scholarly journals The Ultrastructure of Mosquitoes : 2. Malpighian tubule of Culex pipiens pallens

1969 ◽  
Vol 20 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Setsuo Suguri ◽  
Yasumasa Tongu ◽  
Kazuo Itano ◽  
Daigoro Sakumoto ◽  
Seiiti Inatomi
Keyword(s):  
Culex Pipiens ◽  
Malpighian Tubule ◽  
Culex Pipiens Pallens ◽  
Pipiens Pallens

scholarly journals Enzymology, Histological and Ultrastructural Effects of Ar-Turmerone on Culex pipiens pallens Larvae

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 336
Author(s):  
Jia Liu ◽  
Diana Fernandez ◽  
Yanjin Gao ◽  
Pierre Silvie ◽  
Yongdong Gao ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Active Sites ◽  
Malpighian Tubule ◽  
Muscle Cells ◽  
Fourth Instar ◽  
Culex Pipiens Pallens ◽  
Detoxifying Enzymes ◽  
Transmission Electron ◽  
Ventral Muscle ◽  
Pipiens Pallens

Our previous article demonstrated that ar-turmerone ((6S)-2-methyl-6-(4-methylphenyl)-2-hepten-4-one) extracted from Curcuma longa L. has a significant larvicidal activity against the fourth instar larvae of Culex pipiens pallens. To reveal the effects of ar-turmerone on C. pipiens pallens larvae, light microscopy and transmission electron microscopy were used to observe the histological and ultrastructure changes in muscle and digestive tissues of fourth instar larvae. It was also revealed by detecting the activity of the acetylcholinesterase (AChE) enzyme and three detoxifying enzymes, including carboxylesterase (CarE), glutathione-S-transferase (GST) and Cytochrome P450 monooxidases (P450). The observation under the light microscope showed that the larvae displayed a disruption of myofibril in ventral muscle cells, the disappearance of nucleolus in the malpighian tubule cells, and the exfoliation of the brush border in midgut epithelial cells, 24 h after treatment. The observation under the transmission electron microscope displayed disorganized Z-lines in the ventral muscle cells, and dissolved membrane of mitochondria, nuclear and endoplasmic reticulum in abdominal cells. The enzymatic activity results showed that ar-turmerone significantly increased the level of detoxifying enzymes, while the activity of AChE was not obviously affected. All the results suggest that the larvicidal mechanism of ar-turmerone is estimated to be stomach poison and the active sites might be the muscle and digestive tissues, and the mode of action of ar-turmerone may be unrelated to AChE.

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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