Metagenomics Analysis of Viral Families Carried by Aedes Mosquitos in Houston.

Mosquitos are known vectors of many serious viral diseases, but little is known about the complete collection of viral strains that they might carry. Historically, we have relied on culturing techniques to study microbial diversity, but genomic analyses have demonstrated that there is much more out there than initially suspected. In this study, we used a metagenomic approach to characterize the viral populations carried by different species of mosquitos found in Houston. Specifically, we sequenced the entire genetic material in pooled mosquito samples, followed by analyses with computational tools to identify each sequence obtained. We collected mosquitos from various locations in Houston and separated them by both species and sex using morphological characteristics and DNA barcoding. Total DNA and RNA were used 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 resulting sequences. Our first analysis involved samples of male and female Aedes aegypti.Our results showed that we are able to detect both DNA and RNA viral sequences in our samples, as well as thousands of unknown or novel sequences. A total of 51 different species of viruses were identified in the female sample, and 40 different species in the male sample. Those of interest include West Nile and Dengue, as well as lesser known viruses, like Nam Dinh. 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. Currently, we are in the process of building libraries from new samples of mosquitos, including other species typically found in our area, such as Culexand Anopheles. We plan on further analyzing the sequence libraries obtained, with particular focus on the unknown sequences, many of which may be viral in origin. These studies will help us better understand the viral collections carried by different mosquitos in the Greater Houston area.