Transcriptional variation of sensory-related genes in natural populations of Aedes albopictus

Abstract

Background: The Asian tiger mosquito, Aedes albopictus, is a highly dangerous invasive vector of numerous medically important arboviruses including dengue, chikungunya and Zika. In four decades it has spread from tropical Southeast Asia to many parts of the world in both tropical and temperate climes. The rapid invasion process of this mosquito is supported by its high ecological and genetic plasticity across different life history traits. Our aim was to investigate whether wild populations, both native and adventive, also display transcriptional genetic variability for functions that may impact their biology, behaviour and ability to transmit arboviruses, such as sensory perception. Results: Antennal transcriptome data were derived from mosquitoes from a native population from Ban Rai, Thailand and from three adventive Mediterranean populations: Athens, Greece and Arco and Trento from Italy. Clear inter-population differential transcriptional activity was observed in different gene categories related to sound perception, olfaction and viral infection. The greatest differences were detected between the native Thai and the Mediterranean populations. The two Italian populations were the most similar. Nearly one million quality filtered SNP loci were identified. Conclusion: The ability to express this great inter-population transcriptional variability highlights, at the functional level, the remarkable genetic flexibility of this mosquito species. We can hypothesize that the differential expression of genes, including those involved in sensory perception, in different populations may enable Ae. albopictus to exploit different environments and hosts, thus contributing to its status as a global vector of arboviruses of public health importance. The large number of SNP loci present in these transcripts represents a useful addition to the arsenal of highresolution molecular markers and a resource that can be used to detect selective pressure and adaptive changes that may have occurred during the colonization process.

Physiological and molecular correlates of the screwworm fly attraction to wound and animal odors

“…The simplest explanation for the disparity between EAG responses and gene expression analysis is that the EAGs are only proximate summation of the individual olfactory receptor neuron (ORN) responses 51 , and do not faithfully reflect the response of all chemosensory genes. Recent evidence also suggests variation in the transcriptional profiles of the chemosensory genes in natural mosquito populations 52 . Another likely explanation for absence of any sex-based correlation between the transcriptional profiles (Fig.…”

A Novel Anphevirus in Aedes albopictus Mosquitoes Is Distributed Worldwide and Interacts with the Host RNA Interference Pathway

“…We further queried transcriptomes that are not deposited in NCBI. We found unannotated contigs matching AealbAV in a transcriptome from the Georgetown University [45] and an antennal transcriptome of wild mosquito populations [40], indicating AealbAV sequences went unnoticed in these transcriptomes likely due to its high divergence to known viral sequences.…”

“…Additionally, we took advantage of recently published sequencing libraries to expand the assessment of AealbAV in wild-caught mosquitoes collected in Italy, Greece and Thailand (BioProject: PRJNA602498, 2020) [40] as well as in Switzerland (SRA accession: SRP266553, 2020) [41]. We assembled full AealbAV genomes from these libraries except for the Greek sample in which AealbAV appears to be absent (Table 1, Table S1).…”

Olfactory systems across mosquito species

“…The genetic differences between the two subspecies are focused in the region of chromosome 1 where the AeOR4 gene locus is located (Rose et al 2020). Similarly, populations of Aedes albopictus, which have been moved to novel areas through human activity, show upregulation of OR100 and OR47-N2 compared with predominantly zoophilic populations from its native range (Gomulski et al 2020). Aedes aegypti homologs of these receptors are upregulated in anthropophilic Aedes aegypti aegypti, suggesting that increased sensitivity to human odors may play a role in adaptations to new environments.…”