scholarly journals Chitin Synthesis and Degradation in Crustaceans: A Genomic View and Application

Marine Drugs ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 153
Author(s):  
Xiaojun Zhang ◽  
Jianbo Yuan ◽  
Fuhua Li ◽  
Jianhai Xiang
Keyword(s):  
Immune Defense ◽  
Sequencing Technology ◽  
Chitin Synthesis ◽  
Chitin Degradation ◽  
Genomic Analyses ◽  
Potential Applications ◽  
Multiple Copies ◽  
Gene Structure And Expression ◽  
Chitinase Genes ◽  
Synthesis And Degradation

Chitin is among the most important components of the crustacean cuticular exoskeleton and intestinal peritrophic matrix. With the progress of genomics and sequencing technology, a large number of gene sequences related to chitin metabolism have been deposited in the GenBank database in recent years. Here, we summarized the genes and pathways associated with the biosynthesis and degradation of chitins in crustaceans based on genomic analyses. We found that chitin biosynthesis genes typically occur in single or two copies, whereas chitin degradation genes are all multiple copies. Moreover, the chitinase genes are significantly expanded in most crustacean genomes. The gene structure and expression pattern of these genes are similar to those of insects, albeit with some specific characteristics. Additionally, the potential applications of the chitin metabolism genes in molting regulation and immune defense, as well as industrial chitin degradation and production, are also summarized in this review.

scholarly journals Melanin Externalization in Candida albicans Depends on Cell Wall Chitin Structures

2010 ◽  
Vol 9 (9) ◽  
pp. 1329-1342 ◽  
Author(s):  
Claire A. Walker ◽  
Beatriz L. Gómez ◽  
Héctor M. Mora-Montes ◽  
Kevin S. Mackenzie ◽  
Carol A. Munro ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Fungal Pathogen ◽  
Cell Walls ◽  
Chitin Synthesis ◽  
Melanin Production ◽  
Content Type ◽  
Encoding Gene ◽  
Chitinase Genes

ABSTRACT The fungal pathogen Candida albicans produces dark-pigmented melanin after 3 to 4 days of incubation in medium containing l-3,4-dihydroxyphenylalanine (l-DOPA) as a substrate. Expression profiling of C. albicans revealed very few genes significantly up- or downregulated by growth in l-DOPA. We were unable to determine a possible role for melanin in the virulence of C. albicans. However, we showed that melanin was externalized from the fungal cells in the form of electron-dense melanosomes that were free or often loosely bound to the cell wall exterior. Melanin production was boosted by the addition of N-acetylglucosamine to the medium, indicating a possible association between melanin production and chitin synthesis. Melanin externalization was blocked in a mutant specifically disrupted in the chitin synthase-encoding gene CHS2. Melanosomes remained within the outermost cell wall layers in chs3Δ and chs2Δ chs3Δ mutants but were fully externalized in chs8Δ and chs2Δ chs8Δ mutants. All the CHS mutants synthesized dark pigment at equivalent rates from mixed membrane fractions in vitro, suggesting it was the form of chitin structure produced by the enzymes, not the enzymes themselves, that was involved in the melanin externalization process. Mutants with single and double disruptions of the chitinase genes CHT2 and CHT3 and the chitin pathway regulator ECM33 also showed impaired melanin externalization. We hypothesize that the chitin product of Chs3 forms a scaffold essential for normal externalization of melanosomes, while the Chs8 chitin product, probably produced in cell walls in greater quantity in the absence of CHS2, impedes externalization.

scholarly journals Development-Disrupting Chitin Synthesis Inhibitor, Novaluron, Reprogramming the Chitin Degradation Mechanism of Red Palm Weevils

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4304 ◽  
Author(s):  
Abid Hussain ◽  
Ahmed Mohammed AlJabr ◽  
Hassan Al-Ayedh
Keyword(s):  
Expression Patterns ◽  
Invasive Pest ◽  
Chitin Synthesis ◽  
Red Palm Weevil ◽  
Synthesis Inhibitor ◽  
Chitin Degradation ◽  
Palm Weevil ◽  
Chitin Synthesis Inhibitor ◽  
Mortality Response ◽  
Study Laboratory

Disruption in chitin regulation by using chitin synthesis inhibitor (novaluron) was investigated to gain insights into the biological activity of chitinase in red palm weevils, an invasive pest of date palms in the Middle East. Impact of novaluron against ninth instar red palm weevil larvae was examined by dose-mortality response bioassays, nutritional indices, and expression patterns of chitinase genes characterized in this study. Laboratory bioassays revealed dose-dependent mortality response of ninth-instar red palm weevil larvae with LD50 of 14.77 ppm of novaluron. Dietary growth analysis performed using different doses of novaluron (30, 25, 20, 15, 10, and 5 ppm) exhibited very high reduction in their indexes such as Efficacy of Conversion of Digested Food (82.38%) and Efficacy of Conversion of Ingested Food (74.27%), compared with control treatment. Transcriptomic analysis of red palm weevil larvae characterized numerous genes involved in chitin degradation including chitinase, chitinase-3-like protein 2, chitinase domain-containing protein 1, Endochitinase-like, chitinase 3, and chitin binding peritrophin-a domain. However, quantitative expression patterns of these genes in response to novaluron-fed larvae revealed tissue-specific time-dependent expression patterns. We recorded overexpression of all genes from mid-gut tissues. Growth retarding, chitin remodeling and larvicidal potential suggest novaluron as a promising alternate for Rhynchophorus ferrugineus management.

scholarly journals Monitoring of Enzymatic Proteolysis Using Self-Assembled Quantum Dot-Protein Substrate Sensors

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Aaron R. Clapp ◽  
Ellen R. Goldman ◽  
H. Tetsuo Uyeda ◽  
Eddie L. Chang ◽  
Jessica L. Whitley ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Proteolytic Enzymes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Enzymatic Digestion ◽  
Enzymatic Proteolysis ◽  
Potential Applications ◽  
Multiple Copies ◽  
Self Assembled

We have previously utilized hybrid semiconductor quantum dot- (QD-) peptide substrates for monitoring of enzymatic proteolysis. In this report, we expand on this sensing strategy to further monitor protein-protease interactions. We utilize QDs self-assembled with multiple copies of dye-labeled proteins as substrates for the sensing of protease activity. Detection of proteolysis is based on changes in the rate of fluorescence resonance energy transfer (FRET) between the QDs and the proximal dye-labeled proteins following protein digestion by added enzyme. Our study focused on two representative proteolytic enzymes: the cysteine protease papain and the serine protease endoproteinase K. Analysis of the enzymatic digestion allowed us to estimate minimal values for the enzymatic activities of each enzyme used. Mechanisms of enzymatic inhibition were also inferred from the FRET data collected in the presence of inhibitors. Potential applications of this technology include drug discovery assays and in vivo cellular monitoring of enzymatic activity.

Transcriptome analysis of Tetranychus cinnabarinus responses to an insecticide exposure

2020 ◽  
Vol 25 (7) ◽  
pp. 1329-1342
Author(s):  
Jia Chen ◽  
Xianyan Ye ◽  
Jing Wang ◽  
Bin Xia ◽  
Tianrong Xin
Keyword(s):  
Gene Expression ◽  
Differentially Expressed Genes ◽  
Degradation Pathway ◽  
Differentially Expressed ◽  
Detoxification Enzymes ◽  
Tetranychus Cinnabarinus ◽  
Glutathione S Transferase ◽  
Chitin Synthesis ◽  
Sublethal Concentrations ◽  
Synthesis And Degradation

Diflubenzuron, a benzoylphenylurea insecticide that interferes with chitin biosynthesis, causes arthropods to moult abnormally and die. However, its mechanism of action in Tetranychus cinnabarinus is still unclear. In order to explore the effects of different sublethal concentrations of diflubenzuron on T. cinnabarinus, we conducted a high-throughput RNA-seq technology to identify the variations in transcriptomic profile of T. cinnabarinus larvae. The results revealed that 470 and 49 differentially expressed genes were identified in LC50-and LC70-treated groups, comparing with the control. We also identified and analyzed the detoxification enzymes involved in the transcritome of T. cinnabarinus, including 34 cytochrome P450 genes, 17 glutathione-s-transferase genes (GSTs), 12 acetylcholinesterase genes (AChEs) and 9 ABC transporter genes. In addition, differentially expressed genes analysis showed that the gene expression levels of detoxification enzymes were generally enhanced. At the same time, seven and eleven genes were involved in chitin synthesis and degradation ways, respectively. The expression level of most genes involved in chitin synthesis and degradation pathway were generally up-regulated after exposure to sublethal concentrations of diflubenzuron. Moreover, for transcriptome validation, the mRNA expression results of ten specially expressed genes by quantitative real-time PCR demonstrated that these gene expression trends were consistent with that of the transcriptome data. Together, all these results suggested that sublethal concentrations of diflubenzuron exposure affected gene expression of major detoxification enzymes and chitin metabolism genes in T. cinnabarinus larvae. These findings may be helpful to further understand the possible molecular mechanism of benzoylphenylurea insecticides in T. cinnabarinus, as well as in other spider mites.

scholarly journals Silencing Chitinase Genes Increases Susceptibility ofTetranychus cinnabarinus(Boisduval) to Scopoletin

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hong Zhou ◽  
Yong-qiang Zhang ◽  
Ting Lai ◽  
Dan Wang ◽  
Jin-lin Liu ◽  
...  
Keyword(s):  
Spider Mite ◽  
Control Group ◽  
Life Stages ◽  
Tetranychus Cinnabarinus ◽  
Chitin Synthesis ◽  
Synthesis Inhibitor ◽  
Double Stranded Rna ◽  
Chitin Synthesis Inhibitor ◽  
Major Pest ◽  
Chitinase Genes

The carmine spider miteTetranychus cinnabarinusis a major pest of crop and vegetable plants worldwide. Previous studies have shown that scopoletin is a promising acaricidal compound againstTetranychus cinnabarinus.However, the acaricidal mechanism of scopoletin remains unclear. In the present study, 12 full-length cDNAs of chitinase (CHIT) genes fromTetranychus cinnabarinus(designatedTcCHITs) were cloned and characterized. AlthoughTcCHITswere expressed throughout all life stages, their expression levels were significantly upregulated during the larval and nymphal stages.TcCHITswere downregulated 24 h after treatment with scopoletin and upregulated 24 h after treatment with diflubenzuron (DFB, a chitin synthesis inhibitor). Feeding double-stranded RNA effectively silencedTcCHITtranscription inTetranychus cinnabarinus, thus increasing its susceptibility to scopoletin but reducing that to DFB. Meanwhile,TcCHITsilencing in larvae and adult resulted in an extremely low molting rate (7.3%) and high mortality rate (53.3%), respectively, compared with those in the control group. CHIT genes are closely related to arthropod survival, molting, and development inTetranychus cinnabarinus, suggesting that acaricidal mechanisms of scopoletin and DFB may occur by inhibition and activation of CHIT gene expression, respectively.TcCHITconstitutes a possible target of scopoletin and DFB inTetranychus cinnabarinus.

Nuclear receptor HR3 controls locust molt by regulating chitin synthesis and degradation genes of Locusta migratoria

2018 ◽  
Vol 92 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaoming Zhao ◽  
Zhongyu Qin ◽  
Weimin Liu ◽  
Xiaojian Liu ◽  
Bernard Moussian ◽  
...  
Keyword(s):  
Nuclear Receptor ◽  
Locusta Migratoria ◽  
Chitin Synthesis ◽  
Synthesis And Degradation

scholarly journals Physiological Characterization of the Chitin Synthase A Gene Responsible for Biosynthesis of Cuticle Chitin in Culex Pipiens Pallens (Diptera: Culicidae)

2021 ◽  
Author(s):  
Xiaoshan Yang ◽  
Yang Xu ◽  
Qi Yin ◽  
Hongbo Zhang ◽  
Haitao Yin ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Structural Integrity ◽  
Higher Plants ◽  
Control Strategies ◽  
Chitin Synthase ◽  
Adult Mosquito ◽  
Culex Pipiens Pallens ◽  
Chitin Synthesis ◽  
Chitin Degradation ◽  
Pipiens Pallens

Abstract Background: The pathogens transmitted by mosquitoes (Culex pipiens pallens) to humans and animals cause several emerging and resurgent infectious diseases. Increasing insecticide resistance requires rational action to control the target vector population. Chitin is indispensable for insect growth and development and absent from vertebrates and higher plants. Chitin synthase A (CHSA) represents a crucial enzyme in chitin synthesis; therefore, identifying and characterizing how CHSA determines the chitin content might help with novel vector control strategies. Results: The injection of small interfering RNA targeting CHSA (siCHSA) to knock down CHSA transcripts of in larval, pupal, and adult stages, showed different lethal phenotypes. In the larval and pupal stages, CHSA knockdown prevented larval molting, pupation, and adult eclosion, and affected the production of chitin and chitin degradation, which resulted in an ecdysis defect phenotype of mosquitoes. In the adult stage, it also affected the laminar organization of mesoderm and the formation of pseudo orthogonally large fibers of the endoderm. Conclusion: The present study provides a systematic and comprehensive description of the effects of CHSA on morphogenesis and metamorphosis. The results showed that CHSA not only affects chitin synthesis during molting, but also might be involved in chitin degradation. Our result further showed that CHSA is important for the structural integrity of the adult mosquito cuticle.

scholarly journals Linked-read sequencing enables haplotype-resolved resequencing at population scale

2020 ◽  
Author(s):  
Dave Lutgen ◽  
Raphael Ritter ◽  
Remi-André Olsen ◽  
Holger Schielzeth ◽  
Joel Gruselius ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Sequencing Data ◽  
Sequencing Technology ◽  
Genome Resequencing ◽  
High Coverage ◽  
Population Genomic ◽  
Genomic Analyses ◽  
History Of ◽  
Population Scale ◽  
Haplotype Information

AbstractThe feasibility to sequence entire genomes of virtually any organism provides unprecedented insights into the evolutionary history of populations and species. Nevertheless, many population genomic inferences – including the quantification and dating of admixture, introgression and demographic events, and the inference of selective sweeps – are still limited by the lack of high-quality haplotype information. In this respect, the newest generation of sequencing technology now promises significant progress. To establish the feasibility of haplotype-resolved genome resequencing at population scale, we investigated properties of linked-read sequencing data of songbirds of the genus Oenanthe across a range of sequencing depths. Our results based on the comparison of downsampled (25x, 20x, 15x, 10x, 7x, and 5x) with high-coverage data (46-68x) of seven bird genomes suggest that phasing contiguities and accuracies adequate for most population genomic analyses can be reached already with moderate sequencing effort. At 15x coverage, phased haplotypes span about 90% of the genome assembly, with 50 and 90 percent of the phased sequence located in phase blocks longer than 1.25-4.6 Mb (N50) and 0.27-0.72 Mb (N90), respectively. Phasing accuracy reaches beyond 99% starting from 15x coverage. Higher coverages yielded higher contiguities (up to about 7 Mb/1Mb (N50/N90) at 25x coverage), but only marginally improved phasing accuracy. Finally, phasing contiguity improved with input DNA molecule length; thus, higher-quality DNA may help keeping sequencing costs at bay. In conclusion, even for organisms with gigabase-sized genomes like birds, linked-read sequencing at moderate depth opens an affordable avenue towards haplotype-resolved genome resequencing data at population scale.

scholarly journals Impact of Genomics on Clarifying the Evolutionary Relationships amongst Mycobacteria: Identification of Molecular Signatures Specific for the Tuberculosis-Complex of Bacteria with Potential Applications for Novel Diagnostics and Therapeutics

2018 ◽  
Vol 7 (4) ◽  
pp. 31 ◽  
Author(s):  
Radhey S. Gupta
Keyword(s):  
Comparative Genomic ◽  
Drug Resistant ◽  
Cellular Functions ◽  
Tuberculosis Complex ◽  
Genomic Analyses ◽  
Potential Applications ◽  
Resistant Strains ◽  
Novel Interactions ◽  
Drug Resistant Strains ◽  
High Degree

An alarming increase in tuberculosis (TB) caused by drug-resistant strains of Mycobacterium tuberculosis has created an urgent need for new antituberculosis drugs acting via novel mechanisms. Phylogenomic and comparative genomic analyses reviewed here reveal that the TB causing bacteria comprise a small group of organisms differing from all other mycobacteria in numerous regards. Comprehensive analyses of protein sequences from mycobacterial genomes have identified 63 conserved signature inserts and deletions (indels) (CSIs) in important proteins that are distinctive characteristics of the TB-complex of bacteria. The identified CSIs provide potential means for development of novel diagnostics as well as therapeutics for the TB-complex of bacteria based on four key observations: (i) The CSIs exhibit a high degree of exclusivity towards the TB-complex of bacteria; (ii) Earlier work on CSIs provide evidence that they play important/essential functions in the organisms for which they exhibit specificity; (iii) CSIs are located in surface-exposed loops of the proteins implicated in mediating novel interactions; (iv) Homologs of the CSIs containing proteins, or the CSIs in such homologs, are generally not found in humans. Based on these characteristics, it is hypothesized that the high-throughput virtual screening for compounds binding specifically to the CSIs (or CSI containing regions) and thereby inhibiting the cellular functions of the CSIs could lead to the discovery of a novel class of drugs specifically targeting the TB-complex of organisms.

Independent regulation of chitin synthase and chitinase activity in Candida albicans and Saccharomyces cerevisiae

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 921-928 ◽  
Author(s):  
Serena Selvaggini ◽  
Carol A. Munro ◽  
Serge Paschoud ◽  
Dominique Sanglard ◽  
Neil A. R. Gow
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
De Novo ◽  
Gene Families ◽  
Chitinase Activity ◽  
Chitin Synthase ◽  
Chitin Synthesis ◽  
Growing Cell ◽  
Chitinase Genes

Chitin is an essential structural polysaccharide in fungi that is required for cell shape and morphogenesis. One model for wall synthesis at the growing cell surface suggests that the compliance that is necessary for turgor-driven expansion of the cell wall involves a delicate balance of wall synthesis and lysis. Accordingly, de novo chitin synthesis may involve coordinated regulation of members of the CHS chitin synthase and CHT chitinase gene families. To test this hypothesis, the chitin synthase and chitinase activities of cell-free extracts were measured, as well as the chitin content of cell walls isolated from isogenic mutant strains that contained single or multiple knock-outs in members of these two gene families, in both Candida albicans and Saccharomyces cerevisiae. However, deletion of chitinase genes did not markedly affect specific chitin synthase activity, and deletion of single CHS genes had little effect on in vitro specific chitinase activity in either fungus. Chitin synthesis and chitinase production was, however, regulated in C. albicans during yeast–hypha morphogenesis. In C. albicans, the total specific activities of both chitin synthase and chitinase were higher in the hyphal form, which was attributable mainly to the activities of Chs2 and Cht3, respectively. It appeared, therefore, that chitin synthesis and hydrolysis were not coupled, but that both were regulated during yeast–hypha morphogenesis in C. albicans.

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