Characterization of Viral Communities Carried by Male and Female Aedes Mosquitos Collected in Houston

Abstract

Mosquitos are known vectors of many serious viral diseases, but little is known about the complete collection of viral strains that they might carry. This is because we have historically relied on culturing techniques to study microbial diversity, but the genomic era has shown us that there is much more out there than we initially suspected. In this work, we present a genomic approach to characterizing the viral populations carried by different species of mosquitos found in Houston. Specifically, we are using metagenomics – that is, sequencing the entire genetic material in a sample, followed by analyses by computational tools to identify each sequence obtained from the sample. We collected mosquitos from various locations in Houston and separated them by species and sex using morphological and genetic markers. Total DNA and RNA were purified from pooled samples in order to characterize both DNA and RNA viruses. RNA samples were converted to cDNA to facilitate sequencing and the combined DNA/cDNA libraries were sequenced using 454 technology. We used a modified BLAST workflow developed in‐house to analyze the sequences. Our first analysis shows viral sequences obtained for samples of male and female Aedes aegypti. While thousands of unknown sequences were obtained, our results show that we are also able to detect both DNA and RNA viral sequences in our samples. A total of 51 different species of viruses were identified in the female sample, and 40 different species were found in the male sample. Those of interest include West Nile and Dengue. Interestingly, the female sample carried more RNA viruses than the male sample, although further work will reveal if this finding is significant or an experimental artifact. We plan on further analyzing the sequence libraries obtained, with particular focus on the unknown sequences, many of which may be viral. We are also working on building new libraries from new samples of mosquitos, including other genera typically found in Houston, such as Culex. These analyses will help us better understand the viral collections carried by different mosquitos in our city.Support or Funding InformationU.S. DOE Hispanic‐Serving Institutions STEM Articulation Grant P031C110128, the University of St. Thomas Cullen‐Smith Endowed Chair in Biology, and the University of St. Thomas Committee for Student Research.