Format

Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2014 May 13;111(19):6946-51. doi: 10.1073/pnas.1404179111. Epub 2014 Apr 28.

Collagen-binding protein, Aegyptin, regulates probing time and blood feeding success in the dengue vector mosquito, Aedes aegypti.

Author information

1
Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD 20852;
2
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900; and.
3
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900; andDepartment of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697-4025.
4
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900; and ecalvo@niaid.nih.gov omarinot@uci.edu.
5
Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD 20852; ecalvo@niaid.nih.gov omarinot@uci.edu.

Abstract

Mosquito salivary glands have important roles in blood feeding and pathogen transmission. However, the biological relevance of many salivary components has yet to be determined. Aegyptin, a secreted salivary protein from Aedes aegypti, binds collagen and inhibits platelet aggregation and adhesion. We used a transgenic approach to study the relevance of Aegyptin in mosquito blood feeding. Aedes aegypti manipulated genetically to express gene-specific inverted-repeat RNA sequences exhibited significant reductions in Aegyptin mRNA accumulation (85-87%) and protein levels (>80-fold) in female mosquito salivary glands. Transgenic mosquitoes had longer probing times (78-300 s, P < 0.0001) when feeding on mice compared with controls (15-56 s), feeding success was reduced, and those feeding took smaller blood meals. However, no differences in feeding success or blood meal size were found in membrane feeding experiments using defibrinated human blood. Salivary gland extracts from transgenic mosquitoes failed to inhibit collagen-induced platelet aggregation in vitro. Reductions of Aegyptin did not affect salivary ADP-induced platelet aggregation inhibition or disturb anticlotting activities. Our results demonstrate the relevance of Aegyptin for A. aegypti blood feeding, providing further support for the hypothesis that platelet aggregation inhibition is a vital salivary function in blood feeding arthropods. It has been suggested that the multiple mosquito salivary components mediating platelet aggregation (i.e., Aegyptin, apyrase, D7) represent functional redundancy. Our findings do not support this hypothesis; instead, they indicate that multiple salivary components work synergistically and are necessary to achieve maximum blood feeding efficiency.

KEYWORDS:

RNAi; evolution; hematophagy; saliva; transgenesis

PMID:
24778255
PMCID:
PMC4024861
DOI:
10.1073/pnas.1404179111
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center