amino acid residues, is considered crucial for fibrilization and determines the properties of the silk fiber. We established a technical platform to modify the <em>Fib-H</em> core region systematically using transcription activator-like effector nuclease-mediated homologous recombination through a somatic and germline gene knockin assay along with PCR-based screening. This efficient knockin system was used to generate a silkworm strain carrying a mutant <em>Fib-H</em> allele, in which the core region was replaced with a highly ordered synthetic repeat sequence of a length comparable with native <em>Fib-H</em> core. Heterozygous knockin mutants produced seemingly normal cocoons, whereas homozygotes did not and exhibited considerable degradation in their posterior silk glands (PSGs). Cross-sectional examination of the PSG lumen and tensile tests conducted on reeled silk threads indicated that the mutant Fib-H, which exhibited reduced stability in the PSG cells and lumen, affected the mechanical properties of the fiber. Thus, sequence manipulation of the Fib-H core domain was identified as a crucial step in successfully creating artificial silk using knockin technology.</p></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"161 ","pages":"Article 104002"},"PeriodicalIF":3.8,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3212816","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}