scholarly journals Circadian regulation of light-evoked attraction/avoidance in day- vs. night-biting mosquitoes

2019 ◽  
Author(s):  
Lisa Soyeon Baik ◽  
Ceazar Nave ◽  
David D. Au ◽  
Tom Guda ◽  
Joshua A. Chevez ◽  
...  

AbstractMosquitoes pose widespread threats to humans and other animals as disease vectors. Day- vs. night-biting mosquitoes occupy distinct time-of-day niches and exhibit very different innate temporal attraction/avoidance behavioral responses to light, yet little is known about their circuit or molecular mechanisms. Day-biting diurnal mosquitoes Aedes aegypti are attracted to light during the day regardless of spectra. In contrast, night-biting nocturnal mosquitoes Anopheles coluzzii avoid short, but not long wavelength light. Attraction/avoidance behavioral responses to light in both species change with time-of-day and show distinct sex and circuit differences. The basis of diurnal versus nocturnal behavior is driven by clock timing, which cycle anti-phase between day-biting versus night-biting mosquito species. Disruption of the circadian molecular clock severely interferes with light-evoked attraction/avoidance behavior in mosquitoes. In summary, attraction/avoidance mosquito behaviors are circadian and light regulated, which may be applied towards species specific control of harmful mosquitoes.

2020 ◽  
Author(s):  
Ali Afify ◽  
Christopher John Potter

Abstract Background: The species-specific mode of action for DEET and many other mosquito repellents is often unclear. Confusion may arise for many reasons. First, the response of a single mosquito species is often used to represent all mosquito species. Second, behavioral studies usually test the effect of repellents on mosquito attraction towards human odorants, rather than their direct repulsive effect on mosquitoes. Third, the mosquito sensory neuron responses towards repellents are often not directly examined. Methods: Here, we used a close proximity response assay to test the direct repulsive effect of six mosquito repellents on Anopheles coluzzii , Aedes aegypti , and Culex quinquefasciatus mosquitoes. Additionally, we used this behavioral assay and calcium imaging recordings of antennae to test the response of An. coluzzii mosquitoes towards two human odorants (1-octen-3-ol and benzaldehyde) at different concentrations, and mixtures of the repellents lemongrass oil and p-menthane-3,8-diol (PMD) with DEET. Results: We found that An. coluzzii mosquitoes were repelled by lemongrass oil and PMD, while Ae. aegypti and Cx. Quinquefasciatus mosquitoes were repelled by lemongrass oil, PMD, eugenol, and DEET. In addition, we found that high concentrations of 1-octen-3-ol and benzaldehyde were repellent, and activated more olfactory receptor neurons on the An. coluzzii antenna than lower concentrations. Finally, we found that changes in olfactory responses to repellent mixtures reflected changes in repulsive behaviors. Conclusions: Our findings suggest that different species of mosquitoes have different behavioral responses to repellents. We further suggest that high-odor concentrations may recruit repellent-sensing neurons, or generally excite many olfactory neurons, yielding repellent behavioral responses. Finally, we show that DEET can decrease the neuronal and behavioral response of An. coluzzii mosquitoes towards PMD but not towards lemongrass oil. Overall, these studies can help inform mosquito repellent choice by species, guide decisions on effective repellent blends, and could ultimately identify the olfactory neurons and receptors in mosquitoes that mediate repellency.


2020 ◽  
Author(s):  
Ali Afify ◽  
Christopher John Potter

Abstract Background: The species-specific mode of action for DEET and many other mosquito repellents is often unclear. Confusion may arise for many reasons. First, the response of a single mosquito species is often used to represent all mosquito species. Second, behavioral studies usually test the effect of repellents on mosquito attraction towards human odorants, rather than their direct repulsive effect on mosquitoes. Third, the mosquito sensory neuron responses towards repellents are often not directly examined.Methods: Here, we used a close proximity response assay to test the direct repulsive effect of six mosquito repellents on Anopheles coluzzii, Aedes aegypti, and Culex quinquefasciatus mosquitoes. Additionally, we used this behavioral assay and calcium imaging recordings of antennae to test the response of An. coluzzii mosquitoes towards two human odorants (1-octen-3-ol and benzaldehyde) at different concentrations, and mixtures of the repellents lemongrass oil and p-menthane-3,8-diol (PMD) with DEET.Results: We found that An. coluzzii mosquitoes were repelled by lemongrass oil and PMD, while Ae. aegypti and Cx. Quinquefasciatus mosquitoes were repelled by lemongrass oil, PMD, eugenol, and DEET. In addition, we found that high concentrations of 1-octen-3-ol and benzaldehyde were repellent, and activated more olfactory receptor neurons on the An. coluzzii antenna than lower concentrations. Finally, we found that changes in olfactory responses to repellent mixtures reflected changes in repulsive behaviors.Conclusions: Our findings suggest that different species of mosquitoes have different behavioral responses to repellents. We further suggest that high-odor concentrations may recruit repellent-sensing neurons, or generally excite many olfactory neurons, yielding repellent behavioral responses. Finally, we show that DEET can decrease the neuronal and behavioral response of An. coluzzii mosquitoes towards PMD but not towards lemongrass oil. Overall, these studies can help inform mosquito repellent choice by species, guide decisions on effective repellent blends, and could ultimately identify the olfactory neurons and receptors in mosquitoes that mediate repellency.


2019 ◽  
Vol 34 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Lisa Soyeon Baik ◽  
Yocelyn Recinos ◽  
Joshua A. Chevez ◽  
David D. Au ◽  
Todd C. Holmes

Short-wavelength light guides many behaviors that are crucial for an insect’s survival. In Drosophila melanogaster, short-wavelength light induces both attraction and avoidance behaviors. How light cues evoke two opposite valences of behavioral responses remains unclear. Here, we comprehensively examine the effects of (1) light intensity, (2) timing of light (duration of exposure, circadian time of day), and (3) phototransduction mechanisms processing light information that determine avoidance versus attraction behavior assayed at high spatiotemporal resolution in Drosophila. External opsin-based photoreceptors signal for attraction behavior in response to low-intensity ultraviolet (UV) light. In contrast, the cell-autonomous neuronal photoreceptors, CRYPTOCHROME (CRY) and RHODOPSIN 7 (RH7), signal avoidance responses to high-intensity UV light. In addition to binary attraction versus avoidance behavioral responses to UV light, flies show distinct clock-dependent spatial preference within a light environment coded by different light input channels.


2020 ◽  
Author(s):  
Ali Afify ◽  
Christopher John Potter

Abstract Background The species-specific mode of action for DEET and many other mosquito repellents is often unclear. Confusion may arise for many reasons. First, the response of a single mosquito species is often used to represent all mosquito species. Second, behavioural studies usually test the effect of repellents on mosquito attraction towards human odorants, rather than their direct repulsive effect on mosquitoes. Third, the mosquito sensory neuron responses towards repellents are often not directly examined. Methods A close proximity response assay was used to test the direct repulsive effect of six mosquito repellents on Anopheles coluzzii, Aedes aegypti and Culex quinquefasciatus mosquitoes. Additionally, behavioural assay and calcium imaging recordings of antennae were used to test the response of An. coluzzii mosquitoes towards two human odorants (1-octen-3-ol and benzaldehyde) at different concentrations, and mixtures of the repellents lemongrass oil and p-menthane-3,8-diol (PMD) with DEET. Results An. coluzzii mosquitoes were repelled by lemongrass oil and PMD, while Ae. aegypti and Cx. quinquefasciatus mosquitoes were repelled by lemongrass oil, PMD, eugenol, and DEET. In addition, high concentrations of 1-octen-3-ol and benzaldehyde were repellent, and activated more olfactory receptor neurons on the An. coluzzii antennae than lower concentrations. Finally, changes in olfactory responses to repellent mixtures reflected changes in repulsive behaviours. Conclusions The findings described here suggest that different species of mosquitoes have different behavioural responses to repellents. The data further suggest that high-odour concentrations may recruit repellent-sensing neurons, or generally excite many olfactory neurons, yielding repellent behavioural responses. Finally, DEET can decrease the neuronal and behavioural response of An. coluzzii mosquitoes towards PMD but not towards lemongrass oil. Overall, these studies can help inform mosquito repellent choice by species, guide decisions on effective repellent blends, and could ultimately identify the olfactory neurons and receptors in mosquitoes that mediate repellency. Methods: Here, we used a close proximity response assay to test the direct repulsive effect of six mosquito repellents on Anopheles coluzzii , Aedes aegypti , and Culex quinquefasciatus mosquitoes. Additionally, we used this behavioral assay and calcium imaging recordings of antennae to test the response of An. coluzzii mosquitoes towards two human odorants (1-octen-3-ol and benzaldehyde) at different concentrations, and mixtures of the repellents lemongrass oil and p-menthane-3,8-diol (PMD) with DEET. Results: We found that An. coluzzii mosquitoes were repelled by lemongrass oil and PMD, while Ae. aegypti and Cx. Quinquefasciatus mosquitoes were repelled by lemongrass oil, PMD, eugenol, and DEET. In addition, we found that high concentrations of 1-octen-3-ol and benzaldehyde were repellent, and activated more olfactory receptor neurons on the An. coluzzii antenna than lower concentrations. Finally, we found that changes in olfactory responses to repellent mixtures reflected changes in repulsive behaviors. Conclusions: Our findings suggest that different species of mosquitoes have different behavioral responses to repellents. We further suggest that high-odor concentrations may recruit repellent-sensing neurons, or generally excite many olfactory neurons, yielding repellent behavioral responses. Finally, we show that DEET can decrease the neuronal and behavioral response of An. coluzzii mosquitoes towards PMD but not towards lemongrass oil. Overall, these studies can help inform mosquito repellent choice by species, guide decisions on effective repellent blends, and could ultimately identify the olfactory neurons and receptors in mosquitoes that mediate repellency.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 831
Author(s):  
Patrycja Burzyńska ◽  
Łukasz F. Sobala ◽  
Krzysztof Mikołajczyk ◽  
Marlena Jodłowska ◽  
Ewa Jaśkiewicz

Carbohydrates have long been known to mediate intracellular interactions, whether within one organism or between different organisms. Sialic acids (Sias) are carbohydrates that usually occupy the terminal positions in longer carbohydrate chains, which makes them common recognition targets mediating these interactions. In this review, we summarize the knowledge about animal disease-causing agents such as viruses, bacteria and protozoa (including the malaria parasite Plasmodium falciparum) in which Sias play a role in infection biology. While Sias may promote binding of, e.g., influenza viruses and SV40, they act as decoys for betacoronaviruses. The presence of two common forms of Sias, Neu5Ac and Neu5Gc, is species-specific, and in humans, the enzyme converting Neu5Ac to Neu5Gc (CMAH, CMP-Neu5Ac hydroxylase) is lost, most likely due to adaptation to pathogen regimes; we discuss the research about the influence of malaria on this trait. In addition, we present data suggesting the CMAH gene was probably present in the ancestor of animals, shedding light on its glycobiology. We predict that a better understanding of the role of Sias in disease vectors would lead to more effective clinical interventions.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ye Yu ◽  
Tao Wang ◽  
Xiufang Chen ◽  
Lidong Zhang ◽  
Yang Wang ◽  
...  

AbstractStrain modulation is crucial for heteroepitaxy such as GaN on foreign substrates. Here, the epitaxy of strain-relaxed GaN films on graphene/SiC substrates by metal-organic chemical vapor deposition is demonstrated. Graphene was directly prepared on SiC substrates by thermal decomposition. Its pre-treatment with nitrogen-plasma can introduce C–N dangling bonds, which provides nucleation sites for subsequent epitaxial growth. The scanning transmission electron microscopy measurements confirm that part of graphene surface was etched by nitrogen-plasma. We study the growth behavior on different areas of graphene surface after pre-treatment, and propose a growth model to explain the epitaxial growth mechanism of GaN films on graphene. Significantly, graphene is found to be effective to reduce the biaxial stress in GaN films and the strain relaxation improves indium-atom incorporation in InGaN/GaN multiple quantum wells (MQWs) active region, which results in the obvious red-shift of light-emitting wavelength of InGaN/GaN MQWs. This work opens up a new way for the fabrication of GaN-based long wavelength light-emitting diodes.


2009 ◽  
Vol 2009 ◽  
pp. 1-19 ◽  
Author(s):  
GongXin Yu

Chimpanzees and humans are closely related but differ in many deadly human diseases and other characteristics in physiology, anatomy, and pathology. In spite of decades of extensive research, crucial questions about the molecular mechanisms behind the differences are yet to be understood. Here I reportExonVar, a novel computational pipeline forExon-based human-chimpanzee comparativeVariant analysis. The objective is to comparatively analyze mutations specifically those that caused the frameshift and nonsense mutations and to assess their scale and potential impacts on human-chimpanzee divergence. Genomewide analysis of human and chimpanzee exons withExonVaridentified a number of species-specific, exon-disrupting mutations in chimpanzees but much fewer in humans. Many were found on genes involved in important biological processes such as T cell lineage development, the pathogenesis of inflammatory diseases, and antigen induced cell death. A “less-is-more” model was previously established to illustrate the role of the gene inactivation and disruptions during human evolution. Here this analysis suggested a different model where the chimpanzee-specific exon-disrupting mutations may act as additional evolutionary force that drove the human-chimpanzee divergence. Finally, the analysis revealed a number of sequencing errors in the chimpanzee and human genome sequences and further illustrated that they could be corrected without resequencing.


Reproduction ◽  
2006 ◽  
Vol 132 (2) ◽  
pp. 319-331 ◽  
Author(s):  
Stefan Bauersachs ◽  
Susanne E Ulbrich ◽  
Karin Gross ◽  
Susanne E M Schmidt ◽  
Heinrich H D Meyer ◽  
...  

The endometrium plays a central role among the reproductive tissues in the context of early embryo–maternal communication and pregnancy. This study investigated transcriptome profiles of endometrium samples from day 18 pregnant vs non-pregnant heifers to get insight into the molecular mechanisms involved in conditioning the endometrium for embryo attachment and implantation. Using a combination of subtracted cDNA libraries and cDNA array hybridisation, 109 mRNAs with at least twofold higher abundance in endometrium of pregnant animals and 70 mRNAs with higher levels in the control group were identified. Among the mRNAs with higher abundance in pregnant animals, at least 41 are already described as induced by interferons. In addition, transcript levels of many new candidate genes involved in the regulation of transcription, cell adhesion, modulation of the maternal immune system and endometrial remodelling were found to be increased. The different expression level was confirmed with real-time PCR for nine genes. Localisation of mRNA expression in the endometrium was shown byin situhybridisation forAGRN,LGALS3BP,LGALS9,USP18,PARP12andBST2. A comparison with similar studies in humans, mice, and revealed species-specific and common molecular markers of uterine receptivity.


Sign in / Sign up

Export Citation Format

Share Document