Genome of Rhodnius prolixus, an insect vector of Chagas disease, reveals unique adaptations to hematophagy and parasite infection.

Proc Natl Acad Sci U S A
Authors
Keywords
Abstract

Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼ 702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect. Although immune-deficiency (IMD)-mediated immune responses were observed, R. prolixus putatively lacks key components of the IMD pathway, suggesting a reorganization of the canonical immune signaling network. Although both Toll and IMD effectors controlled intestinal microbiota, neither affected Trypanosoma cruzi, the causal agent of Chagas disease, implying the existence of evasion or tolerance mechanisms. R. prolixus has experienced an extensive loss of selenoprotein genes, with its repertoire reduced to only two proteins, one of which is a selenocysteine-based glutathione peroxidase, the first found in insects. The genome contained actively transcribed, horizontally transferred genes from Wolbachia sp., which showed evidence of codon use evolution toward the insect use pattern. Comparative protein analyses revealed many lineage-specific expansions and putative gene absences in R. prolixus, including tandem expansions of genes related to chemoreception, feeding, and digestion that possibly contributed to the evolution of a blood-feeding lifestyle. The genome assembly and these associated analyses provide critical information on the physiology and evolution of this important vector species and should be instrumental for the development of innovative disease control methods.

Year of Publication
2015
Journal
Proc Natl Acad Sci U S A
Volume
112
Issue
48
Pages
14936-41
Date Published
2015 Dec 01
ISSN
1091-6490
URL
DOI
10.1073/pnas.1506226112
PubMed ID
26627243
PubMed Central ID
PMC4672799
Links
Grant list
NHGRI-HG003079 / PHS HHS / United States
HHSN272200900039C / PHS HHS / United States
R01 AI045545 / AI / NIAID NIH HHS / United States
HHSN272200900039C / AI / NIAID NIH HHS / United States
U54 HG003079 / HG / NHGRI NIH HHS / United States