Positive selection drives accelerated evolution of mosquito salivary genes associated with blood-feeding.
The saliva of bloodsucking animals contains dozens to hundreds of proteins that counteract their hosts' haemostasis, inflammation and immunity. It was previously observed that salivary proteins involved in haematophagy are much more divergent in their primary sequence than those of housekeeping function, when comparisons were made between closely related organisms. While this pattern of evolution could result from relaxed selection or drift, it could alternatively be the result of positive selection driven by the intense pressure of the host immune system. We investigated the polymorphism of five different genes associated with blood-feeding in the mosquito Anopheles gambiae and obtained evidence in four genes for sites with signatures of positive selection. These results add salivary gland genes from bloodsucking arthropods to the small list of genes driven by positive selection.
Department of Public Health and Infectious Diseases, Parasitology Section, Sapienza University of Rome, Roma, Italy.
B
B
Arcà
C J
CJ
Struchiner
V M
VM
Pham
G
G
Sferra
F
F
Lombardo
M
M
Pombi
J M C
JM
Ribeiro
D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000235:genetics; D019143:Evolution, Molecular; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000235:genetics; D012469:Salivary Glands / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000096:biosynthesis*; D012641:Selection, Genetic
D019476:Insect Proteins; D012471:Salivary Proteins and Peptides
evolution; haematophagy; salivary glands