A deep insight into the sialotranscriptome of the mosquito, Psorophora albipes

Abstract

BackgroundPsorophora mosquitoes are exclusively found in the Americas and have been associated with transmission of encephalitis and West Nile fever viruses, among other arboviruses. Mosquito salivary glands represent the final route of differentiation and transmission of many parasites. They also secrete molecules with powerful pharmacologic actions that modulate host hemostasis, inflammation, and immune response. Here, we employed next generation sequencing and proteome approaches to investigate for the first time the salivary composition of a mosquito member of the Psorophora genus. We additionally discuss the evolutionary position of this mosquito genus into the Culicidae family by comparing the identity of its secreted salivary compounds to other mosquito salivary proteins identified so far.ResultsIllumina sequencing resulted in 13,535,229 sequence reads, which were assembled into 3,247 contigs. All families were classified according to their in silico-predicted function/ activity. Annotation of these sequences allowed classification of their products into 83 salivary protein families, twenty (24.39%) of which were confirmed by our subsequent proteome analysis. Two protein families were deorphanized from Aedes and one from Ochlerotatus, while four protein families were described as novel to Psorophora genus because they had no match with any other known mosquito salivary sequence. Several protein families described as exclusive to Culicines were present in Psorophora mosquitoes, while we did not identify any member of the protein families already known as unique to Anophelines. Also, the Psorophora salivary proteins had better identity to homologs in Aedes (69.23%), followed by Ochlerotatus (8.15%), Culex (6.52%), and Anopheles (4.66%), respectively.ConclusionsThis is the first sialome (from the Greek sialo = saliva) catalog of salivary proteins from a Psorophora mosquito, which may be useful for better understanding the lifecycle of this mosquito and the role of its salivary secretion in arboviral transmission.

Tissue- and time-dependent transcription in Ixodes ricinus salivary glands and midguts when blood feeding on the vertebrate host

“…Previous work in mosquitoes has indicated that genes encoding salivary proteins in hematophagous insects have higher numbers of polymorphisms and non-synonymous substitutions than other gene classes2829. Mapping the reads on the assembled contigs allowed us to determinate single nucleotide polymorphisms (SNPs) in the CDS.…”

A Systems Level Analysis Reveals Transcriptomic and Proteomic Complexity in Ixodes Ricinus Midgut and Salivary Glands During Early Attachment and Feeding

“…The 25,808 nonredundant set of CDS were mapped to a hyperlinked excel spreadsheet that charts these sequences to several database comparisons as well as the number of reads deriving from each of the 10 libraries (16,17) . These 25,808 CDS supported the subsequent quantitative proteome analysis.…”

De novo assembly and annotation of the salivary gland transcriptome of Rhipicephalus appendiculatus male and female ticks during blood feeding

“…Positive selection in salivary proteins involved in arthropod blood feeding has previously been reported for mosquitos (Arcà et al, 2014;Chagas et al, 2013) and ticks (Dai et al, 2012;Kotsyfakis et al, 2015). Constant adaptation to host immune evasion and co-evolution with hosts would drive rapid expansion and divergence in salivary protein families.…”