An updated catalogue of salivary gland transcripts in the adult female mosquito,Anopheles gambiae

Abstract

Salivary glands of blood-sucking arthropods contain a variety of compounds that prevent platelet and clotting functions and modify inflammatory and immunological reactions in the vertebrate host. In mosquitoes, only the adult female takes blood meals, while both sexes take sugar meals. With the recent description of the Anopheles gambiae genome, and with a set of ~3000 expressed sequence tags from a salivary gland cDNA library from adult female mosquitoes, we attempted a comprehensive description of the salivary transcriptome of this most important vector of malaria transmission. In addition to many transcripts associated with housekeeping functions, we found an active transposable element, a set of Wolbachia-like proteins, several transcription factors, including Forkhead, Hairy and doublesex, extracellular matrix components and 71·genes coding for putative secreted proteins. Fourteen of these 71·proteins had matching Edman degradation sequences obtained from SDS-PAGE experiments. Overall, 33·transcripts are reported for the first time as coding for salivary proteins. The tissue and sex specificity of these protein-coding transcripts were analyzed by RT-PCR and microarray experiments for insight into their possible function. Notably, two gene products appeared to be differentially spliced in the adult female salivary glands, whereas 13·contigs matched predicted intronic regions and may include additional alternatively spliced transcripts. Most An. gambiae salivary proteins represent novel protein families of unknown function, potentially coding for pharmacologically or microbiologically active substances. Supplemental data to this work can be found at http:// www.ncbi.nlm.nih.gov/projects/omes/index.html#Ag2.

Identity and transfer of male reproductive gland proteins of the dengue vector mosquito, Aedes aegypti: Potential tools for control of female feeding and reproduction

“…aegypti, calreticulins, fibrinogen/fibronectins, serpins, phosphatidylethanolamine-binding proteins, odorant-binding proteins, alkaline phosphatases, lectins, and hydrolases are expressed in both the male AG/ED and the female salivary glands (Valenzuela et al, 2002;. Genes encoding proteins in these classes are also expressed in the salivary glands and digestive tracts of other blood-feeding arthropods (Jaworski et al, 1995;Ribeiro et al, 2004;Arca et al, 2005;Andersen et al, 2007).…”

An insight into the sialotranscriptome of the non-blood feeding Toxorhynchites amboinensis mosquito

“…A good proportion of these transcripts could have derived from truncated 3 / or 5 / untranslated regions of genes of the above two categories, as was recently indicated for a sialotranscriptome of An. gambiae (Arca et al, 2005). Probable transposable elements originated one singleton representing either active transposition or, more likely, expression of transposable element regulatory transcripts in Tx.…”

“…Recent sialotranscriptome analysis of adult female mosquitoes has uncovered a putative cocktail of SG-secreted polypeptides numbering near 70 gene products Arca et al, 2005;Calvo et al, 2007a;Ribeiro et al, 2007). For most of these putative secreted polypeptides, no functional assignment is possible based on their primary sequence.…”

“…For most of these putative secreted polypeptides, no functional assignment is possible based on their primary sequence. Many of these proteins are unique to mosquitoes, and some are unique to either Culicines or Anophelines (Arca et al, 2005;Calvo et al, 2004;Ribeiro et al, 2004b;Valenzuela et al, 2003). In an attempt to separate secreted salivary gene products into those assisting either blood or sugar feeding, quantitative polymerase chain reaction (PCR) or DNA microarray analysis of different tissues and sexes have been attempted for Anopheles gambiae (Arca et al, 2005), AEdes aegypti , and AEdes albopictus , as well as a comparative analysis of male and female sialotranscriptomes, in the case of An.…”

The enhancement of arbovirus transmission and disease by mosquito saliva is associated with modulation of the host immune response

“…Mosquitoes, like all haematophagous arthropods, have evolved mechanisms to effectively neutralize host haemostatic responses, based upon the release of saliva into the feeding site. Saliva is a pharmacologic cocktail of secreted molecules, principally proteins, that can affect vascular constriction, blood coagulation, platelet aggregation, inflammation, immunity, and angiogenesis (Arca et al 1999, Arca et al 2002, Arca et al 2005, Billingsley et al 2006, Calvo et al 2004, Calvo et al 2006a, Calvo et al 2006b, Calvo and Ribeiro 2006, Champagne 2004, Champagne et al 1995, Cross et al 1994, James et al 1991, Kerlin and Hughes 1992, Mellink and Vos 1977, Ribeiro 1987, 1989b, 1992, Ribeiro et al 2000, Ribeiro and Francischetti 2001, 2003, Ribeiro and Nussenzveig 1993, Ribeiro et al 1994, Stark and James 1998, Suwan et al 2002, Valenzuela et al 2002, Wanasen et al 2004, Wasserman et al 2004, Zeidner et al 1999. The saliva of all species of haematophagous arthropod analyzed to date contains at least one anticlotting, one anti-platelet, and one vasodilatory substance.…”