scholarly journals Development of a pan-neuronal genetic driver in Aedes aegypti mosquitoes

Author(s):  
Zhilei Zhao ◽  
David Tian ◽  
Carolyn S. McBride

AbstractThe mosquito Aedes aegypti is the primary worldwide vector of arboviruses that infect humans, including dengue, Zika, chikungunya, and yellow fever. Recent advances in transgenic technology have yielded important new insight into the biology of this disease vector. The early development of neurogenetic tools, in particular, is beginning to shed light on the neural basis of behaviors that allow Ae. aegypti to thrive in human environments and find and bite human hosts. Despite these advances, a pan-neuronal expression driver remains elusive. Pan-neuronal drivers give researchers genetic access to all neurons and thus provide a critical entry point for circuit dissection. Here, we describe our efforts to generate pan-neuronal drivers in Ae. aegypti via targeted knock-in of in-frame reporter constructs to the native coding sequence of broadly expressed neural genes with CRISPR/Cas9. Two of five attempts were successful, resulting in a Syt1:GCaMP6s strain that expresses synaptically-localized GCaMP in all neurons and a brp-T2A-QF2w driver strain that can be used to drive and amplify expression of any effector in all neurons via the Q binary system. We show that both manipulations broadly and uniformly label the nervous system and have only mild effects on behavior. We envision that these strains will facilitate neurobiological research in Ae. aegypti mosquitoes and provide documentation of both successful and failed manipulations as a roadmap for similar tool development in other non-model species.

2021 ◽  
Author(s):  
Gordana Rašić ◽  
Igor Filipović ◽  
Sean L Wu ◽  
Tomás M León ◽  
Jared B Bennett ◽  
...  

AbstractA rare example of a successful long-term elimination of the mosquito Aedes aegypti is in Brisbane, Queensland, where the legislatively-enforced removal of rainwater tanks drove its disappearance by the mid-1950s. However, a decade-long drought led to the mass installation of rainwater tanks throughout the region, re-introducing critical breeding sites for the mosquito’s persistence in this subtropical region. With Ae. aegypti re-invading towns just 150 km north of Brisbane, we examined the potential for their sustained elimination. Through genomic analyses, we estimated historical expansion and current isolation between neighboring populations as close as 15 kilometers. The estimated recent migration rate, entomological and meteorological data were used to calibrate the simulations of elimination campaigns in the two southernmost populations. Our simulations indicate that Ae. aegypti could be eliminated with moderate release numbers of incompatible Wolbachia-infected (IIT) males (sorted with an error rate ≤10-6) if non-compliant rainwater tanks are removed first. With this combined campaign, highly effective suppression (>99%) was predicted in both towns, and complete elimination was predicted in 35% of simulations in one town. Without tank removal, however, IIT led to a moderate suppression (61-93%) even with a 40:1 ratio of released IIT males to local males. Moreover, with a ratio of >20:1, Wolbachia establishment was predicted when the sorting error was >10-7. Our conservative estimates of intervention outcomes inform the planning of Ae. aegypti elimination in the region, and offer insight into the effective combinations of conventional and novel control tools, particularly for vulnerable mosquito populations at range margins.SignificanceAfter decades of range stagnation in Australia, the Aedes aegypti mosquito is expanding southward, approaching the most-densely-populated areas of Queensland. Using population genomics and simulation modeling of elimination campaigns, we show that Australia’s southernmost populations of this disease vector are genetically isolated and could be eliminated with moderate releases of incompatible Wolbachia-infected males if major larval breeding sites (non-compliant rainwater tanks) are removed first. The risk of Wolbachia establishment for this approach is low, and so is the risk of quick mosquito re-invasion. Our conservative estimates of intervention outcomes inform the planning of Ae. aegypti elimination in the region, and offer new insight into the benefits of combining conventional and novel control tools, particularly for mosquito populations at range margins.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Limb K. Hapairai ◽  
Keshava Mysore ◽  
Yingying Chen ◽  
Elizabeth I. Harper ◽  
Max P. Scheel ◽  
...  

2020 ◽  
Vol 29 (3S) ◽  
pp. 631-637
Author(s):  
Katja Lund ◽  
Rodrigo Ordoñez ◽  
Jens Bo Nielsen ◽  
Dorte Hammershøi

Purpose The aim of this study was to develop a tool to gain insight into the daily experiences of new hearing aid users and to shed light on aspects of aided performance that may not be unveiled through standard questionnaires. Method The tool is developed based on clinical observations, patient experiences, expert involvement, and existing validated hearing rehabilitation questionnaires. Results An online tool for collecting data related to hearing aid use was developed. The tool is based on 453 prefabricated sentences representing experiences within 13 categories related to hearing aid use. Conclusions The tool has the potential to reflect a wide range of individual experiences with hearing aid use, including auditory and nonauditory aspects. These experiences may hold important knowledge for both the patient and the professional in the hearing rehabilitation process.


2020 ◽  
pp. 128-138
Author(s):  
A. S. Bik-Bulatov

The article uses little known letters of M. Gorky, many of which were published for the first time in 1997, as well as findings of Samara-based experts in local history to shed light on the writer’s work as editor-in-chief of the Samarskaya Gazeta newspaper in 1895. The researcher introduces hitherto unstudied reminiscences of the journalist D. Linyov (Dalin) about this period, which reference a letter by Gorky, now lost. The paper details a newly discovered episode of Gorky’s professional biography as a journalist: it concerns his campaign against a Samara ‘she-wolf,’ the madam of a local brothel A. Neucheva. Linyov’s reminiscences turn out to be an important and interesting source, offering an insight into the daily grind of the young editor Gorky, providing new evidence of his excellent organizational skills, and describing his moral and social stance. The author presents his work in the context of a recently initiated broader discussion about the need to map out all Russian periodicals for the period until 1917, as well as all research devoted to individual publications.


Author(s):  
Pawan Kumar Jayaswal ◽  
Asheesh Shanker ◽  
Nagendra Kumar Singh

Actin and tubulin are cytoskeleton proteins, which are important components of the celland are conserved across species. Despite their crucial significance in cell motility and cell division the distribution and phylogeny of actin and tubulin genes across taxa is poorly understood. Here we used publicly available genomic data of 49 model species of plants, animals, fungi and Protista for further understanding the distribution of these genes among diverse eukaryotic species using rice as reference. The highest numbers of rice actin and tubulin gene homologs were present in plants followed by animals, fungi and Protista species, whereas ten actin and nine tubulin genes were conserved in all 49 species. Phylogenetic analysis of 19 actin and 18 tubulin genes clustered them into four major groups each. One each of the actin and tubulin gene clusters was conserved across eukaryotic species. Species trees based on the conserved actin and tubulin genes showed evolutionary relationship of 49 different taxa clustered into plants, animals, fungi and Protista. This study provides a phylogenetic insight into the evolution of actin and tubulin genes in diverse eukaryotic species.


2020 ◽  
Vol 8 (11) ◽  
pp. 1633
Author(s):  
Mohamed F. Abdallah ◽  
Kris Audenaert ◽  
Sarah De Saeger ◽  
Jos Houbraken

The aflatoxin type B and G producer Aspergillus novoparasiticus was described in 2012 and was firstly reported from sputum, hospital air (Brazil), and soil (Colombia). Later, several survey studies reported the occurrence of this species in different foods and other agricultural commodities from several countries worldwide. This short communication reports on an old fungal strain (CBS 108.30), isolated from Pseudococcus sacchari (grey sugarcane mealybug) from an Egyptian sugarcane field in (or before) 1930. This strain was initially identified as Aspergillus flavus; however, using the latest taxonomy schemes, the strain is, in fact, A. novoparasiticus. These data and previous reports indicate that A. novoparasiticus is strongly associated with sugarcane, and pre-harvest biocontrol approaches with non-toxigenic A. novoparasiticus strains are likely to be more successful than those using non-toxigenic A. flavus strains. Further studies on the association between A. novoparasiticus and Pseudococcus sacchari might shed light on the distribution (and aflatoxin contamination) of this species in sugarcane. Additionally, the interaction between A. novoparasiticus, Pseudococcus sacchari, and sugarcane crop under different scenarios of climate change will be critical in order to get more insight into the host–pathogen interaction and host resistance and propose appropriate prevention strategies to decrease mycotoxin contamination and crop loss due to A. novoparasiticus attack.


2021 ◽  
pp. 194-214
Author(s):  
D. V. Zakharov

The article is devoted to the epistolary legacy of Nelle Harper Lee, the author of the American cult classic To Kill a Mockingbird (1960). The researcher examines a collection of Nelle’s letters written from 1956 to 2009, provides a detailed list of sources and makes suggestions about the potential new discoveries that could shed light on the life of ‘America’s most reclusive author.’ This short study of ‘posthumous baggage,’ as Lee referred to her private correspondence, offers an insight into the interests of the author, who insisted on keeping her personal life to herself. The letters included in the study concern the writer’s relationship to her father Amasa Coleman Lee, on whom she based the character of Atticus Finch, her attitude to her own biography published by Charles Shields, and personal anxieties of her final years. The author also details Lee’s opinions of literature, from the 19th-c. classics to contemporary authors, and shows how much she valued communication with her numerous fans.


2021 ◽  
pp. 079160352110684
Author(s):  
Patti O’Malley

The multiracial family and the existence of mixed race children have come to be a regular feature of Irish familial life. Yet, nation-building discourses have promulgated notions of ethnic and religious homogeneity with Irish identity being racialised exclusively as white. Moreover, to date, there has been a dearth of academic scholarship related to racial mixedness in the Irish context. Through in-depth interviews, this paper sets out, therefore, to provide empirical insight into the lives of fifteen black (African) – white (Irish) mixed race young people (aged 4 to 18) with a particular focus on their experiences of racialised exclusion. Indeed, findings suggest that, as in other majority white national contexts, the black-white mixed race young people are racialised as black in the Irish public domain and as such, are positioned as ‘racialised outsiders’. In fact, their narrative accounts shed light on everyday encounters saturated by ‘us-them’ racial constructs based on phenotype. Thus, these young people, who are not fully recognised as mixed race Irish citizens, are effectively deprived of a space in which to articulate their belonging within the existing statist (i.e. inside/outside) framework.


2014 ◽  
Vol 47 (02) ◽  
pp. 468-476 ◽  
Author(s):  
Erin R. Graham ◽  
Charles R. Shipan ◽  
Craig Volden

ABSTRACTWhat factors inhibit or facilitate cross-subfield conversations in political science? This article draws on diffusion scholarship to gain insight into cross-subfield communication. Diffusion scholarship represents a case where such communication might be expected, given that similar diffusion processes are analyzed in American politics, comparative politics, and international relations. We identify nearly 800 journal articles published on diffusion within political science between 1958 and 2008. Using network analysis we investigate the degree to which three “common culprits”—terminology, methodological approach, and journal type—influence levels of integration. We find the highest levels of integration among scholars using similar terms to describe diffusion processes, sharing a methodological approach (especially in quantitative scholarship), and publishing in a common set of subfield journals. These findings shed light on when cross-subfield communication is likely to occur with ease and when barriers may prove prohibitive.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hannah J. MacLeod ◽  
George Dimopoulos ◽  
Sarah M. Short

The midgut microbiota of the yellow fever mosquito Aedes aegypti impacts pathogen susceptibility and transmission by this important vector species. However, factors influencing the composition and size of the microbiome in mosquitoes are poorly understood. We investigated the impact of larval diet abundance during development on the composition and size of the larval and adult microbiota by rearing Aedes aegypti under four larval food regimens, ranging from nutrient deprivation to nutrient excess. We assessed the persistent impacts of larval diet availability on the microbiota of the larval breeding water, larval mosquitoes, and adult mosquitoes under sugar and blood fed conditions using qPCR and high-throughput 16S amplicon sequencing to determine bacterial load and microbiota composition. Bacterial loads in breeding water increased with increasing larval diet. Larvae reared with the lowest diet abundance had significantly fewer bacteria than larvae from two higher diet treatments, but not from the highest diet abundance. Adults from the lowest diet abundance treatment had significantly fewer bacteria in their midguts compared to all higher diet abundance treatments. Larval diet amount also had a significant impact on microbiota composition, primarily within larval breeding water and larvae. Increasing diet correlated with increased relative levels of Enterobacteriaceae and Flavobacteriaceae and decreased relative levels of Sphingomonadaceae. Multiple individual OTUs were significantly impacted by diet including one mapping to the genus Cedecea, which increased with higher diet amounts. This was consistent across all sample types, including sugar fed and blood fed adults. Taken together, these data suggest that availability of diet during development can cause lasting shifts in the size and composition of the microbiota in the disease vector Aedes aegypti.


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