scholarly journals RNAi-Mediated Silencing of the Chitinase 5 Gene for Fall Webworm (Hyphantria cunea) Can Inhibit Larval Molting Depending on the Timing of dsRNA Injection

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 406
Author(s):  
Xun Zhang ◽  
Yue Wang ◽  
Sufang Zhang ◽  
Xiangbo Kong ◽  
Fu Liu ◽  
...  
Keyword(s):  
Gene Function ◽  
Chitinase Gene ◽  
Developmental Expression ◽  
Hyphantria Cunea ◽  
Double Stranded Rna ◽  
Real Time Quantitative Pcr ◽  
Molting Process ◽  
Group I ◽  
Its Gene ◽  
Dsrna Injection

Chitinases, which are crucial enzymes required for chitin degradation and reconstruction, are often selectively considered to be effective molecular targets for pest control due to their critical roles in insect development. Although the Hyphantria cunea chitinase gene has been reported previously, its sequence characteristics, gene function, and feasibility as a potential target for pest management were absent. In the present study, we characterized the H. cunea chitinase gene and designated it HcCht5. Phylogenic and domain structure analysis suggested that HcCht5 contained the typical chitinase features and was clustered into chitinase group I. Tissue-specific and developmental expression pattern analysis with Real-Time Quantitative PCR (RT-qPCR) showed that HcCht5 was mainly expressed in the integument tissues and that the transcript levels peaked during molting. RNA interference (RNAi)-mediated silencing of HcCht5 caused 33.3% (2 ug) and 66.7% (4 ug) mortality rates after double-stranded RNA (dsRNA) injection. Importantly, the interference efficiency of HcCht5 depended on the injection time of double-stranded RNA (dsRNA), as the pre-molting treatment achieved molt arrest more effectively. In addition, transcriptome sequencing (RNA-seq) analysis of RNAi samples demonstrated silencing of the down-regulated HcCht5 genes related to chitin metabolism and molting hormone signaling, as well as genes related to detoxification metabolism. Our results indicate the essential role of HcCht5 in H. cunea development and detail the involvement of its gene function in the larval molting process.

scholarly journals The expression of microRNA-331-3p and microRNA-23b3 in Egyptian patients with early-stage hepatocellular carcinoma in hepatitis C-related liver cirrhosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reham A. Aboelwafa ◽  
Walid Ismail Ellakany ◽  
Marwa A. Gamaleldin ◽  
Marwa A. Saad
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Cirrhosis ◽  
Hepatitis C ◽  
Early Stage ◽  
Group Iii ◽  
Real Time Quantitative Pcr ◽  
Early Stages ◽  
Group I ◽  
Egyptian Patients ◽  
Cirrhotic Patients

Abstract Background Hepatocellular carcinoma and hepatitis C are strongly associated. The current work aimed to study the expression levels of microRNA-331-3p and microRNA-23b-3p as propable biomarkers for detecting liver cancer (HCC) at its early stages in patients with HCV-related liver cirrhosis. The current prospective study included two hundred participants, divided into three groups: group I, 100 patients with HCV-related liver cirrhosis; group II, 50 HCC patients at early stages; and group III, 50 apparentlyhealthy controls. All patients had routine laboratory workup and ultrasound hepatic assessment. Values of microRNA-331-3p and microRNA-23b-3p were measured by real-time quantitative PCR. Results Levels of miR-331-3p were significantly higher in HCC patients than in cirrhotic patients and controls (p < 0.001), while levels of miR-23b-3p were significantly lower in HCC patients compared to cirrhotics and controls (p < 0.001). ROC curve revealed that miR-23b-3p had 80% sensitivity and 74% specificity, miR-331-3p had 66% sensitivity and 61% specificity, and AFP had 64% sensitivity and 61% specificity of 61% in discrimination between HCC patients from controls. Conclusion Serum miR-23b-3p is a more effective predictor than miR-331-3p and AFP for the development of hepatocellular carcinoma in hepatitis C (HCV)-related cirrhotic patients.

scholarly journals Chitinase Gene Sequences Retrieved from Diverse Aquatic Habitats Reveal Environment-Specific Distributions

2004 ◽  
Vol 70 (12) ◽  
pp. 6977-6983 ◽  
Author(s):  
Gary R. LeCleir ◽  
Alison Buchan ◽  
James T. Hollibaugh
Keyword(s):  
Water Column ◽  
Chitinase Gene ◽  
Mono Lake ◽  
Hypersaline Lake ◽  
Sargasso Sea ◽  
Gene Sequences ◽  
Central Arctic Ocean ◽  
Sediment Samples ◽  
Group I ◽  
Chitinase Genes

ABSTRACT Chitin is an abundant biopolymer whose degradation is mediated primarily by bacterial chitinases. We developed a degenerate PCR primer set to amplify a ∼900-bp fragment of family 18, group I chitinase genes and used it to retrieve these gene fragments from environmental samples. Clone libraries of presumptive chitinase genes were created for nine water and six sediment samples from 10 aquatic environments including freshwater and saline lakes, estuarine water and sediments, and the central Arctic Ocean. Putative chitinase sequences were also retrieved from the Sargasso Sea metagenome sequence database. We were unable to obtain PCR product with these primers from an alkaline, hypersaline lake (Mono Lake, California). In total, 108 partial chitinase gene sequences were analyzed, with a minimum of 5 and a maximum of 13 chitinase sequences obtained from each library. All chitinase sequences were novel compared to previously identified sequences. Intralibrary sequence diversity was low, while we found significant differences between libraries from different water column samples and between water column and sediment samples. However, identical sequences were retrieved from samples collected at widely distributed locations that did not necessarily represent similar environments, suggesting homogeneity of chitinoclastic communities between some environments.

Specific interference with gene function by double-stranded RNA in early mouse development

1999 ◽  
Vol 2 (2) ◽  
pp. 70-75 ◽  
Author(s):  
Florence Wianny ◽  
Magdalena Zernicka-Goetz
Keyword(s):  
Gene Function ◽  
Mouse Development ◽  
Double Stranded Rna ◽  
Early Mouse

scholarly journals New strains for tissue-specific RNAi studies in Caenorhabditis elegans

2018 ◽  
Author(s):  
Jason S. Watts ◽  
Henry F. Harrison ◽  
Shizue Omi ◽  
Quentin Guenthers ◽  
James Dalelio ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Caenorhabditis Elegans ◽  
Gene Function ◽  
Target Genes ◽  
Resistant Mutant ◽  
Knockout Mutant ◽  
Tissue Specific ◽  
Double Stranded Rna ◽  
C Elegans ◽  
Insight Into

AbstractRNA interference is a powerful tool for dissecting gene function. In Caenorhabditis elegans, ingestion of double stranded RNA causes strong, systemic knockdown of target genes. Further insight into gene function can be revealed by tissue-specific RNAi techniques. Currently available tissue-specific C. elegans strains rely on rescue of RNAi function in a desired tissue or cell in an otherwise RNAi deficient genetic background. We attempted to assess the contribution of specific tissues to polyunsaturated fatty acid (PUFA) synthesis using currently available tissue-specific RNAi strains. We discovered that rde-1 (ne219), a commonly used RNAi-resistant mutant strain, retains considerable RNAi capacity against RNAi directed at PUFA synthesis genes. By measuring changes in the fatty acid products of the desaturase enzymes that synthesize PUFAs, we found that the before mentioned strain, rde-1 (ne219) and the reported germline only RNAi strain, rrf-1 (pk1417) are not appropriate genetic backgrounds for tissue-specific RNAi experiments. However, the knockout mutant rde-1 (ne300) was strongly resistant to dsRNA induced RNAi, and thus is more appropriate for construction of a robust tissue-specific RNAi strains. Using newly constructed strains in the rde-1(null) background, we found considerable desaturase activity in intestinal, epidermal, and germline tissues, but not in muscle. The RNAi-specific strains reported in this study will be useful tools for C. elegans researchers studying a variety of biological processes.

scholarly journals Intron-assisted, viroid-based production of insecticidal circular double-stranded RNA in Escherichia coli

2020 ◽  
Author(s):  
Beltrán Ortolá ◽  
Teresa Cordero ◽  
Xu Hu ◽  
José-Antonio Daròs
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Rna Stability ◽  
Diabrotica Virgifera Virgifera ◽  
Septate Junction ◽  
Circular Rnas ◽  
Double Stranded Rna ◽  
E Coli ◽  
Group I ◽  
Insecticide Activity

ABSTRACTRNA interference (RNAi) is a natural mechanism for protecting against harmful genetic elements and regulating gene expression, which can be artificially triggered by the delivery of homologous double-stranded RNA (dsRNA). This mechanism can be exploited as a highly specific and environmentally friendly pest control strategy. To this aim, systems for producing large amounts of recombinant dsRNA are necessary. We describe a system to efficiently produce large amounts of circular dsRNA in Escherichia coli and demonstrate the efficient insecticidal activity of these molecules against Western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte), a highly damaging pest of corn crops. In our system, the two strands of the dsRNA are expressed in E. coli embedded within the very stable scaffold of Eggplant latent viroid (ELVd), a small circular non-coding RNA. Stability in E. coli of the corresponding plasmids with long inverted repeats was achieved by using a cDNA coding for a group-I autocatalytic intron from Tetrahymena thermophila as a spacer. RNA circularization and large-scale accumulation in E. coli cells was facilitated by co-expression of eggplant tRNA ligase, the enzyme that ligates ELVd during replication in the host plant. The inserted intron efficiently self-spliced from the RNA product during transcription. Circular RNAs containing a dsRNA moiety homologous to smooth septate junction 1 (DvSSJ1) gene exhibited excellent insecticide activity against WCR larvae. Finally, we show that the viroid scaffold can be separated from the final circular dsRNA product using a second T. thermophila self-splicing intron in a permuted form.

Genetic Identification of a New D1-allelic Mutant and Analysis of Its Gene Function in Rice

2016 ◽  
Vol 42 (9) ◽  
pp. 1261 ◽  
Author(s):  
Cui-Hong WANG ◽  
Jian MA ◽  
Shuai WANG ◽  
Peng TIAN ◽  
Chang-Yan QI ◽  
...  
Keyword(s):  
Gene Function ◽  
Genetic Identification ◽  
Its Gene

scholarly journals Selected Chitinase Genes in Cultured and Uncultured Marine Bacteria in the α- and γ-Subclasses of the Proteobacteria

2000 ◽  
Vol 66 (3) ◽  
pp. 1195-1201 ◽  
Author(s):  
Matthew T. Cottrell ◽  
Daniel N. Wood ◽  
Liying Yu ◽  
David L. Kirchman
Keyword(s):  
Marine Bacteria ◽  
Pcr Primers ◽  
Chitinase Gene ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bacterial Strains ◽  
Chitin Degradation ◽  
Group I ◽  
Degrading Bacteria ◽  
Chitinase Genes

ABSTRACT PCR primers were patterned after chitinase genes in four γ-proteobacteria in the families Alteromonadaceae andEnterobacteriaceae (group I chitinases) and used to explore the occurrence and diversity of these chitinase genes in cultured and uncultured marine bacteria. The PCR results from 104 bacterial strains indicated that this type of chitinase gene occurs in two major groups of marine bacteria, α- and γ-proteobacteria, but not theCytophaga-Flavobacter group. Group I chitinase genes also occur in some viruses infecting arthropods. Phylogenetic analysis indicated that similar group I chitinase genes occur in taxonomically related bacteria. However, the overall phylogeny of chitinase genes did not correspond to the phylogeny of 16S rRNA genes, possibly due to lateral transfer of chitinase genes between groups of bacteria, but other mechanisms, such as gene duplication, cannot be ruled out. Clone libraries of chitinase gene fragments amplified from coastal Pacific Ocean and estuarine Delaware Bay bacterioplankton revealed similarities and differences between cultured and uncultured bacteria. We had hypothesized that cultured and uncultured chitin-degrading bacteria would be very different, but in fact, clones having nucleotide sequences identical to those of chitinase genes of cultured α-proteobacteria dominated both libraries. The other clones were similar but not identical to genes in cultured γ-proteobacteria, including vibrios and alteromonads. Our results suggest that a closer examination of chitin degradation by α-proteobacteria will lead to a better understanding of chitin degradation in the ocean.

Characterisation and developmental expression of a chitinase gene in Heterodera glycines

2002 ◽  
Vol 32 (10) ◽  
pp. 1293-1300 ◽  
Author(s):  
Bingli Gao ◽  
R Allen ◽  
Tom Maier ◽  
Jeff P McDermott ◽  
Eric L Davis ◽  
...  
Keyword(s):  
Heterodera Glycines ◽  
Chitinase Gene ◽  
Developmental Expression

scholarly journals Plant Functional Genomics in A Few Days: Laser-Assisted Delivery of Double-Stranded RNA to Higher Plants

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 93
Author(s):  
Nabil Killiny ◽  
Pedro Gonzalez-Blanco ◽  
Siddarame Gowda ◽  
Xavier Martini ◽  
Ed Etxeberria
Keyword(s):  
Transgenic Plants ◽  
Gene Function ◽  
Citrus Tristeza Virus ◽  
Higher Plants ◽  
Double Stranded Rna ◽  
Assisted Delivery ◽  
Endogenous Genes ◽  
Citrus Leaves ◽  
Tristeza Virus ◽  
Citrus Trees

The technology of transgenic plants is challenging and time consuming, especially for higher plants and trees such as citrus. Double-stranded RNA (dsRNA) delivery via a plant virus is an alternative method to create transgenic plants by suppressing the expression of plant endogenous genes. Citrus tristeza virus-based vector has been constructed specifically for use in citrus trees. However, this is time-consuming, as it can take up to nine months to produce the desired phenotype. Here we describe a much faster method for the study of gene function in citrus trees. In the current study, we used laser light for the delivery of dsRNA to citrus leaves. We targeted the endogenous reporter gene phytoene desaturase (PDS) and obtained the classical phenotype (leaf bleaching) in only three days after the laser-assisted delivery. Interestingly, the phenotype response was systemic, which indicates the movement of dsRNA and/or ssRNA within the plants. In addition, dsRNAs were taken up by phloem cells and the bleaching phenotype was clear around the main veins. In conclusion, the delivery of dsRNA to plants through laser treatment may provide a fast and more specific tool to study the gene function in higher plants and trees.

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