scholarly journals Circadian regulation of night feeding and daytime detoxification in a formidable Asian pest Spodoptera litura

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jiwei Zhang ◽  
Shenglong Li ◽  
Wanshun Li ◽  
Zhiwei Chen ◽  
Huizhen Guo ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Cultured Cells ◽  
Clock Genes ◽  
Feedback System ◽  
Agricultural Pests ◽  
Night Feeding ◽  
Controlling Mechanism ◽  
E Boxes ◽  
Sirna Knockdown ◽  
Circadian Behavior

AbstractVoracious feeding, trans-continental migration and insecticide resistance make Spodoptera litura among the most difficult Asian agricultural pests to control. Larvae exhibit strong circadian behavior, feeding actively at night and hiding in soil during daytime. The daily pattern of larval metabolism was reversed, with higher transcription levels of genes for digestion (amylase, protease, lipase) and detoxification (CYP450s, GSTs, COEs) in daytime than at night. To investigate the control of these processes, we annotated nine essential clock genes and analyzed their transcription patterns, followed by functional analysis of their coupling using siRNA knockdown of interlocked negative feedback system core and repressor genes (SlituClk, SlituBmal1 and SlituCwo). Based on phase relationships and overexpression in cultured cells the controlling mechanism seems to involve direct coupling of the circadian processes to E-boxes in responding promoters. Additional manipulations involving exposure to the neonicotinoid imidacloprid suggested that insecticide application must be based on chronotoxicological considerations for optimal effectiveness.

scholarly journals DEC1 Modulates the Circadian Phase of Clock Gene Expression

2008 ◽  
Vol 28 (12) ◽  
pp. 4080-4092 ◽  
Author(s):  
Ayumu Nakashima ◽  
Takeshi Kawamoto ◽  
Kiyomasa K. Honda ◽  
Taichi Ueshima ◽  
Mitsuhide Noshiro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clock Genes ◽  
Luciferase Reporter ◽  
Constant Darkness ◽  
Mobility Shift ◽  
Behavioral Rhythms ◽  
Circadian Phase ◽  
Clock Gene Expression ◽  
E Box ◽  
E Boxes

ABSTRACT DEC1 suppresses CLOCK/BMAL1-enhanced promoter activity, but its role in the circadian system of mammals remains unclear. Here we examined the effect of Dec1 overexpression or deficiency on circadian gene expression triggered with 50% serum. Overexpression of Dec1 delayed the phase of clock genes such as Dec1, Dec2, Per1, and Dbp that contain E boxes in their regulatory regions, whereas it had little effect on the circadian phase of Per2 and Cry1 carrying CACGTT E′ boxes. In contrast, Dec1 deficiency advanced the phase of the E-box-containing clock genes but not that of the E′-box-containing clock genes. Accordingly, DEC1 showed strong binding and transrepression on the E box, but not on the E′ box, in chromatin immunoprecipitation, electrophoretic mobility shift, and luciferase reporter assays. Dec1 −/− mice showed behavioral rhythms with slightly but significantly longer circadian periods under conditions of constant darkness and faster reentrainment to a 6-h phase-advanced shift of a light-dark cycle. Knockdown of Dec2 with small interfering RNA advanced the phase of Dec1 and Dbp expression, and double knockdown of Dec1 and Dec2 had much stronger effects on the expression of the E-box-containing clock genes. These findings suggest that DEC1, along with DEC2, plays a role in the finer regulation and robustness of the molecular clock.

scholarly journals A proteolytic C-terminal fragment of Nogo-A (reticulon-4A) is released in exosomes and potently inhibits axon regeneration

2019 ◽  
Vol 295 (8) ◽  
pp. 2175-2183 ◽  
Author(s):  
Yuichi Sekine ◽  
Jane A. Lindborg ◽  
Stephen M. Strittmatter
Keyword(s):  
Spinal Cord ◽  
Axonal Regeneration ◽  
Axon Regeneration ◽  
Cultured Cells ◽  
Enzyme Inhibitor ◽  
Recombinant Protein Expression ◽  
Cord Injury ◽  
Central Nervous System Trauma ◽  
Associated Proteins ◽  
Sirna Knockdown

Glial signals are known to inhibit axonal regeneration and functional recovery after mammalian central nervous system trauma, including spinal cord injury. Such signals include membrane-associated proteins of the oligodendrocyte plasma membrane and astrocyte-derived, matrix-associated proteins. Here, using cell lines and primary cortical neuron cultures, recombinant protein expression, immunoprecipitation and immunoblot assays, transmission EM of exosomes, and axon regeneration assays, we explored the secretion and activity of the myelin-associated neurite outgrowth inhibitor Nogo-A and observed exosomal release of a 24-kDa C-terminal Nogo-A fragment from cultured cells. We found that the cleavage site in this 1192-amino-acid-long fragment is located between amino acids 961–971. We also detected a Nogo-66 receptor (NgR1)–interacting Nogo-66 domain on the exosome surface. Enzyme inhibitor treatment and siRNA knockdown revealed that β-secretase 1 (BACE1) is the protease responsible for Nogo-A cleavage. Functionally, exosomes with the Nogo-66 domain on their surface potently inhibited axonal regeneration of mechanically injured cerebral cortex neurons from mice. Production of this fragment was observed in the exosomal fraction from neuronal tissue lysates after spinal cord crush injury of mice. We also noted that, relative to the exosomal marker Alix, a Nogo-immunoreactive, 24-kDa protein is enriched in exosomes 2-fold after injury. We conclude that membrane-associated Nogo-A produced in oligodendrocytes is processed proteolytically by BACE1, is released via exosomes, and is a potent diffusible inhibitor of regenerative growth in NgR1-expressing axons.

scholarly journals Spliceosome factors target timeless (tim) mRNA to control clock protein accumulation and circadian behavior in Drosophila

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Iryna Shakhmantsir ◽  
Soumyashant Nayak ◽  
Gregory R Grant ◽  
Amita Sehgal
Keyword(s):  
Negative Feedback ◽  
Clock Genes ◽  
Editorial Note ◽  
Protein Accumulation ◽  
Small Nuclear Ribonucleoprotein ◽  
Clock Proteins ◽  
Alternatively Spliced ◽  
Active Transcription ◽  
Nuclear Ribonucleoprotein ◽  
Circadian Behavior

Transcription-translation feedback loops that comprise eukaryotic circadian clocks rely upon temporal delays that separate the phase of active transcription of clock genes, such as Drosophila period (per) and timeless (tim), from negative feedback by the two proteins. However, our understanding of the mechanisms involved is incomplete. Through an RNA interference screen, we found that pre-mRNA processing 4 (PRP4) kinase, a component of the U4/U5.U6 triple small nuclear ribonucleoprotein (tri-snRNP) spliceosome, and other tri-snRNP components regulate cycling of the molecular clock as well as rest:activity rhythms. Unbiased RNA-Sequencing uncovered an alternatively spliced intron in tim whose increased retention upon prp4 downregulation leads to decreased TIM levels. We demonstrate that the splicing of tim is rhythmic with a phase that parallels delayed accumulation of the protein in a 24 hr cycle. We propose that alternative splicing constitutes an important clock mechanism for delaying the daily accumulation of clock proteins, and thereby negative feedback by them.Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (<xref ref-type="decision-letter" rid="SA1">see decision letter</xref>).

scholarly journals Novel muscle-specific enhancer sequences upstream of the cardiac actin gene.

1994 ◽  
Vol 14 (5) ◽  
pp. 3504-3513 ◽  
Author(s):  
C Biben ◽  
B J Kirschbaum ◽  
I Garner ◽  
M Buckingham
Keyword(s):  
Cultured Cells ◽  
Proximal Promoter ◽  
Actin Gene ◽  
Mrna Levels ◽  
Distal Enhancer ◽  
Cardiac Actin ◽  
E Box ◽  
C3h Mice ◽  
Myogenic Factors ◽  
E Boxes

A DNase I-hypersensitive site analysis of the 5'-flanking region of the mouse alpha-cardiac actin gene with muscle cell lines derived from C3H mice shows the presence of two such sites, at about -5 and -7 kb. When tested for activity in cultured cells with homologous and heterologous promoters, both sequences act as muscle-specific enhancers. Transcription from the proximal promoter of the alpha-cardiac actin gene is increased 100-fold with either enhancer. The activity of the distal enhancer in C2/7 myotubes is confined to an 800-bp fragment, which contains multiple E boxes. In transfection assays, this sequence does not give detectable transactivation by any of the myogenic factors even though one of the E boxes is functionally important. Bandshift assays showed that MyoD and myogenin can bind to this E box. However, additional sequences are also required for activity. We conclude that in the case of this muscle enhancer, myogenic factors alone are not sufficient to activate transcription either directly via an E box or indirectly through activation of genes encoding other muscle factors. In BALB/c mice, in which cardiac actin mRNA levels are 8- to 10-fold lower, the alpha-cardiac actin locus is perturbed by a 9.5-kb insertion (I. Garner, A. J. Minty, S. Alonso, P. J. Barton, and M. E. Buckingham, EMBO J. 5:2559-2567, 1986). This is located at -6.5 kb, between the two enhancers. The insertion therefore distances the distal enhancer from the promoter and from the proximal enhancer of the bona fide cardiac actin gene, probably thus perturbing transcriptional activity.

Identification and dynamic expression profiling of circadian clock genes in Spodoptera litura provide new insights into the regulation of sex pheromone communication

2021 ◽  
pp. 1-13
Author(s):  
Ji-Wei Xu ◽  
Lu-Lu Li ◽  
Meng Wang ◽  
Hui-Hui Yang ◽  
Wei-Chen Yao ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Spodoptera Litura ◽  
Clock Genes ◽  
Sexual Communication ◽  
Expression Patterns ◽  
Rhythmic Activity ◽  
Economic Damage ◽  
Rhythmic Expression ◽  
A Genome ◽  
Circadian Clock Genes

Abstract Spodoptera litura is an important pest that causes significant economic damage to numerous crops worldwide. Sex pheromones (SPs) mediate sexual communication in S. litura and show a characteristic degree of rhythmic activity, occurring mainly during the scotophase; however, the specific regulatory mechanisms remain unclear. Here, we employed a genome-wide analysis to identify eight candidate circadian clock genes in S. litura. Sequence characteristics and expression patterns were analyzed. Our results demonstrated that some circadian clock genes might regulate the biosynthesis and perception of SPs by regulating the rhythmic expression of SP biosynthesis-related genes and SP perception-related genes. Interestingly, all potential genes exhibited peak expression in the scotophase, consistent with the SP could mediate courtship and mating behavior in S. litura. Our findings are helpful in elucidating the molecular mechanism by which circadian clock genes regulate sexual communication in S. litura.

scholarly journals BAKTERI ENTOMOPATOGEN SEBAGAI AGEN BIOKONTROL TERHADAP LARVA Spodoptera litura (F.)

2017 ◽  
Vol 16 (1) ◽  
pp. 13-21
Author(s):  
Deni Zulfiana ◽  
Ni Putu Ratna Ayu Krishanti ◽  
Bramantyo Wikantyoso ◽  
Apriwi Zulfitri
Keyword(s):  
Bacillus Thuringiensis ◽  
Spodoptera Litura ◽  
Biocontrol Agent ◽  
Insect Control ◽  
Agricultural Pests ◽  
The Third ◽  
Entomopathogenic Bacteria ◽  
Almost All ◽  
Lepidoptera Noctuidae ◽  
Third Instar Larvae

Spodoptera litura (F.) (Lepidoptera: Noctuidae) is one of the agricultural pests that attacking almost all kinds of herbaceous plants, especiallyvegetables. Insect control using entomopathogenic bacteria is an alternative strategy that is effective and has a lower environmental impact than the use of synthetic insecticides. The purpose of this research was to explore entomopathogenic bacteria that have insecticidal activity against S. litura larvae at various stages of instars. The result showed that 25% of total number of isolated bacteria have potency as entomopathogenic bacteria. Isolate Staphylococcus sciuri strain BLSP-3 and isolate Serratia sp. strain BLSP-4 showed the highest larvicidal activity against the first and second instar larvae of S. litura 83% and 86%, respectively. The activity against on the third instar larvae however was only by 40%. However, the mortality caused by both isolates was lower than that of Bacillus thuringiensis (more than 90% mortality to the first and second instars and 80 % of the third instar larvae). It is suggested that both of isolates are potential to be developed further as a biocontrol agent to control S. litura population.

scholarly journals Identification and functional analysis of diet-responsive genes in Spodoptera litura (Fabricius)

2020 ◽  
Author(s):  
Li Wang ◽  
Peng Zhao ◽  
Junyu Luo ◽  
Chunyi Wang ◽  
Xiangzhen Zhu ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Host Plants ◽  
Glutathione Metabolism ◽  
Larval Performance ◽  
Rna Seq ◽  
Agricultural Pests ◽  
Plant Host ◽  
Wide Range ◽  
Plant Hosts ◽  
Bioassay Data

Abstract Background: Spodoptera litura is one of the most devastating agricultural pests with a wide range of host plants. To study larval performance on different diets and midgut adaptation at transcriptional levels, feeding assay and RNA-Seq experiments were conducted. RNA interference technology was used to explore the detoxification and metabolism of two cytochrome P450 genes. Results: The bioassay data showed that Spodoptera litura larvae developed more quickly when fed on cabbage than when fed on soybean, corn and cotton, tannin can inhibit the growth of Spodoptera litura. The result of RNA-Seq indicated that Spodoptera litura midgut modified gene expression levels to accommodate different diets, and the most differentially expressed genes were detoxification-related and digestion-related genes. Further analysis showed that the glutathione metabolism pathway was the common detoxification pathway in Spodoptera litura. The expression of cytochrome P450 genes showed a clear response to different plant hosts, and these differences may play key functions in primary detoxification of secondary metabolites from host plants. Meanwhile, the digestive enzymes of proteinases, lipases, and carbohydrases in midgut showed special responses to different plant hosts. After injection of dsRNA of CYP321A19 and CYP6AB60, the expression level of target gene were decreased, and the sensitivity of insect to plant allelochemicals increased and the weight increase significantly slowed. Conclusion: In this study, genes involved in detoxification were identified, and the results demonstrate the genes and pathways Spodoptera litura utlize to detoxify specific plant-host allelochemicals. These results may also provide a theoretical basis for Spodoptera litura management.

scholarly journals Transcriptomic analysis of the testicular fusion in Spodoptera litura

2019 ◽  
Author(s):  
Lin Liu ◽  
Yaqing Chen ◽  
Jun Ou ◽  
Yucheng Liu ◽  
Qiong Wu ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Critical Role ◽  
Gonad Development ◽  
Signal Transduction Pathway ◽  
Rna Seq ◽  
Agricultural Pests ◽  
Ecm Remodeling ◽  
Plant Feeding ◽  
The Matrix ◽  
Ecm Degradation

Abstract Background Lepidoptera is one group of the largest plant-feeding insects and Spodoptera litura (Lepidoptera: Noctuidae) is one of the most serious agricultural pests in Asia countries. An interesting and unique phenomenon for gonad development of Lepidoptera is the testicular fusion. Two separated testes fused into a single one during the larva-to-pupa metamorphosis, which is believed to contribute to sperm production and the prevalence in field. To study the molecular mechanism of the testicular fusion, RNA sequencing (RNA-seq) experiments of the testes from 4-day-old sixth instar larvae (L6D4) (before fusion), 6-day-old sixth instar larvae (L6D6, prepupae) (on fusing) and 4-day-old pupae (P4D) (after fusion) of S. litura were performed.Results RNA-seq data of the testes showed that totally 12,339 transcripts were expressed at L6D4, L6D6 and P4D stages. A large number of differentially expressed genes (DEGs) were up-regulated from L6D4 to L6D6, and then more genes were down-regulated from L6D6 to P4D. The DEGs mainly belongs to the genes related to the 20E signal transduction pathway, transcription factors, chitin metabolism related enzymes, the families of cytoskeleton proteins, extracellular matrix (ECM) components, ECM-related protein, its receptor integrins and ECM-remodeling enzymes. The expression levels of these genes that were up-regulated significantly during the testicular fusion were verified by qRT-PCR. The matrix metalloproteinases (MMPs) were found to be the main enzymes related to the ECM degradation and to contribute to the testicular fusion. The testis was not able to fuse if MMPs inhibitor GM6001 was injected into the 5th abdomen region.Conclusions The transcriptome and DEGs analysis of the testes at L6D4, L6D6, P4D stages provided genes expression information related to the testicular fusion in S. litura . These results indicated that cytoskeleton proteins, ECM-integrin interaction genes and ECM-related proteins was involved in cell migration, adhesion and fusion during the testicular fusion. The ECM degradation enzymes MMPs probably play a critical role in the fusion of testis.

scholarly journals Transcriptomic analysis of the testicular fusion in Spodoptera litura

2019 ◽  
Author(s):  
Yaqing Chen ◽  
Jun Ou ◽  
Yucheng Liu ◽  
Qiong Wu ◽  
Liang Wen ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Critical Role ◽  
Gonad Development ◽  
Signal Transduction Pathway ◽  
Rna Seq ◽  
Agricultural Pests ◽  
Ecm Remodeling ◽  
Plant Feeding ◽  
The Matrix ◽  
Ecm Degradation

Abstract Background Lepidoptera is one group of the largest plant-feeding insects and Spodoptera litura (Lepidoptera: Noctuidae) is one of the most serious agricultural pests in Asia countries. An interesting and unique phenomenon for gonad development of Lepidoptera is the testicular fusion. Two separated testes fused into a single one during the larva-to-pupa metamorphosis, which is believed to contribute to sperm production and the prevalence in field. To study the molecular mechanism of the testicular fusion, RNA sequencing (RNA-seq) experiments of the testes from 4-day-old sixth instar larvae (L6D4) (before fusion), 6-day-old sixth instar larvae (L6D6, prepupae) (on fusing) and 4-day-old pupae (P4D) (after fusion) of S. litura were performed.Results RNA-seq data of the testes showed that totally 12,339 transcripts were expressed at L6D4, L6D6 and P4D stages. A large number of differentially expressed genes (DEGs) were up-regulated from L6D4 to L6D6, and then more genes were down-regulated from L6D6 to P4D. The DEGs mainly belongs to the genes related to the 20E signal transduction pathway, transcription factors, chitin metabolism related enzymes, the families of cytoskeleton proteins, extracellular matrix (ECM) components, ECM-related protein, its receptor integrins and ECM-remodeling enzymes. The expression levels of these genes that were up-regulated significantly during the testicular fusion were verified by qRT-PCR. The matrix metalloproteinases (MMPs) were found to be the main enzymes related to the ECM degradation and to contribute to the testicular fusion. The testis was not able to fuse if MMPs inhibitor GM6001 was injected into the 5th abdomen region.Conclusions The transcriptome and DEGs analysis of the testes at L6D4, L6D6, P4D stages provided genes expression information related to the testicular fusion in S. litura . These results indicated that cytoskeleton proteins, ECM-integrin interaction genes and ECM-related proteins was involved in cell migration, adhesion and fusion during the testicular fusion. The ECM degradation enzymes MMPs probably play a critical role in the fusion of testis.

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