Transcriptomic and functional analysis of the Anopheles gambiae salivary gland in relation to blood feeding.
BACKGROUND
The Anopheles gambiae salivary glands play a major role in malaria transmission and express a variety of bioactive components that facilitate blood-feeding by preventing platelet aggregation, blood clotting, vasodilatation, and inflammatory and other reactions at the probing site on the vertebrate host.


RESULTS
We have performed a global transcriptome analysis of the A. gambiae salivary gland response to blood-feeding, to identify candidate genes that are involved in hematophagy. A total of 4,978 genes were found to be transcribed in this tissue. A comparison of salivary gland transcriptomes prior to and after blood-feeding identified 52 and 41 transcripts that were significantly up-regulated and down-regulated, respectively. Ten genes were further selected to assess their role in the blood-feeding process using RNAi-mediated gene silencing methodology. Depletion of the salivary gland genes encoding D7L2, anophelin, peroxidase, the SG2 precursor, and a 5'nucleotidase gene significantly increased probing time of A. gambiae mosquitoes and thereby their capacity to blood-feed.


CONCLUSIONS
The salivary gland transcriptome comprises approximately 38% of the total mosquito transcriptome and a small proportion of it is dynamically changing already at two hours in response to blood feeding. A better understanding of the salivary gland transcriptome and its function can contribute to the development of pathogen transmission control strategies and the identification of medically relevant bioactive compounds.
W Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe Street, Baltimore, MD 21205-2179, USA.
Suchismita
S
Das
Andrea
A
Radtke
Young-Jun
YJ
Choi
Antonio M
AM
Mendes
Jesus G
JG
Valenzuela
George
G
Dimopoulos
D000818:Animals; D000852:Anopheles / Q000201:enzymology / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D001522:Behavior, Animal; D050260:Carbohydrate Metabolism / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics; D003599:Cytoskeleton / Q000235:genetics; D004063:Digestion / Q000235:genetics; D005247:Feeding Behavior; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D017344:Genes, Insect / Q000235:genetics; D007109:Immunity / Q000235:genetics; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D012469:Salivary Glands / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics
D019476:Insect Proteins