A Deep Insight into the Sialome of Male and Female Aedes aegypti Mosquitoes

PLoS One. 2016 Mar 21;11(3):e0151400. doi: 10.1371/journal.pone.0151400. eCollection 2016.

Abstract

Only adult female mosquitoes feed on blood, while both genders take sugar meals. Accordingly, several compounds associated with blood feeding (i.e. vasodilators, anti-clotting, anti-platelets) are found only in female glands, while enzymes associated with sugar feeding or antimicrobials (such as lysozyme) are found in the glands of both sexes. We performed de novo assembly of reads from adult Aedes aegypti female and male salivary gland libraries (285 and 90 million reads, respectively). By mapping back the reads to the assembled contigs, plus mapping the reads from a publicly available Ae. aegypti library from adult whole bodies, we identified 360 transcripts (including splice variants and alleles) overexpressed tenfold or more in the glands when compared to whole bodies. Moreover, among these, 207 were overexpressed fivefold or more in female vs. male salivary glands, 85 were near equally expressed and 68 were overexpressed in male glands. We call in particular the attention to C-type lectins, angiopoietins, female-specific Antigen 5, the 9.7 kDa, 12-14 kDa, 23.5 kDa, 62/34 kDa, 4.2 kDa, proline-rich peptide, SG8, 8.7 kDa family and SGS fragments: these polypeptides are all of unknown function, but due to their overexpression in female salivary glands and putative secretory nature they are expected to affect host physiology. We have also found many transposons (some of which novel) and several endogenous viral transcripts (probably acquired by horizontal transfer) which are overexpressed in the salivary glands and may play some role in tissue-specific gene regulation or represent a mechanism of virus interference. This work contributes to a near definitive catalog of male and female salivary gland transcripts from Ae. aegypti, which will help to direct further studies aiming at the functional characterization of the many transcripts with unknown function and the understanding of their role in vector-host interaction and pathogen transmission.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / genetics*
  • Animals
  • Female
  • Gene Expression Profiling
  • Male
  • Organ Specificity / genetics
  • Polymerase Chain Reaction
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Real-Time Polymerase Chain Reaction
  • Reproducibility of Results
  • Salivary Glands / metabolism*
  • Sequence Analysis, RNA
  • Sex Characteristics
  • Transcriptome / genetics*
  • Up-Regulation / genetics

Substances

  • RNA, Messenger

Grants and funding

BA was supported by funds from the EU grant INFRAVEC (228421) and from MIUR (PRIN 2010-2011, SKINFLAM, 2010C2LKKJ_004); EC, IMM and JMCR by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA.