Improved reference genome of the arboviral vector Aedes albopictus

Abstract

Background: The Asian tiger mosquito Aedes albopictus is globally expanding and has become the main vector for human arboviruses in Europe. With limited antiviral drugs and vaccines available, vector control is the primary approach to prevent mosquito-borne diseases. A reliable and accurate DNA sequence of the Ae. albopictus genome is essential to develop new approaches that involve genetic manipulation of mosquitoes. Results: We use long-read sequencing methods and modern scaffolding techniques (PacBio, 10X, and Hi-C) to produce AalbF2, a dramatically improved assembly of the Ae. albopictus genome. AalbF2 reveals widespread viral insertions, novel microRNAs and piRNA clusters, the sex-determining locus, and new immunity genes, and enables genome-wide studies of geographically diverse Ae. albopictus populations and analyses of the developmental and stage-dependent network of expression data. Additionally, we build the first physical map for this species with 75% of the assembled genome anchored to the chromosomes. Conclusion: The AalbF2 genome assembly represents the most up-to-date collective knowledge of the Ae. albopictus genome. These resources represent a foundation to improve understanding of the adaptation potential and the epidemiological relevance of this species and foster the development of innovative control measures.

Competition between Usutu virus and West Nile virus during simultaneous and sequential infection of Culex pipiens mosquitoes

“…The ISV-induced exclusion of flaviviruses has also been observed in an in vitro study where mosquito cells previously infected with PCV were found less permissive to WNV and Murray Valley encephalitis virus (MVEV) [ 38 ]. Besides, the infection of ISV may cause the insertion of viral elements into the mosquito genome and these nonretroviral integrated RNA virus sequences (NIRVs) or endogenous viral elements (EVEs) are known to generate PIWI-Interacting RNAs which might regulate arbovirus replication [ 39 , 40 ]. Instead of competition, sequential exposure of two heterologous arboviruses, CHIKV and ZIKV to Ae.…”

Exploring Changes in the Microbiota of Aedes albopictus: Comparison Among Breeding Site Water, Larvae, and Adults

“…Water and eggs/larvae were then collected in sterile 50-ml Falcon tubes and transferred to the insectary of the University of Pavia, Italy. The collected water was divided into three aliquots and used as follows: (i) an aliquot of 200 ml was brought to the ZooPlant laboratory in Milano, Italy, to characterize its microbial composition (samples hereafter called W Start); (ii) 300 ml were aliquoted in two different pans (150 ml/pan) and daily monitored for natural larval hatching in the Pavia insectary (samples named CR); (iii) 600 ml were used to hatch eggs from the Foshan strain ( Chen et al, 2015 ; Palatini et al, 2020 ), after having verified the absence of wild eggs using a stereomicroscope. The Foshan strain is an established laboratory colony derived from wild mosquitoes from South-East China and reared in the Pavia insectary since 2013 ( Palatini et al, 2017 ).…”

Mosquito genomes are frequently invaded by transposable elements through horizontal transfer

“…All the mosquito genomes used in this study were obtained from VectorBase [ 64 ] and NCBI Assembly [ 65 ] as a result of many studies [ 22 , 25 – 29 , 43 , 66 – 72 ]. The GenBank accession codes and other features of the assemblies are listed in S1 Table .…”

“…All the mosquito genomes used in this study were obtained from VectorBase [64] and NCBI Assembly [65] as a result of many studies [22,[25][26][27][28][29]43,[66][67][68][69][70][71][72]. The GenBank accession codes and other features of the assemblies are listed in S1 Table. The Mitochondrial DNA (mtDNA) was assembled using the raw reads for some species on Mitobin version 1.9.1 [73].…”