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 Physiological characterization of chitin synthase A responsible for the biosynthesis of cuticle chitin in Culex pipiens pallens (Diptera: Culicidae)

2021 ◽  
Vol 14 (1) ◽  
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 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) is a crucial enzyme in chitin synthesis; therefore, identifying and characterizing how CHSA determines chitin content may contribute to the development of novel vector control strategies. Results The injection of small interfering RNA targeting CHSA (siCHSA) to knockdown CHSA transcripts in larval, pupal and adult stages of Culex pipiens pallens resulted in the appearance of different lethal phenotypes. When larval and pupal stages were injected with siCHSA, 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. When siCHSA was injected into mosquitoes in the adult stage, CHSA knockdown also affected the laminar organization of the mesoderm and the formation of pseudo-orthogonal patterns of the large fibers of the endoderm. Conclusion We provide a systematic and comprehensive description of the effects of CHSA on morphogenesis and metamorphosis. The results show that CHSA not only affects chitin synthesis during molting, but also might be involved in chitin degradation. Our results further show that CHSA is important for the structural integrity of the adult mosquito cuticle. Graphic abstract

scholarly journals MiR-4448 is involved in deltamethrin resistance by targeting CYP4H31 in Culex pipiens pallens

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xixi Li ◽  
Shengli Hu ◽  
Haitao Yin ◽  
Hongbo Zhang ◽  
Dan Zhou ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Oral Feeding ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Culex Pipiens Pallens ◽  
Deltamethrin Resistance ◽  
Regulatory Functions ◽  
Pipiens Pallens

Abstract Background Culex pipiens (Cx. pipiens) complex, which acts as a vector of viruses and is widespread and abundant worldwide, including West Nile virus, Japanese encephalitis virus, and Sindbis virus, can cause serious vector-borne diseases affecting human health. Unfortunately, mosquitoes have developed deltamethrin resistance because of its long-term overuse, representing a major challenge to mosquito control. Understanding the molecular regulatory mechanisms of resistance is vital to control mosquitoes. MicroRNAs (miRNAs) are short non-coding RNAs that have been demonstrated to be important regulators of gene expression across a wide variety of organisms, which might function in mosquito deltamethrin resistance. In the present study, we aimed to investigate the regulatory functions of miR-4448 and CYP4H31 in the formation of insecticidal resistance in mosquito Culex pipiens pallens. Methods We used quantitative real-time reverse transcription PCR to measure miR-4448 and CYP4H31 (encoding a cytochrome P450) expression levels. The regulatory functions of miR-4448 and CYP4H31 were assessed using dual-luciferase reporter assays. Then, oral feeding, RNA interference, and the American Centers for Disease Control and Prevention bottle bioassay were used to determine miR-4448’s association with deltamethrin resistance by targeting CYP4H31in vivo. Cell Counting Kit-8 (CCK-8) was also used to detect the viability of pIB/V5-His-CYP4H31-transfected C6/36 cells after deltamethrin treatment in vitro. Results MiR-4448 was downregulated in the deltamethrin-resistant strain (DR strain), whereas CYP4H31 was downregulated in deltamethrin-susceptible strain. CYP4H31 expression was downregulated by miR-4448 recognizing and binding to its 3′ untranslated region. Functional verification experiments showed that miR-4448 overexpression resulted in lower expression of CYP4H31. The mortality of miR-4448 mimic-injected DR strain mosquitoes was higher than that of the controls. CCK-8 assays showed that CYP4H31 decreased cellular resistance to deltamethrin in vitro and the mortality of the DR strain increased when CYP4H31 was knocked down in vivo. Conclusions In mosquitoes, miR-4448 participates in deltamethrin resistance by targeting CYP4H31. The results of the present study increase our understanding of deltamethrin resistance mechanisms.

Feeding on different attractive flowering plants affects the energy reserves of Culex pipiens pallens adults

2017 ◽  
Vol 117 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Bao-Ting Yu ◽  
Yin Hu ◽  
Yan-Mei Ding ◽  
Jia-Xin Tian ◽  
Jian-Chu Mo
Keyword(s):  
Culex Pipiens ◽  
Flowering Plants ◽  
Energy Reserves ◽  
Culex Pipiens Pallens ◽  
Pipiens Pallens

scholarly journals Cloning and Expression of Two Crystal Protein Genes, cry30Ba1 and cry44Aa1, Obtained from a Highly Mosquitocidal Strain, Bacillus thuringiensis subsp. entomocidus INA288

2006 ◽  
Vol 72 (8) ◽  
pp. 5673-5676 ◽  
Author(s):  
Takeshi Ito ◽  
Tomonori Ikeya ◽  
Ken Sahara ◽  
Hisanori Bando ◽  
Shin-ichiro Asano
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Crystal Protein ◽  
Cloning And Expression ◽  
Culex Pipiens Pallens ◽  
Bacillus Thuringiensis Subsp ◽  
Pipiens Pallens ◽  
Crystal Protein Genes

ABSTRACT Two novel crystal protein genes, cry30Ba and cry44Aa, were cloned from Bacillus thuringiensis subsp. entomocidus INA288 and expressed in an acrystalliferous strain. Cry44Aa crystals were highly toxic to second-instar Culex pipiens pallens (50% mortality concentration [LC50] = 6 ng/ml) and Aedes aegypti (LC50 = 12 ng/ml); however, Cry30Ba crystals were not toxic.

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