Hormonal Control of Ovary Development in Mosquitoes

1956 ◽  
Vol 33 (1) ◽  
pp. 211-223 ◽  
Author(s):  
A. N. CLEMENTS
Keyword(s):  
Small Proportion ◽  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Fat Body ◽  
Adult Stage ◽  
Physiological Mechanism ◽  
Blood Feeding ◽  
Hormonal Control ◽  
Ovary Development ◽  
Form Molestus

A study was made of ovary development in Culex pipiens form molestus Forskål, an autogenous mosquito not needing food in the adult stage to develop its eggs, and in C. pipiens pipiens L. and other anautogenous mosquitoes which require blood for ovary development. Comparison of the reserves of fully grown larvae of the autogenous and anautogenous forms of C. pipiens showed that the autogenous form had a rather larger fat body, but that the anautogenous form contained sufficient protein reserves to develop a number of eggs. It was considered that autogeny did not depend solely upon the ability to amass extensive reserves but also upon some other physiological mechanism. Decapitation and ligation at the base of the abdomen prevented ovary development in C. pipiens form molestus when performed within a few hours of emergence, but when performed 7 or more hours after emergence it often failed to prevent ovary development. It is suggested that a gonadotrophic hormone is secreted during this time. Ligation of the abdomen within an hour of feeding on blood appeared to prevent ovary development in Anopheles stephensi Liston. Ovary development occurred in a small proportion of females ligated 2 or more hours after feeding, and this proportion increased with time. Ligation of the abdomen immediately after blood feeding failed to prevent ovary development in Culex pipiens form berbericus Roubaud, Aëdes aegypti (L.) and Anopheles labranchiae atroparvus van Thiel, even in some cases where the ligature was tied within 2-3 min. of the start of feeding.

SALIVARY GLANDS OF FEMALE CULEX PIPIENS: MORPHOLOGICAL CHANGES ASSOCIATED WITH MATURATION AND BLOOD-FEEDING

1975 ◽  
Vol 107 (11) ◽  
pp. 1153-1160 ◽  
Author(s):  
P. M. Barrow ◽  
S. B. McIver ◽  
K. A. Wright
Keyword(s):  
Fine Structure ◽  
Aedes Aegypti ◽  
Salivary Glands ◽  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Morphological Changes ◽  
Neck Region ◽  
Blood Feeding ◽  
Medial Lobe ◽  
Complete Development

AbstractThe salivary glands of female Culex pipiens L each consist of three lobes divisible into five regions. Fine structure indicates that two regions may be involved in solute-linked water transport and three regions may have a glandular function. The fine structure is similar to that reported for Anopheles stephensi and Aedes aegypti. In C. pipiens, an axon of presumed neurosecretory function was found associated with the neck region of the medial lobe.Complete development of the salivary glands occurs between the first and fifth days of adulthood. Morphological changes associated with blood-feeding were limited to the presence or absence of the salivary secretions in the apical cavities and duct lumen. During blood-feeding the contents of two of the glandular regions are voided, being replenished within 24 h Results are related to previous histochemical studies of the salivary glands of mosquitoes.

scholarly journals Overexpression of Activated AMPK in the Anopheles stephensi Midgut Impacts Mosquito Metabolism, Reproduction and Plasmodium Resistance

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 119
Author(s):  
Chioma Oringanje ◽  
Lillian R. Delacruz ◽  
Yunan Han ◽  
Shirley Luckhart ◽  
Michael A. Riehle
Keyword(s):  
Egg Production ◽  
Anopheles Stephensi ◽  
Mitochondrial Dynamics ◽  
Adult Life ◽  
Blood Feeding ◽  
Pathogen Resistance ◽  
Α Subunit ◽  
Significant Difference ◽  
Transgenic Lines ◽  
Ampk Activity

Mitochondrial integrity and homeostasis in the midgut are key factors controlling mosquito fitness and anti-pathogen resistance. Targeting genes that regulate mitochondrial dynamics represents a potential strategy for limiting mosquito-borne diseases. AMP-activated protein kinase (AMPK) is a key cellular energy sensor found in nearly all eukaryotic cells. When activated, AMPK inhibits anabolic pathways that consume ATP and activates catabolic processes that synthesize ATP. In this study, we overexpressed a truncated and constitutively active α-subunit of AMPK under the control of the midgut-specific carboxypeptidase promotor in the midgut of female Anopheles stephensi. As expected, AMPK overexpression in homozygous transgenic mosquitoes was associated with changes in nutrient storage and metabolism, decreasing glycogen levels at 24 h post-blood feeding when transgene expression was maximal, and concurrently increasing circulating trehalose at the same time point. When transgenic lines were challenged with Plasmodium falciparum, we observed a significant decrease in the prevalence and intensity of infection relative to wild type controls. Surprisingly, we did not observe a significant difference in the survival of adult mosquitoes fed either sugar only or both sugar and bloodmeals throughout adult life. This may be due to the limited period that the transgene was activated before homeostasis was restored. However, we did observe a significant decrease in egg production, suggesting that manipulation of AMPK activity in the mosquito midgut resulted in the re-allocation of resources away from egg production. In summary, this work identifies midgut AMPK activity as an important regulator of metabolism, reproduction, and innate immunity in An. stephensi, a highly invasive and important malaria vector species.

Preparation, characterization and comparative toxicity of nanopermethrin against Anopheles stephensi and Culex pipiens

2021 ◽  
Author(s):  
Pedram Ebrahimnejhad ◽  
Seyed Hassan Nikookar ◽  
Mahmoud Fazeli‐Dinan ◽  
Seyed Payman Ziapour ◽  
Ali Farmoudeh ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Comparative Toxicity

scholarly journals Molecular Correlation between Larval, Deutonymph and Adult Stages of the Water Mite Arrenurus (Micruracarus) Novus

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 108
Author(s):  
Pedro María Alarcón-Elbal ◽  
Ricardo García-Jiménez ◽  
María Luisa Peláez ◽  
Jose Luis Horreo ◽  
Antonio G. Valdecasas
Keyword(s):  
Culex Pipiens ◽  
Adult Stage ◽  
Gravid Female ◽  
Morphological Characters ◽  
Species Level ◽  
Life Stages ◽  
Water Mite ◽  
Molecular Correlation ◽  
The Common ◽  
Morphological Transformations

The systematics of many groups of organisms has been based on the adult stage. Morphological transformations that occur during development from the embryonic to the adult stage make it difficult (or impossible) to identify a juvenile (larval) stage in some species. Hydrachnidia (Acari, Actinotrichida, which inhabit mainly continental waters) are characterized by three main active stages—larval, deutonymph and adult—with intermediate dormant stages. Deutonymphs and adults may be identified through diagnostic morphological characters. Larvae that have not been tracked directly from a gravid female are difficult to identify to the species level. In this work, we compared the morphology of five water mite larvae and obtained the molecular sequences of that found on a pupa of the common mosquito Culex (Culex) pipiens with the sequences of 51 adults diagnosed as Arrenurus species and identified the undescribed larvae as Arrenurus (Micruracarus) novus. Further corroborating this finding, adult A. novus was found thriving in the same mosquito habitat. We established the identity of adult and deutonymph A. novus by morphology and by correlating COI and cytB sequences of the water mites at the larval, deutonymph and adult (both male and female) life stages in a particular case of ‘reverse taxonomy’. In addition, we constructed the Arrenuridae phylogeny based on mitochondrial DNA, which supports the idea that three Arrenurus subgenera are ‘natural’: Arrenurus, Megaluracarus and Micruracarus, and the somewhat arbitrary distinction of the species assigned to the subgenus Truncaturus.

scholarly journals MicroRNA-277 targetsinsulin-like peptides 7and8to control lipid metabolism and reproduction inAedes aegyptimosquitoes

2017 ◽  
Vol 114 (38) ◽  
pp. E8017-E8024 ◽  
Author(s):  
Lin Ling ◽  
Vladimir A. Kokoza ◽  
Changyu Zhang ◽  
Emre Aksoy ◽  
Alexander S. Raikhel
Keyword(s):  
Lipid Metabolism ◽  
Molecular Mechanisms ◽  
Fat Body ◽  
Critical Role ◽  
Target Prediction ◽  
Luciferase Reporter ◽  
Ovary Development ◽  
Mrna Levels ◽  
Essential Components ◽  
Energy Store

Hematophagous female mosquitoes transmit numerous devastating human diseases, including malaria, dengue fever, Zika virus, and others. Because of their obligatory requirement of a vertebrate blood meal for reproduction, these mosquitoes need a lot of energy; therefore, understanding the molecular mechanisms linking metabolism and reproduction is of particular importance. Lipids are the major energy store providing the fuel required for host seeking and reproduction. They are essential components of the fat body, a metabolic tissue that is the insect analog of vertebrate liver and adipose tissue. In this study, we found that microRNA-277 (miR-277) plays an important role in regulating mosquito lipid metabolism. The genetic disruption of miR-277 using the CRISPR-Cas9 system led to failures in both lipid storage and ovary development. miR-277 mimic injection partially rescued these phenotypic manifestations. Examination of subcellular localization of FOXO protein via CRISPR-assisted, single-stranded oligodeoxynucleotide-mediated homology-directed repair revealed that insulin signaling is up-regulated in response to miR-277 depletion. In silico target prediction identified that insulin-like peptides 7 and 8 (ilp7andilp8) are putative targets of miR-277; RNA immunoprecipitation and a luciferase reporter assay confirmed thatilp7andilp8are direct targets of this miRNA. CRISPR-Cas9 depletion ofilp7andilp8led to metabolic and reproductive defects. These depletions identified differential actions of ILP7 and ILP8 in lipid homeostasis and ovarian development. Thus, miR-277 plays a critical role in mosquito lipid metabolism and reproduction by targetingilp7andilp8, and serves as a monitor to control ILP7 and ILP8 mRNA levels.

scholarly journals Salivary AsHPX12 influence pre-blood meal associated behavioral properties in the mosquito Anopheles stephensi

2020 ◽  
Author(s):  
Seena Kumari ◽  
Tanwee Das De ◽  
Charu Chauhan ◽  
Jyoti Rani ◽  
Sanjay Tevatiya ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Blood Meal ◽  
Anopheles Stephensi ◽  
Blood Feeding ◽  
Vital Role ◽  
Host Attraction ◽  
Altered Expression ◽  
Rnaseq Data ◽  
Transcriptional Modulation ◽  
Physiological Homeostasis

AbstractIn the adult female mosquito, successful blood meal acquisition is accomplished by salivary glands, which releases a cocktail of proteins to counteract vertebrate host’s immune-homeostasis. However, the biological relevance of many salivary proteins remains unknown. Here, we characterize a salivary specific Heme peroxidase family member HPX12, originally identified from Plasmodium vivax infected salivary RNAseq data of the mosquito Anopheles stephensi. We demonstrate that dsRNA silencing mediated mRNA depletion of salivary AsHPX12 (80-90%), causes enhanced host attraction but reduced blood-meal acquisition abilities, by increasing probing propensity (31%), as well as probing time (100–200s, P<0.0001) as compared to control (35-90s) mosquitoes group. Altered expression of the salivary secretory and antennal proteins may account for an unusual fast release of salivary cocktail proteins, but the slowing acquisition of blood meal, possibly due to salivary homeostasis disruption of AsHPX12 silenced mosquitoes. A parallel transcriptional modulation in response to blood feeding and P. vivax infection, further establish a possible functional correlation of AsHPX12 role in salivary immune-physiology and Plasmodium sporozoites survival/transmission. We propose that salivary HPX12 may have a vital role in the management of ‘pre- and post’-blood meal associated physiological-homeostasis and parasite transmission.Graphical abstractFigure 1:Schematic representation of mosquito’s blood meal acquisition and upshot on blood-feeding after silencing of salivary gland HPX-12. (A) After landing over host skin, mosquito mouthparts (proboscis) actively engaged to search, probe, and pierce the skin followed by a rapid release of the pre-synthesized salivary cocktail, which counteracts the host homeostasis, inflammation, and immune responses, during blood meal uptake. (B) Silencing of HPX-12 disrupts salivary gland homeostasis, enhancing mosquito attraction, possibly by up-regulating odorant-binding proteins genes-OBP-7,10 and OBP-20 expression in the Olfactory System. However, HPX-12 disruption may also cause significant effects on pre-blood meal associated probing abilities, which may be due to fast down-regulation of salivary cocktail proteins such as Anopheline, Apyrase, D7L proteins.

Haemolymph Proteins and Yolk Formation in Rhodnius Prolixus Stål

1965 ◽  
Vol 43 (3) ◽  
pp. 425-431
Author(s):  
G. C. COLES
Keyword(s):  
Cellulose Acetate ◽  
Total Protein ◽  
Egg Production ◽  
Fat Body ◽  
Rhodnius Prolixus ◽  
Hormonal Control ◽  
Protein Fractions ◽  
Yolk Formation ◽  
Specific Proteins

1. There are two adult-specific proteins in the haemolymph of Rhodnius. They appear to be formed in the fat body. 2. The two proteins are absorbed by the oocytes and form the bulk of the soluble egg proteins. 3. The changes in the concentration of total protein in the haemolymph and of four protein fractions, as separated on cellulose acetate, do not reflect egg production. This may be a consequence of the hormonal control of reproduction.

The effect of parasitism by a blood-feeding isopod on the otolith chemistry of host fish

2013 ◽  
Vol 64 (1) ◽  
pp. 10 ◽  
Author(s):  
Elizabeth C. Heagney ◽  
Bronwyn M. Gillanders ◽  
Iain M. Suthers
Keyword(s):  
Mass Spectrometry ◽  
Physiological Mechanism ◽  
Blood Feeding ◽  
Population Based ◽  
Otolith Chemistry ◽  
Host Fish ◽  
Fish Stocks ◽  
Eastern Australia ◽  
Growth Bands ◽  
Plasma Mass Spectrometry

Otolith chemistry is widely used to discriminate fish stocks or populations, although many of the factors that determine trace-element concentrations within the otolith remain poorly understood. We investigated the effect of a blood-feeding isopod ectoparasite, Ceratothoa sp., on the otolith chemistry of yellowtail scad, Trachurus novaezelandiae. We sampled 65 fish from three subpopulations of T. novaezelandiae from Jervis Bay in south-eastern Australia, and used laser ablation (LA)–inductivelycoupled plasma mass spectrometry (ICPMS) to measure otolith lithium (Li) : calcium (Ca), magnesium (Mg) : Ca, strontium (Sr) : Ca and barium (Ba) : Ca from four consecutive summer and winter growth bands. Otoliths of parasitised fish were characterised by significantly lower Li : Ca and Mg : Ca, and higher Sr : Ca, than those of unparasitised individuals from the same subpopulation. The consistency of trends in otolith chemistry across ablation points and among subpopulations suggests that there is a consistent physiological mechanism through which Ceratothoa parasites affect the otolith chemistry of infected individuals. It is likely that a range of physical, metabolic, chemical and behavioural processes act in concert to influence the otolith chemistry of parasitised fish. Given the ubiquitous distribution of parasites in the marine environment, differential rates of parasitism among fish stocks, populations or migratory contingents may be an important but unappreciated factor driving stock- or population-based differences in otolith chemistry.

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