The role of vector population variation and climate in Zika virus transmission patterns in Africa: a modelling study.

Background: Zika virus (ZIKV) outbreaks have raised major global health concerns recently, yet reported outbreaks are rare in Africa, where ZIKV was first discovered. Recent studies on Aedes aegypti, the mosquito that transmits ZIKV, might explain this phenomenon. The Ae aegypti subspecies present in Africa shows lower preference for biting humans and reduced susceptibility to ZIKV infection compared with the subspecies distributed outside Africa.

Intra-species quantification reveals differences in activity and sleep levels in the yellow fever mosquito, Aedes aegypti.

Aedes aegypti is an important mosquito vector of human disease with a wide distribution across the globe. Climatic conditions and ecological pressure drive differences in the biology of several populations of this mosquito species, including blood-feeding behaviour and vector competence. However, no study has compared activity and/or sleep among different populations/lineages of Ae.

Olfactory receptor coexpression and co-option in the dengue mosquito.

The olfactory sensory neurons of vinegar flies and mice tend to express a single ligand-specific receptor. While this 'one neuron-one receptor' motif has long been expected to apply broadly across insects, recent evidence suggests it may not extend to mosquitoes. We sequenced and analyzed the transcriptomes of 46,000 neurons from antennae of the dengue mosquito to resolve all olfactory, thermosensory, and hygrosensory neuron subtypes and identify the receptors expressed therein.

Global genomics of unveils widespread and novel infectious viruses capable of triggering a small RNA response.

The mosquito is a prominent vector for arboviruses, but the breadth of mosquito viruses that infects this specie is not fully understood. In the broadest global survey to date of over 200 small RNA samples, we detected viral small interfering RNAs (siRNAs) and Piwi interacting RNAs (piRNAs) arising from mosquito viruses. We confirmed that most academic laboratory colonies of lack persisting viruses, yet two commercial strains were infected by a novel tombus-like virus.

Extensive variation and strain-specificity in dengue virus susceptibility among African Aedes aegypti populations.

African populations of the mosquito Aedes aegypti are usually considered less susceptible to infection by human-pathogenic flaviviruses than globally invasive populations found outside Africa. Although this contrast has been well documented for Zika virus (ZIKV), it is unclear to what extent it is true for dengue virus (DENV), the most prevalent flavivirus of humans. Addressing this question is complicated by substantial genetic diversity among DENV strains, most notably in the form of four genetic types (DENV1 to DENV4), that can lead to genetically specific interactions with mosquito populations.

The chromosome-scale genome assembly for the West Nile vector Culex quinquefasciatus uncovers patterns of genome evolution in mosquitoes.

Background: Understanding genome organization and evolution is important for species involved in transmission of human diseases, such as mosquitoes. Anophelinae and Culicinae subfamilies of mosquitoes show striking differences in genome sizes, sex chromosome arrangements, behavior, and ability to transmit pathogens. However, the genomic basis of these differences is not fully understood.

Extensive variation and strain-specificity in dengue virus susceptibility among African populations.

African populations of the mosquito are usually considered less susceptible to infection by human-pathogenic flaviviruses than globally invasive populations found outside Africa. Although this contrast has been well documented for Zika virus (ZIKV), it is unclear to what extent it is true for dengue virus (DENV), the most prevalent flavivirus of humans. Addressing this question is complicated by substantial genetic diversity among DENV strains, most notably in the form of four genetic types (DENV1 to DENV4), that can lead to genetically specific interactions with mosquito populations.

Mosquito Larvae and Pupae Transport from the Field.

Laboratory study of field-collected mosquitoes can allow researchers to better understand the ways variation within and among mosquito populations shapes burdens of mosquito-borne disease. The complex comprises the most important vectors of malaria, but it can be challenging to keep in the laboratory. For some species of mosquitoes, especially , it is very difficult to bring viable eggs into the laboratory.

Collecting, Storing, and Hatching Eggs.

Laboratory study of natural populations of mosquitoes can play a key role in determining the underlying causes of variation in burdens of mosquito-borne disease. is the main vector of the viruses that cause dengue, chikungunya, Zika, and yellow fever, making it a high priority for laboratory study. eggs provide an ideal starting point for new laboratory colonies.

Dating the origin and spread of specialization on human hosts in mosquitoes.

The globally invasive mosquito subspecies is an effective vector of human arboviruses, in part because it specializes in biting humans and breeding in human habitats. Recent work suggests that specialization first arose as an adaptation to long, hot dry seasons in the West African Sahel, where relies on human-stored water for breeding. Here, we use whole-genome cross-coalescent analysis to date the emergence of human-specialist populationsand thus further probe the climate hypothesis.

Larval sites of the mosquito in forest and domestic habitats in Africa and the potential association with oviposition evolution.

Adaptations to anthropogenic domestic habitats contribute to the success of the mosquito as a major global vector of several arboviral diseases. The species inhabited African forests before expanding into domestic habitats and spreading to other continents. Despite a well-studied evolutionary history, how this species initially moved into human settlements in Africa remains unclear.

Improved reference genome of Aedes aegypti informs arbovirus vector control.

Female Aedes aegypti mosquitoes infect more than 400 million people each year with dangerous viral pathogens including dengue, yellow fever, Zika and chikungunya. Progress in understanding the biology of mosquitoes and developing the tools to fight them has been slowed by the lack of a high-quality genome assembly. Here we combine diverse technologies to produce the markedly improved, fully re-annotated AaegL5 genome assembly, and demonstrate how it accelerates mosquito science.

Polygenic evolution drives species divergence and climate adaptation in corals.

Closely related species often show substantial differences in ecological traits that allow them to occupy different environmental niches. For few of these systems is it clear what the genomic basis of adaptation is and whether a few loci of major effect or many genome-wide differences drive species divergence. Four cryptic species of the tabletop coral Acropora hyacinthus are broadly sympatric in American Samoa; here we show that two common species have differences in key environmental traits such as microhabitat distributions and thermal stress tolerance.

Early Transcriptional Responses during Heat Stress in the Coral Acropora hyacinthus.

Corals respond to heat pulses that cause bleaching with massive transcriptional change, but the immediate responses to stress that lead up to these shifts have never been detailed. Understanding these early signals could be important for identifying the regulatory mechanisms responsible for bleaching and how these mechanisms vary between more and less resilient corals. Using RNA sequencing (RNAseq) and sampling every 30 minutes during a short-term heat shock, we found that components of the transcriptome were significantly upregulated within 90 min and after a temperature increase of +2 °C.