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1.
Pestic Biochem Physiol ; 202: 105934, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38879326

RESUMO

Syntaxin5 (Syx5) belongs to SNAREs family, which play important roles in fusion of vesicles to target membranes. Most of what we know about functions of Syx5 originates from studies in fungal or vertebrate cells, how Syx5 operates during the development of insects is poorly understood. In this study, we investigated the role of LmSyx5 in the gut development of the hemimetabolous insect Locusta migratoria. LmSyx5 was expressed in many tissues, with higher levels in the gut. Knockdown of LmSyx5 by RNA interference (RNAi) considerably suppressed feeding in both nymphs and adults. The dsLmSyx5-injected locusts lost body weight and finally died at a mortality of 100%. Furthermore, hematoxylin-eosin staining indicated that the midgut is deformed in dsLmSyx5-treated nymphs and the brush border in midgut epithelial cells is severely damaged, suggesting that LmSyx5 is involved in morphogenesis of the midgut. TEM further showed that the endoplasmic reticulum of midgut cells have a bloated appearance. Taken together, these results suggest that LmSyx5 is essential for midgut epithelial homeostsis that affects growth and development of L. migratoria. Thus, Syx5 is a promising RNAi target for controlling L. migratoria, and even other pests.


Assuntos
Comportamento Alimentar , Proteínas de Insetos , Mucosa Intestinal , Locusta migratoria , Proteínas Qa-SNARE , Locusta migratoria/genética , Locusta migratoria/crescimento & desenvolvimento , Locusta migratoria/metabolismo , Proteínas Qa-SNARE/genética , Proteínas Qa-SNARE/metabolismo , Mucosa Intestinal/crescimento & desenvolvimento , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Comportamento Alimentar/fisiologia , Técnicas de Silenciamento de Genes , Homologia de Sequência de Aminoácidos , Distribuição Tecidual , Peso Corporal/genética , Regulação da Expressão Gênica no Desenvolvimento
2.
Pestic Biochem Physiol ; 201: 105860, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38685214

RESUMO

The Osiris gene family is believed to play important roles in insect biology. Previous studies mainly focused on the roles of Osiris in Drorophila, how Osiris operates during the development of other species remains largely unknown. Here, we investigated the role of LmOsi17 in development of the hemimetabolous insect Locusta migratoria. LmOsi17 was highly expressed in the intestinal tract of nymphs. Knockdown of LmOsi17 by RNA interference (RNAi) in nymphs resulted in growth defects. The dsLmOsi17-injected nymphs did not increase in body weight or size and eventually died. Immunohistochemical analysis showed that LmOsi17 was localized to the epithelial cells of the foregut and the gastric caecum. Histological observation and hematoxylin-eosin staining indicate that the foregut and gastric caecum are deformed in dsLmOsi17 treated nymphs, suggesting that LmOsi17 is involved in morphogenesis of foregut and gastric caecum. In addition, we observed a significant reduction in the thickness of the new cuticle in dsLmOsi17-injected nymphs compared to control nymphs. Taken together, these results suggest that LmOsi17 contributes to morphogenesis of intestinal tract that affects growth and development of nymphs in locusts.


Assuntos
Proteínas de Insetos , Locusta migratoria , Morfogênese , Ninfa , Animais , Locusta migratoria/crescimento & desenvolvimento , Locusta migratoria/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Ninfa/crescimento & desenvolvimento , Interferência de RNA , Intestinos
3.
Int J Biol Macromol ; 266(Pt 2): 131137, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38537854

RESUMO

The coat protein II (COPII) complex consists of five primary soluble proteins, namely the small GTP-binding protein Sar1, the inner coat Sec23/Sec24 heterodimers, and the outer coat Sec13/Sec31 heterotetramers. COPII is essential for cellular protein and lipid trafficking through cargo sorting and vesicle formation at the endoplasmic reticulum. However, the roles of COPII assembly genes remain unknown in insects. In present study, we identified five COPII assembly genes (LmSar1, LmSec23, LmSec24, LmSec13 and LmSec31) in Locusta migratoria. RT-qPCR results revealed that these genes showed different expression patterns in multiple tissues and developmental days of fifth-instar nymphs. Injection of double-stranded RNA against each LmCOPII gene induced a high RNAi efficiency, and considerably suppressed feeding, and increased mortality to 100 %. Results from the micro-sectioning and hematoxylin-eosin staining of midguts showed that the brush border was severely damaged and the number of columnar cells was significantly reduced in dsLmCOPII-injected nymphs, as compared with the control. The dilated endoplasmic reticulum phenotype of columnar cells was observed by transmission electron microscopy. RT-qPCR results further indicated that silencing any of the five genes responsible for COPII complex assembly repressed the expression of genes involved in insulin/mTOR-associated nutritional pathway. Therefore, COPII assembly genes could be promising RNAi targets for insect pest management by disrupting gut and cuticle development.


Assuntos
Locusta migratoria , Interferência de RNA , Animais , Locusta migratoria/genética , Locusta migratoria/crescimento & desenvolvimento , Homeostase , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/genética , Trato Gastrointestinal/metabolismo
4.
PLoS Genet ; 17(1): e1009174, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33406121

RESUMO

Outbreaks of locust plagues result from the long-term accumulation of high-density egg production. The migratory locust, Locusta migratoria, displays dramatic differences in the egg-laid number with dependence on population density, while solitarious locusts lay more eggs compared to gregarious ones. However, the regulatory mechanism for the egg-laid number difference is unclear. Herein, we confirm that oosorption plays a crucial role in the regulation of egg number through the comparison of physiological and molecular biological profiles in gregarious and solitarious locusts. We find that gregarious oocytes display a 15% higher oosorption ratio than solitarious ones. Activinß (Actß) is the most highly upregulated gene in the gregarious terminal oocyte (GTO) compared to solitarious terminal oocyte (STO). Meanwhile, Actß increases sharply from the normal oocyte (N) to resorption body 1 (RB1) stage during oosorption. The knockdown of Actß significantly reduces the oosorption ratio by 13% in gregarious locusts, resulting in an increase in the egg-laid number. Based on bioinformatic prediction and experimental verification, microRNA-34 with three isoforms can target Actß. The microRNAs display higher expression levels in STO than those in GTO and contrasting expression patterns of Actß from the N to RB1 transition. Overexpression of each miR-34 isoform leads to decreased Actß levels and significantly reduces the oosorption ratio in gregarious locusts. In contrast, inhibition of the miR-34 isoforms results in increased Actß levels and eventually elevates the oosorption ratio of solitarious locusts. Our study reports an undescribed mechanism of oosorption through miRNA targeting of a TGFß ligand and provides new insights into the mechanism of density-dependent reproductive adaption in insects.


Assuntos
Locusta migratoria/genética , MicroRNAs/genética , Oócitos/crescimento & desenvolvimento , Reprodução/genética , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Locusta migratoria/crescimento & desenvolvimento , Oócitos/metabolismo , Densidade Demográfica
5.
Insect Sci ; 28(3): 705-717, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32401389

RESUMO

Wings are an important flight organ of insects and their morphogenesis depends on a series of cell-to-cell and cell-to-extracellular matrix interactions. Integrin as a transmembrane protein receptor mediates cell-to-cell adhesion, cell-to-extracellular matrix interactions and signal transduction. In the present study, we characterized an integrin gene that encodes integrinß-PS protein in Locusta migratoria. LmIntegrinß-PS is highly expressed in the wing pads and the middle stages of 5th instar nymphs. Immunohistochemical analysis revealed that the LmIntegrinß-PS protein was localized at the cell base of the two layers of wings. After suppression of LmIntegrinß-PS by RNA interference, the wing pads or wings were unable to form normally, with a blister wing appearance during nymph to nymph transition and nymph to adult transition. We further found that the dorsal and ventral epidermis of the wings after dsLmIntegrinß-PS injection were improperly connected and formed huge cavities revealed by hematoxylin and eosin staining. Furthermore, the morphology and structure of the wing cuticle was significantly disturbed which affected the stable arrangement and attachments of the wing epidermis. Moreover, the expression of related cell adhesion genes was significantly decreased in LmIntegrinß-PS-suppressed L. migratoria, suggesting that LmIntegrinß-PS is required for the morphogenesis and development of wings during molting by stabilizing cell adhesion and maintaining the cytoskeleton of these cells.


Assuntos
Integrinas , Locusta migratoria/crescimento & desenvolvimento , Muda/genética , Asas de Animais/crescimento & desenvolvimento , Animais , Adesão Celular , Citoesqueleto , Células Epidérmicas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Imuno-Histoquímica , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Integrinas/genética , Integrinas/metabolismo , Metamorfose Biológica , Morfogênese , Ninfa/crescimento & desenvolvimento , Interferência de RNA
6.
Insect Sci ; 28(2): 347-354, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32167220

RESUMO

Even though Paranosema locustae is widely used in China as a biological agent for controlling grasshoppers, the mortality rate is initially quite low. This study sought to determine whether the simultaneous use of P. locustae and Beauveria bassiana would be a more effective control strategy. Additionally, changes in the intestinal microbial communities of migratory locusts infected with the two pathogens were analyzed to investigate the roles of gut microbes in pathogen-host interactions. The mortality rate of locusts inoculated with B. bassiana and P. locustae simultaneously was not significantly higher than expected, but the mortality rates of locusts inoculated with B. bassiana 3, 6, and 9 days after inoculation with P. locustae were significantly higher than if their effects were additive, indicating synergism. A MiSeq analysis found that Weissella was the most common bacterium, representing 41.48% and 51.62% of the total bacteria in the mid- and hindguts, respectively, and the bacterial declines were greatest during dual infections with B. bassiana and P. locustae. The appropriately timed combined application of P. locustae and B. bassiana was more effective against locusts than either treatment alone. Moreover, the combined inoculation of the two pathogens changed the gut microflora of locusts, indicating the potential relevancy of their synergistic effects on locust control.


Assuntos
Beauveria/fisiologia , Microbioma Gastrointestinal , Locusta migratoria/microbiologia , Locusta migratoria/parasitologia , Microsporídios/fisiologia , Animais , China , Interações Hospedeiro-Patógeno , Locusta migratoria/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Ninfa/parasitologia
7.
Insect Mol Biol ; 29(6): 555-568, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32741000

RESUMO

Lipids of the insect cuticle have important roles in resistance against the arid environment and invasion of foreign substances. Fatty acid synthase (FAS) is an important enzyme of the insect lipid synthesis pathway. In the present study, we identified three FAS genes from transcriptome data of the migratory locust, Locusta migratoria, based on bioinformatics analyses. Among them, two FAS genes (LmFAS1 and LmFAS3) are highly expressed in the integument of fifth instar nymphs. Suppression of LmFAS1 and LmFAS3 by RNA interference caused lethality during ecdysis or shortly after moulting. The weight of the locusts and the content of lipid droplets were reduced compared with those of the control. The results of gas chromatography-mass spectrometry analysis showed that knockdown of LmFAS3 led to a decrease of both cuticular hydrocarbons and inner hydrocarbons (CHCs and IHCs) contents, especially the content of methyl branched hydrocarbons. By contrast, knockdown of LmFAS1 only resulted in a decrease in the IHC content, but not that of CHCs. By consequence, in LmFAS1- and LmFAS3-suppressed locusts, hydrocarbon deficiency reduced desiccation resistance and enhanced cuticle permeability and sensitivity to insecticides. These results indicate that LmFAS1 and LmFAS3 are essential for hydrocarbon production and cuticle permeability, which play influential roles in waterproofing the insect cuticle.


Assuntos
Exoesqueleto/fisiologia , Ácido Graxo Sintases/genética , Hidrocarbonetos/metabolismo , Proteínas de Insetos/genética , Locusta migratoria/fisiologia , Animais , Ácido Graxo Sintases/metabolismo , Proteínas de Insetos/metabolismo , Locusta migratoria/genética , Locusta migratoria/crescimento & desenvolvimento , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia
8.
Insect Biochem Mol Biol ; 123: 103404, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32428561

RESUMO

Mucins are highly glycosylated proteins that are characterized by a higher proportion of threonine, serine, and proline residues in their sequences. Although mucins in humans and vertebrates have been implicated in many biological processes, their roles in growth and development in invertebrates such as in insects remain largely unknown. Based on bioinformatic analyses, we identified eight mucin or mucin-like genes in the migratory locust, Locusta migratoria. RNA interference against these genes demonstrated that three Lmmucin genes were essential for the survival of L. migratoria nymphs, and one Lmmucin was required for adult wing development. Indeed, knockdown of Lmhemomucin and Lmmucin-12 caused lethal phenotypes, with an observed defect of the gastric caeca in which cells were detached from cell junctions. Deficiency of LmIIM3 resulted in lethality of nymphs, with defects of the peritrophic membrane in midgut. Suppression of Lmmucin-17 greatly impaired the structural integrity of the wing cuticle during nymph-adult molting. The present study revealed the significance of mucin and mucin-like genes in insect growth and development, using the orthopteran insect locust as a model.


Assuntos
Locusta migratoria , Mucinas , Animais , Quitina/metabolismo , Biologia Computacional/métodos , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Intestinos/embriologia , Locusta migratoria/embriologia , Locusta migratoria/genética , Locusta migratoria/crescimento & desenvolvimento , Muda/genética , Mucinas/genética , Mucinas/metabolismo , Ninfa/crescimento & desenvolvimento , Interferência de RNA , Asas de Animais/embriologia
9.
ACS Appl Mater Interfaces ; 12(23): 25581-25590, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32343541

RESUMO

The geometrical similarity of helicoidal fiber arrangement in many biological fibrous extracellular matrices, such as bone, plant cell wall, or arthropod cuticle, to that of cholesteric liquid mesophases has led to the hypothesis that they may form passively through a mesophase precursor rather than by direct cellular control. In search of direct evidence to support or refute this hypothesis, here, we studied the process of cuticle formation in the tibia of the migratory locust, Locusta migratoria, where daily growth layers arise by the deposition of fiber arrangements alternating between unidirectional and helicoidal structures. Using focused ion beam/scanning electron microscopy (FIB/SEM) volume imaging and scanning X-ray scattering, we show that the epidermal cells determine an initial fiber orientation, from which the final architecture emerges by the self-organized co-assembly of chitin and proteins. Fiber orientation in the locust cuticle is therefore determined by both active and passive processes.


Assuntos
Exoesqueleto/metabolismo , Quitina/metabolismo , Células Epidérmicas/metabolismo , Proteínas de Insetos/metabolismo , Locusta migratoria/crescimento & desenvolvimento , Exoesqueleto/ultraestrutura , Animais , Células Epidérmicas/ultraestrutura , Locusta migratoria/metabolismo , Aprendizado de Máquina , Microscopia Eletrônica de Varredura , Microvilosidades/metabolismo , Espalhamento de Radiação , Raios X
10.
J Insect Physiol ; 123: 104052, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32259526

RESUMO

Insect cuticular lipids are a complex cocktail of highly diverse cuticular hydrocarbons (CHCs), which form a hydrophobic surface coat to maintain water balance and to prevent desiccation and penetration of exogenous substances. Fatty acid elongases (ELOs) are key enzymes that participate in a common CHC synthesis pathway in insects. However, the importance of ELOs for CHC synthesis and function remains understudied. Using transcriptomic data, we have identified seven ELO genes (LmELO1-7) in the migratory locust Locusta migratoria. We determined their tissue-specific and temporal expression profiles in fifth instar nymphs. As we are interested in cuticle barrier formation, we performed RNA interference against LmELO7, which is mainly expressed in the integument. Suppression of LmELO7 significantly decreased its expression and caused lethality during or shortly after molting. CHC quantification by GC-MS analysis indicated that suppression of LmELO7 resulted in a decrease in total CHC amounts. By consequence, CHC deficiency reduced desiccation resistance and enhanced cuticle permeability in LmELO7-suppressed L. migratoria. Interestingly, LmELO7 expression is induced at low air humidity. Our results indicate that LmELO7 plays a vital role in the production of CHCs and, hence, cuticle permeability. Induction of LmELO7 expression in drought conditions suggests a key role of this gene in regulating desiccation resistance. This work is expected to help developing new strategies for insect pest management based on CHC function.


Assuntos
Exoesqueleto/fisiologia , Elongases de Ácidos Graxos/genética , Hidrocarbonetos/metabolismo , Proteínas de Insetos/genética , Locusta migratoria/fisiologia , Exoesqueleto/ultraestrutura , Animais , Elongases de Ácidos Graxos/metabolismo , Feminino , Proteínas de Insetos/metabolismo , Locusta migratoria/genética , Locusta migratoria/crescimento & desenvolvimento , Locusta migratoria/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Ninfa/ultraestrutura
11.
Gene ; 728: 144297, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31870788

RESUMO

DEAD-box (DDX) genes encode a group of RNA helicases that are highly conserved and ubiquitously expressed from prokaryotes to eukaryotes, and appear to participate in almost every aspect of RNA metabolism. Studies have been extensively done in yeast and human, in insect, beyond the flies, however, the information of these genes is limited. Here, we therefore identified and characterized 32 DDX genes from Locusta migratoria (L. migratoria), a crop pest. Overview of the gene structure and domain composition showed that the gene size varies significantly from one to fifteen exons, and the encoded proteins contain the conserved helicase core with various extensions at their amino and carboxyl termini. Phylogenetic trees informed that these locust DDX family members have orthologs in all insect species examined and can be classified into 30 subfamilies, all of them found counterparts in human, and most in yeast as well. Quantitative real-time PCR revealed that these genes are expressed in all stages and tissues examined, overall with higher expression level at second and third-instar nymphs and in the reproductive organs. RNA interference (RNAi) analyses showed that seven genes cause lethal phenotype when silenced, of which five lead to defective midgut and gastric caecum, indicating that these genes are essential for the survival and maintenance of normal digestive organs of locust. These data provide a foundation for further functional analysis of these DDX genes in locust.


Assuntos
RNA Helicases DEAD-box/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Locusta migratoria/genética , Interferência de RNA , Animais , RNA Helicases DEAD-box/antagonistas & inibidores , Evolução Molecular , Proteínas de Insetos/antagonistas & inibidores , Locusta migratoria/crescimento & desenvolvimento , Família Multigênica , Fenótipo , Filogenia
12.
Genomics ; 112(2): 1821-1828, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31669703

RESUMO

FMRFamide-related peptides (FaRPs) are a type of neuropeptide, which participate in a variety of physiological processes in insects. Previous study showed that myosuppressin, being a member of FaRPs, initiated pupal diapause in Mamestra brassicae. We presumed that FaRPs genes might play a critical role in photoperiodic diapause induction of L. migratoria. To verify our hypothesis, flrf, a precursor gene of FaRP from L. migratoria, was initially cloned under long and short photoperiods that encoded by flrf gene identified from central nervous system (CNS). Phylogenetic analysis showed that the protein encoded by L. migratoria flrf gene, clustered together with Nilaparvata lugens (Hemiptera: Delphacidae) with 100% bootstrap support, was basically an FMRFamide precursor homologue. We noticed the availability of -RFamide peptides (GSERNFLRFa, DRNFIRFa) under short photoperiod only, which suggested their functions related to photoperiodic diapause induction. RNAi and quantitative real-time PCR (qRT-PCR) results further confirmed that the flrf gene promoted locust's diapause.


Assuntos
Diapausa de Inseto , Proteínas de Insetos/genética , Locusta migratoria/genética , Oligopeptídeos/genética , Animais , Sistema Nervoso Central/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Proteínas de Insetos/metabolismo , Locusta migratoria/crescimento & desenvolvimento , Oligopeptídeos/metabolismo , Fotoperíodo , Espécies Reativas de Oxigênio/metabolismo
13.
Insect Biochem Mol Biol ; 116: 103281, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31740347

RESUMO

Arthropod EFLamide genes in chelicerates, myriapods, decapods and non pterygote hexapods encode various EFLamide paracopies on a single precursor. However, in more advanced insect species such multiple EFLamide paracopies encoding genes are absent. In some Hemiptera putative exons of an EFLamide gene coding for a single EFLamide have been identified, while in the migratory locust a similar exon could potentially code for two EFLamide peptides. The recent identification of an EFLGamide from Platynereis dumerilii as the ligand for an ortholog of the TRH GPCR, suggested that the arthropod EFLamides might similarly activate TRH GPCR orthologs. We here identify the TRH GPCR ortholog from Locusta migratoria and show that it is activated in nanomolar concentrations by the two EFLamides previously predicted from this species. We also show that in the central nervous system there seems to be only a single bilateral neuron in the protocerebrum expressing this peptide. Given this very limited expression of EFLamide in locusts, it is perhaps not surprising that this gene and its receptor have been lost in many other insect species. This shows again that although neuropeptides and their receptors may persist in different evoltionary lineages, their functions can change dramatically.


Assuntos
Proteínas de Insetos/genética , Locusta migratoria/genética , Neuropeptídeos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Feminino , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Locusta migratoria/crescimento & desenvolvimento , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Filogenia
14.
Insect Biochem Mol Biol ; 112: 103206, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31425850

RESUMO

Wings are an indispensable structure in many insects for their foraging, courtship, escape from predators, and migration. Cuticular proteins are major components of the insect cuticle and wings, but there is limited information on how cuticular proteins may play an essential role in wing morphogenesis. We identified a wing-specific cuticular protein, LmACP7, which belongs to the RR-2 subfamily of CPR chitin-binding proteins in the migratory locust. LmACP7 was initially produced in epidermal cells and subsequently migrated to the exocuticle at the pre-ecdysial stage in adult wings. Depletion of LmACP7 transcripts by RNA interference markedly reduced its protein amounts, which consequently led to abnormal wing morphogenesis. The deformed wings were curved, wrinkled, and failed to fully expand. We further demonstrated that the deformation was caused by both severe damage of the endocuticle and death of the epidermal cells in the wings. Based on these data, we propose that LmACP7 not only serves as an essential structural protein in the wing but is also required for the integrity of wing epithelial cells. LmACP7 contributes to production of the wing endocuticle and to the morphogenesis of functional wings in the migratory locust.


Assuntos
Proteínas de Insetos/genética , Locusta migratoria/genética , Asas de Animais/crescimento & desenvolvimento , Animais , Quitina/metabolismo , Células Epidérmicas/metabolismo , Proteínas de Insetos/metabolismo , Locusta migratoria/crescimento & desenvolvimento , Metamorfose Biológica/genética , Morfogênese/genética , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Interferência de RNA , Asas de Animais/anormalidades
15.
Insect Biochem Mol Biol ; 113: 103207, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31421206

RESUMO

The fat body is distributed throughout the body of insects, playing the essential role in intermediary metabolism and nutrient storage. However, the function of differentiation of fat bodies adhering to different tissues remains largely unknown. Here, we identified a fat body-like tissue (FLT) surrounding testis follicles and described its features at morphological, cellular and molecular levels. The FLT is morphologically distinguished with the abdominal fat body (FB) and dominated by diploid cells instead of polyploid cells. The transcriptomic analysis demonstrated that the FLT and FB have dramatically different gene expression profiles. Moreover, genes in the cell cycle pathway, which include both DNA replication- and cell division-related genes, were successively active during development of the FLT, suggesting that FLT cells possibly undergo a mitotic cycle rather than an endocycle. Deprivation of the FLT resulted in distortion of the testis follicles, disappearance of sperm bundles, reduction of total sperm number and increase of dead sperm, indicating a critical role of the FLT in the spermatogenesis in testis follicles. The special functional differentiation of the two similar tissues suggested that FLT-FB cells are able to establish a promising system to study mitotic-to-endocycle transition.


Assuntos
Corpo Adiposo/fisiologia , Locusta migratoria/fisiologia , Espermatogênese , Animais , Corpo Adiposo/crescimento & desenvolvimento , Locusta migratoria/crescimento & desenvolvimento , Masculino , Testículo/crescimento & desenvolvimento , Testículo/fisiologia
16.
Insect Biochem Mol Biol ; 113: 103210, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31422152

RESUMO

Insect cytochrome P450 monooxygenases (CYPs) play essential roles in both xenobiotic metabolism and developmental processes. However, the exact physiological function of many CYP genes remains largely unknown. Screening the expression of the CYP genes from the CYP2 and mitochondrial CYP clans of Drosophila melanogaster revealed that Cyp303a1 is highly expressed in the pupal stage. Knockdown of CYP303A1 transcripts by RNAi using the Gal4/UAS system with a ubiquitous driver (tubulin-Gal4) in Drosophila or by dsRNA injection in the last nymph stage of Locusta migratoria resulted in severe defects in eclosion and lethality during and after adult emergence. In Drosophila, tissue-specific RNAi of Cyp303a1 with a wing-specific driver (MS1096-Gal4) revealed that Cyp303a1 was essential for wing extension. Stage-specific RNAi of Cyp303a1 using Gal80ts for thermal-dependent-suppression found that the expression of Cyp303a1 at the middle pupal stage was absolutely required. Meanwhile, Cyp303a1 mutants exhibited more than 80% lethality at the late embryonic development stages. Embryonic lethality of the Cyp303a1 mutants was fully rescued by the ubiquitous overexpression of exogenous Cyp303a1. Taken together, we conclude that Cyp303a1 is indispensable for embryonic development and adult eclosion in D. melanogaster, the latter role being conserved over 400 million years of insect evolution.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Locusta migratoria/fisiologia , Muda/genética , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Locusta migratoria/genética , Locusta migratoria/crescimento & desenvolvimento , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Óvulo/crescimento & desenvolvimento , Óvulo/fisiologia , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/fisiologia
17.
Protein Cell ; 10(12): 883-901, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31292921

RESUMO

Phenotypic plasticity plays fundamental roles in successful adaptation of animals in response to environmental variations. Here, to reveal the transcriptome reprogramming in locust phase change, a typical phenotypic plasticity, we conducted a comprehensive analysis of multiple phase-related transcriptomic datasets of the migratory locust. We defined PhaseCore genes according to their contribution to phase differentiation by the adjustment for confounding principal components analysis algorithm (AC-PCA). Compared with other genes, PhaseCore genes predicted phase status with over 87.5% accuracy and displayed more unique gene attributes including the faster evolution rate, higher CpG content and higher specific expression level. Then, we identified 20 transcription factors (TFs) named PhaseCoreTF genes that are associated with the regulation of PhaseCore genes. Finally, we experimentally verified the regulatory roles of three representative TFs (Hr4, Hr46, and grh) in phase change by RNAi. Our findings revealed that core transcriptional signatures are involved in the global regulation of locust phase changes, suggesting a potential common mechanism underlying phenotypic plasticity in insects. The expression and network data are accessible in an online resource called LocustMine (http://www.locustmine.org:8080/locustmine).


Assuntos
Genes de Insetos , Estágios do Ciclo de Vida/genética , Locusta migratoria/crescimento & desenvolvimento , Locusta migratoria/genética , Animais , Conjuntos de Dados como Assunto , Expressão Gênica , Regulação da Expressão Gênica , Fatores de Transcrição/genética , Transcriptoma/genética
18.
Int J Mol Sci ; 20(8)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018489

RESUMO

Photoperiod is one of the most important maternal factors with an impact on the offspring diapause induction of Locusta migratoria. Previous studies have shown that forkhead box protein O (FOXO) plays an important role in regulating insect diapause, but how photoperiod stimulates maternal migratory locusts to regulate the next generation of egg diapause through the FOXO signaling pathway still needs to be addressed. In this study, the transcriptomes of ovaries and fat bodies of adult locusts under a long and short photoperiod were obtained. Among the total of 137 differentially expressed genes (DEGs) in both ovaries and fat bodies, 71 DEGs involved in FOXO signaling pathways might be closely related to diapause induction. 24 key DEGs were selected and their expression profiles were confirmed to be consistent with the transcriptome results using qRT-PCR. RNA interference was then performed to verify the function of retinoic acid induced protein gene (rai1) and foxo. Egg diapause rates were significantly increased by RNAi maternal locusts rai1 gene under short photoperiods. However, the egg diapause rates were significantly decreased by knock down of the foxo gene in the maternal locusts under a short photoperiod. In addition, reactive oxygen species (ROS) and superoxide dismutase (SOD) activities were promoted by RNAi rai1. We identified the candidate genes related to the FOXO pathway, and verified the diapause regulation function of rai1 and foxo under a short photoperiod only. In the future, the researchers can work in the area to explore other factors and genes that can promote diapause induction under a long photoperiod.


Assuntos
Diapausa de Inseto , Locusta migratoria/crescimento & desenvolvimento , Locusta migratoria/genética , Transcriptoma , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Fotoperíodo , Fatores de Transcrição/genética
19.
Insect Mol Biol ; 28(4): 537-549, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30719786

RESUMO

The nuclear receptor-mediated 20-hydroxyecdysone (20E) signalling pathway plays crucial roles in insects by initiating and regulating moulting and metamorphosis. In the present study, we identified and characterized a cDNA encoding a putative nuclear receptor protein (Locusta migratoria hormone receptor 39, LmHR39) based on L. migratoria transcriptomics data. Reverse-transcription quantitative PCR (RT-qPCR) revealed that LmHR39 shows low-level expression in the early days of fifth-instar nymphs, and peak expression occurs on day 5, which is followed by a decrease before ecdysis. LmHR39 transcription could be induced by 20E in vivo and was significantly suppressed by knocking down the expression of the L. migratoria ecdysone receptor gene and early-late gene LmHR3. After RNA interference of LmHR39 with double-stranded RNA (dsRNA), 85% of the insects showed abnormal morphology, with curly wings after moulting and delayed eclosion time. Haematoxylin and eosin staining indicated that apolysis of the integument and wing pad cuticle in the dsLmHR39-treated insects was delayed compared to that in the dsRNA for green fluorescent protein-injected control. Furthermore, RNA-sequencing and RT-qPCR analysis showed the expression level of carboxypeptidase genes (Carboxypeptidase A (CPA) and Carboxypeptidase M (CPM)) and chitin degrading genes (LmChitinase5 (LmCHT5) and LmChitinase10 (LmCHT10)) dramatically declined in the dsLmHR39-treated insects, implying that the LmHR39-mediated 20E signalling pathway is involved in the regulation of carboxypeptidase genes (CPA and CPM) and chitinase genes (LmCHT5 and LmCHT10), and participated in apolysis of the integument and wing pads during locust moulting.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Locusta migratoria/genética , Muda/genética , Receptores Citoplasmáticos e Nucleares/genética , Sequência de Aminoácidos , Animais , Carboxipeptidases/genética , Quitinases/genética , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Locusta migratoria/enzimologia , Locusta migratoria/crescimento & desenvolvimento , Locusta migratoria/metabolismo , Ninfa/enzimologia , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/metabolismo , Filogenia , Receptores Citoplasmáticos e Nucleares/química , Receptores Citoplasmáticos e Nucleares/metabolismo , Alinhamento de Sequência
20.
J Exp Biol ; 222(Pt 2)2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30446536

RESUMO

The effect of previous exposure to lateral sensory stimuli in shaping the response to subsequent symmetric stimuli represents an important overlooked issue in neuroethology, with special reference to arthropods. In this research, we investigated the hypothesis to 'programme' jumping escape direction as well as surveillance orientation in young and adult individuals of Locusta migratoria as an adaptive consequence of prior exposure to directional-biased predator approaches generated by a robotic leopard gecko representing Eublepharis macularius The manipulation of the jumping escape direction was successfully achieved in young locusts, although young L. migratoria did not exhibit innately lateralized jumping escapes. Jumping escape direction was also successfully manipulated in adult locusts, which exhibited innate lateralized jumping escape at the individual level. The innate lateralization of each instar of L. migratoria in using a preferential eye during surveillance was not affected by prior lateralized exposure to the robotic gecko. Our results indicate a high plasticity of the escape motor outputs that are occurring almost in real time with the perceived stimuli, making them greatly adaptable and compliant to environmental changes in order to be effective and reliable. In addition, surveillance lateralization innately occurs at population level in each instar of L. migratoria Therefore, its low forgeability by environmental factors would avoid disorganization at swarm level and improve swarm coordination during group tasks. These findings are consistent with the fact that, as in vertebrates, in insects the right hemisphere is specialized in controlling fear and escape functions.


Assuntos
Lateralidade Funcional/fisiologia , Locusta migratoria/fisiologia , Percepção Visual , Animais , Fenômenos Biomecânicos , Reação de Fuga , Locusta migratoria/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Robótica
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