Studies on the responses of the female Aedes mosquito. IX.—The mode of attractiveness of lysine and other amino-acids

1964 ◽  
Vol 54 (4) ◽  
pp. 675-687 ◽  
Author(s):  
E. Y. Lipsitz ◽  
A. W. A. Brown
Keyword(s):  
Amino Acids ◽  
Aedes Aegypti ◽  
Aedes Mosquito ◽  
Free Base ◽  
Direct Proportion ◽  
Ability To Act ◽  
Solvent Control

Of 26 amino-acids tested against a solvent control for their attractiveness to females of Aedes aegypti (L.), lysine was the most attractive and six others (threonine, 1-methylhistidine, arginine, tyrosine, glutamine and alanine) were significantly attractive; nine amino-acids were significantly repellent. Lysine converted to the monopicrate, then to the dihydrochloride and then back to the free base was attractive. The degree of attractiveness of lysine was in direct proportion to the amount of uncombined CO2 it inevitably adsorbs. It is also proportional to the amount of carbamino CO2 combined in the molecule. Some commercial samples of lysine contain repellent principles removable by distillation. It is concluded that the attractiveness of lysine to A. aegypti is due to its ability to act as a vehicle for CO2, both adsorbed and in carbamino combination.

Studies on the responses of the female Aedes Mosquito. X.—Comparison of oestrogens and amino acids as attractants

1964 ◽  
Vol 55 (3) ◽  
pp. 395-403 ◽  
Author(s):  
P. Roessler ◽  
A. W. A. Brown
Keyword(s):  
Amino Acids ◽  
Aedes Aegypti ◽  
The Other ◽  
Aedes Mosquito ◽  
Free Flight ◽  
Flight Cage ◽  
Stimulation Of

The attractiveness of oestriol and of a sample L-lysine to females of Aedes aegypti (L.) was tested (a) in an olfactometer of the Wieting-Hoskins type, and (b) in a free-flight cage enclosed in glass. Similar results were given by both methods, L-lysine being the more attractive at higher concentrations, but oestriol retaining its attractiveness down to much lower concentrations. When 27 L-amino acids were tested in the free-flight cage, 16 showed significantly positive stimulation. Of these lysine was the most attractive, representing a group of 11 which carried CO2 in carbaminoyl or adsorbed form or in both; the other five, of which tyrosine was the most attractive, carried no CO2.

Studies on the Responses of the Female Aëdes Mosquito. Part II.—The Action of Liquid Repellent Compounds

1951 ◽  
Vol 42 (1) ◽  
pp. 115-122 ◽  
Author(s):  
D. S. Sarkaria ◽  
A. W. A. Brown
Keyword(s):  
Aedes Aegypti ◽  
Volatile Compounds ◽  
Vapour Pressure ◽  
Aedes Mosquito ◽  
Large Cage ◽  
Mosquito Repellents ◽  
Protection Period

A number of liquid mosquito repellents were assessed for vapour repellency power in an olfactometer mounted in a very large cage filled with females of Aëdes aegypti. They were also tested for their knockdown power in fumigation bottles. Their vapour pressures were determined by the Ramsay-Young method.All the liquids showed vapour repellency, and in 39 out of the 42 tested this effect was highly significant. The highest vapour repellency ratings were shown by compounds already known to be the most effective repellents.Although the more volatile compounds such as citronellal tend to show the highest repellency ratings, nevertheless compounds of low vapour pressure such as indalone, DMP and isobornyl morpholinoacetate may also show high vapour repellency. It is concluded that vapour repellency, although in the first instance dependent upon volatility, can vary independently of vapour pressure, so that compounds may be found which afford not only a long protection period due to their nonvolatility, but also a high vapour repellency due to the potency of the comparatively few molecules that are volatilised.The vapours of most of the repellents were found to induce knockdown of mosquitos, but there was no correlation between the speed of this process and the vapour repellency of the compounds.

Transition Metal‐Free, Base‐Induced Arylation of Amino Acids: Synthesis of N ‐( para ‐Substituted phenyl)amino‐2‐carboxylic acids

2020 ◽  
Vol 5 (28) ◽  
pp. 8644-8648 ◽  
Author(s):  
Adejoke D. Osinubi ◽  
Josephat U. Izunobi ◽  
Olayinka T. Asekun ◽  
Oluwole B. Familoni ◽  
Xiaoguang Bao
Keyword(s):  
Amino Acids ◽  
Transition Metal ◽  
Carboxylic Acids ◽  
Free Base ◽  
Metal Free

Ontogenetic development of monosaccharide and amino acid transporters in rabbit intestine

1990 ◽  
Vol 259 (4) ◽  
pp. G544-G555 ◽  
Author(s):  
R. K. Buddington ◽  
J. M. Diamond
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Metabolic Rate ◽  
Direct Proportion ◽  
Natural Diet ◽  
Sugar Absorption ◽  
Age Related ◽  
Rabbit Intestine ◽  
Small Intestinal ◽  
Rabbit Milk

We measured brush-border uptakes of seven sugars and amino acids by rabbit intestine as a function of age from the day of birth to adulthood. Gut dimensions, especially those of the colon and cecum, increase more rapidly with body weight than would be true if rabbits maintained identical proportions as they grew. However, nominal small intestinal area increases in approximately direct proportion to the animal's basal metabolic rate. For all solutes except fructose, uptake per milligram of intestinal tissue is maximal at or near birth and declines to a level 2.5-5 times lower in the adult. Because of small intestinal growth, though, the total uptake capacity of the whole length of the small intestine increases in approximately direct proportion to metabolic rate. Fructose uptake per milligram is unique in increasing steeply at the time of weaning, correlated with the post-weaning first appearance of fructose in the natural diet. Age-related changes in uptake ratios among aldohexoses or amino acids suggest developmental sequences of related transporters. Correlated with the very high protein content of rabbit milk, the proline-to-glucose uptake ratio is higher in suckling rabbits than in other sucking mammals. Remarkably, the ratio for adult rabbits is higher than in other monogastric herbivores and is instead similar to values for carnivores. In explanation, although the transport capacity of the small intestine appears to account for proline absorption in rabbits of all ages and for sugar absorption in suckling rabbits, the hindgut may be a major site of carbohydrate digestion in adult rabbits.

scholarly journals On the use of inhibitors of 4-hydroxyphenylpyruvate dioxygenase as a vector-selective insecticide in the control of mosquitoes

2019 ◽  
Author(s):  
Marlon A. V. Ramirez ◽  
Marcos Sterkel ◽  
Ademir de Jesus Martins ◽  
José Bento Pereira Lima ◽  
Pedro L. Oliveira
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Aedes Aegypti ◽  
Blood Meal ◽  
Mosquito Control ◽  
Blood Feeding ◽  
Degradation Pathway ◽  
Cross Resistance ◽  
Single Meal ◽  
Neurotoxic Insecticides

AbstractBlood-sucking insects incorporate many times their body weight of blood in a single meal. As proteins are the major component of vertebrate blood, its digestion in the gut of hematophagous insects generates extremely high concentrations of free amino acids. Previous reports showed that the tyrosine degradation pathway plays an essential role in adapting these animals to blood feeding. Inhibiting 4-hydroxyphenylpyruvate dioxygenase (HPPD), the rate-limiting step of tyrosine degradation, results in the death of insects after a blood meal. Therefore, it was suggested that compounds that block the catabolism of tyrosine could act selectively on blood-feeding insects. Here we have evaluated the toxicity against mosquitoes of three HPPD inhibitors currently used as herbicides and in human health. Among the compounds tested, nitisinone (NTBC) proved to be more potent than mesotrione (MES) and isoxaflutole (IFT) in Aedes aegypti. NTBC was lethal to Ae. aegypti in artificial feeding assays (LD50: 4.36 µM), as well as in topical application (LD50: 0.0033 nmol/mosquito). NTBC was also lethal to Ae. aegypti populations that were resistant to neurotoxic insecticides, and it was lethal to other mosquito species (Anopheles and Culex). Therefore, HPPD inhibitors, particularly NTBC, represent promising new drugs for mosquito control. Since they only affect blood-feeding organisms, they would represent a safer and more environmentally friendly alternative to conventional neurotoxic insecticides.Author SummaryThe control of mosquitoes has been pursued in the last decades by the use of neurotoxic insecticides to prevent the spreading of dengue, zika and malaria, among other diseases. However, the selection and propagation of different mechanisms of resistance hinder the success of these compounds. New methodologies are needed for their control. Hematophagous arthropods, including mosquitoes, ingest quantities of blood that represent many times their body weight in a single meal, releasing huge amounts of amino acids during digestion. Recent studies showed that inhibition of the tyrosine catabolism pathway could be a new selective target for vector control. Thus we tested three different inhibitors of the second enzyme in the tyrosine degradation pathway as tools for mosquito control. Results showed that Nitisinone (NTBC), an inhibitor used in medicine, was the most potent of them. NTBC was lethal to Aedes aegypti when it was administered together with the blood meal and when it was topically applied. It also caused the death of Anopheles aquasalis and Culex quinquefasciatus mosquitoes, as well as field-collected Aedes populations resistant to neurotoxic insecticides, indicating that there is no cross-resistance. We discuss the possible use of NTBC as a new insecticide.

scholarly journals Mutational analysis of Aedes aegypti Dicer 2 provides insights into the biogenesis of antiviral exogenous small interfering RNAs

2022 ◽  
Vol 18 (1) ◽  
pp. e1010202
Author(s):  
Rommel J. Gestuveo ◽  
Rhys Parry ◽  
Laura B. Dickson ◽  
Sebastian Lequime ◽  
Vattipally B. Sreenu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Antiviral Activity ◽  
Aedes Aegypti ◽  
Semliki Forest Virus ◽  
Mutational Analysis ◽  
Helicase Domain ◽  
Small Interfering Rnas ◽  
Rnase Iii ◽  
Argonaute 2 ◽  
Sirna Pathway

The exogenous small interfering RNA (exo-siRNA) pathway is a key antiviral mechanism in the Aedes aegypti mosquito, a widely distributed vector of human-pathogenic arboviruses. This pathway is induced by virus-derived double-stranded RNAs (dsRNA) that are cleaved by the ribonuclease Dicer 2 (Dcr2) into predominantly 21 nucleotide (nt) virus-derived small interfering RNAs (vsiRNAs). These vsiRNAs are used by the effector protein Argonaute 2 within the RNA-induced silencing complex to cleave target viral RNA. Dcr2 contains several domains crucial for its activities, including helicase and RNase III domains. In Drosophila melanogaster Dcr2, the helicase domain has been associated with binding to dsRNA with blunt-ended termini and a processive siRNA production mechanism, while the platform-PAZ domains bind dsRNA with 3’ overhangs and subsequent distributive siRNA production. Here we analyzed the contributions of the helicase and RNase III domains in Ae. aegypti Dcr2 to antiviral activity and to the exo-siRNA pathway. Conserved amino acids in the helicase and RNase III domains were identified to investigate Dcr2 antiviral activity in an Ae. aegypti-derived Dcr2 knockout cell line by reporter assays and infection with mosquito-borne Semliki Forest virus (Togaviridae, Alphavirus). Functionally relevant amino acids were found to be conserved in haplotype Dcr2 sequences from field-derived Ae. aegypti across different continents. The helicase and RNase III domains were critical for silencing activity and 21 nt vsiRNA production, with RNase III domain activity alone determined to be insufficient for antiviral activity. Analysis of 21 nt vsiRNA sequences (produced by functional Dcr2) to assess the distribution and phasing along the viral genome revealed diverse yet highly consistent vsiRNA pools, with predominantly short or long sequence overlaps including 19 nt overlaps (the latter representing most likely true Dcr2 cleavage products). Combined with the importance of the Dcr2 helicase domain, this suggests that the majority of 21 nt vsiRNAs originate by processive cleavage. This study sheds new light on Ae. aegypti Dcr2 functions and properties in this important arbovirus vector species.

Molecular cloning, sequence analysis and developmental stage expression of a putative septin gene fragment from Aedes albopictus (Diptera: Culicidae).

2016 ◽  
Vol 63 (2) ◽  
Author(s):  
Silas W Avicor ◽  
Mustafa F F Wajidi ◽  
Zairi Jaal ◽  
Zary S Yahaya
Keyword(s):  
Amino Acids ◽  
Sequence Analysis ◽  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Culex Quinquefasciatus ◽  
Developmental Stages ◽  
Developmental Expression ◽  
Gene Fragment ◽  
Close Phylogenetic Relationship ◽  
First Time

Septins belong to GTPases that are involved in vital cellular activities, including cytokinesis. Although present in many organisms, they are yet to be isolated from Aedes albopictus. This study reports for the first time on a serendipitous isolation of a partial septin sequence from Ae. albopictus and its developmental expression profile. The Ae. albopictus partial septin sequence contains 591 nucleotides encoding 197 amino acids. It shares homology with several insect septin genes and has a close phylogenetic relationship with Aedes aegypti and Culex quinquefasciatus septins. The Ae. albopictus septin fragment was differentially expressed in the mosquito's developmental stages, with an increased expression in the adults.

Metabolic fate of [14C]-labeled meal protein amino acids in Aedes aegypti mosquitoes

2004 ◽  
Vol 50 (4) ◽  
pp. 337-349 ◽  
Author(s):  
Guoli Zhou ◽  
Matthew Flowers ◽  
Kenneth Friedrich ◽  
James Horton ◽  
James Pennington ◽  
...  
Keyword(s):  
Amino Acids ◽  
Aedes Aegypti ◽  
Metabolic Fate ◽  
Meal Protein ◽  
Protein Amino Acids

scholarly journals Avoidance of the plant hormone cis-jasmone by Aedes aegypti depends on mosquito age in both plant and human odor backgrounds

2021 ◽  
Author(s):  
Jetske Gudrun de Boer ◽  
Aron P.S. Kuiper ◽  
Joeri Groot ◽  
Joop J.A. van Loon
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Species ◽  
Lima Bean ◽  
Olfactory Response ◽  
Metabolic Energy ◽  
Young Females ◽  
Olfactory Responses ◽  
Bean Plants ◽  
Human Odor ◽  
Solvent Control

Abstract Adults of many mosquito species feed on plants to obtain metabolic energy and to enhance reproduction. Mosquitoes primarily rely on olfaction to locate plants and are known to respond to a range of plant volatiles. We studied the olfactory response of the yellow fever mosquito Aedes aegypti to methyl jasmonate (MeJA) and cis-jasmone (CiJA), volatile compounds originating from the octadecanoid signaling pathway that plays a key role in plant defense against herbivores. Specifically, we investigated how Ae. aegypti of different ages responded to elevated levels of CiJA in two attractive odor contexts, either derived from Lima bean plants or from human skin. Aedes aegypti females landed significantly less often on a surface with CiJA and MeJA compared to the solvent control, CiJA exerting a stronger reduction in landing than MeJA. Odor context (plant or human) had no significant main effect on the olfactory responses of Ae. aegypti females to CiJA. Mosquito age significantly affected the olfactory response, older females (7–9 d) responding more strongly to elevated levels of CiJA than young females (1–3 d) in either odor context. Our results show that avoidance of CiJA by Ae. aegypti is independent of odor background, suggesting that jasmonates are inherently aversive cues to these mosquitoes. We propose that avoidance of plants with elevated levels of jasmonates is adaptive to mosquitoes to reduce the risk of encountering predators that is higher on these plants, i.e. by avoiding ‘enemy-dense-space’.

Sign in / Sign up

Export Citation Format

Share Document