Publications by authors named "William Bart Bryant"

3 Publications

  • Page 1 of 1

Infection of mosquitoes with midgut-attenuated Sindbis virus reduces, but does not eliminate, disseminated infection.

J Virol 2021 Apr 14. Epub 2021 Apr 14.

Division of Biology, Kansas State University, Manhattan, Kansas 66503

Arboviruses are transmitted by specific vectors and the reasons for this specificity are not fully understood. One contributing factor is the existence of tissue barriers within the vector such as the midgut escape barrier. We used miRNA targeting of Sindbis virus (SINV) to study how replication in midgut cells contributes to overcoming this barrier in the mosquito SINV constructs were designed to be attenuated specifically in midgut cells by inserting binding sites for midgut-specific miRNAs into either the 3' untranslated region (MRE3'miRT) or the structural open reading frame (MRE-ORFmiRT) of the SINV genome. Both miRNA-targeted viruses replicated less efficiently than control viruses in the presence of these miRNAs. When mosquitoes were given infectious blood meals containing miRNA-targeted viruses, only around 20% (MRE3'miRT) or 40% (MRE-ORFmiRT) of mosquitoes developed disseminated infection. In contrast, dissemination occurred in almost all mosquitoes fed control viruses. Deep sequencing of virus populations from individual mosquitoes ruled out selection for mutations in the inserted target sequences as being the cause for dissemination in these mosquitoes. In mosquitoes that became infected with miRNA-targeted viruses, titers were equivalent to control virus in both the midgut and the carcass and there was no evidence of a threshold titer necessary for dissemination. Instead, it appeared that if infection was successfully established in the midgut, replication and dissemination were largely normal. Our results support the hypothesis that replication is an important factor in allowing SINV to overcome the midgut escape barrier, but hint that other factors are also likely involved.When a mosquito ingests an arbovirus during a blood meal, the arbovirus must escape from the midgut of the vector and infect the salivary glands in order to be transmitted to a new host. We used tissue-specific miRNA targeting to examine the requirement for Sindbis virus (SINV) to replicate in midgut epithelium in order to cause disseminated infection in the mosquito Our results indicate that specifically reducing the ability of SINV to replicate in the mosquito midgut reduces its overall ability to establish infection in the mosquito, but if infection is established, replication and dissemination occur normally. These results are consistent with an importance for replication in the midgut epithelium in aiding arboviruses in crossing the midgut barrier.
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http://dx.doi.org/10.1128/JVI.00136-21DOI Listing
April 2021

Global Analysis of Small Non-Coding RNA Populations across Tissues in the Malaria Vector, .

Insects 2020 Jun 30;11(7). Epub 2020 Jun 30.

Department of Biology and Geology, University of South Carolina-Aiken, Aiken, SC 29801, USA.

Malaria is a major global health problem, where the anautogenous female mosquito serves as a major vector. In order to combat this devastating disease, understanding mosquito physiology is paramount. Numerous studies in the vector field demonstrate that small non-coding RNAs (ncRNAs) play essential roles in numerous aspects of mosquito physiology. While our previous miRNA annotation work demonstrated expression dynamics across differing tissues, miRNAs represented less than 20% of all small ncRNAs in our small RNA-Seq libraries. To this end, we systematically classified multiple small ncRNA groups across mosquito tissues. Here we (i) determined a new enriched-midgut miRNA, (ii) updated the piRNA annotation in ovaries with a genomic map of unique-mapping piRNAs, (iii) identified pan-tissue and tissue-enriched mRNA-derived small ncRNAs, and (iv) assessed AGO1- and AGO2- loading of candidate small ncRNAs. Continued research will broaden our view of small ncRNAs and greatly aide in our understanding on how these molecules contribute to mosquito physiology.
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http://dx.doi.org/10.3390/insects11070406DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7411766PMC
June 2020

Small RNA-Seq Analysis Reveals miRNA Expression Dynamics Across Tissues in the Malaria Vector, .

G3 (Bethesda) 2019 05 7;9(5):1507-1517. Epub 2019 May 7.

Division of Biology, Kansas State University, Manhattan, KS 66506 and.

Malaria continues to be a major global health problem, where disease transmission is deeply linked to the repeated blood feeding nature of the anautogenous mosquito. Given the tight link between blood feeding and disease transmission, understanding basic biology behind mosquito physiology is a requirement for developing effective vector-borne disease control strategies. In the mosquito, numerous loss of function studies with notable phenotypes demonstrate microRNAs (miRNAs) play significant roles in mosquito physiology. While the field appreciates the importance of a handful of miRNAs, we still need global mosquito tissue miRNA transcriptome studies. To address this need, our goal was to determine the miRNA transcriptome for multiple tissues of the pre-vitellogenic mosquito. To this end, by using small RNA-Seq analysis, we determined miRNA transcriptomes in tissues critical for mosquito reproduction and immunity including (i) fat body-abdominal wall enriched tissues, (ii) midguts, (iii) ovaries, and (iv) remaining tissues comprised of the head and thorax. We found numerous examples of miRNAs exhibiting pan-tissue high- or low- expression, tissue exclusion, and tissue enrichment. We also updated and consolidated the miRNA catalog and provided a detailed genome architecture map for the malaria vector, This study aims to build a foundation for future research on how miRNAs and potentially other small RNAs regulate mosquito physiology as it relates to vector-borne disease transmission.
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http://dx.doi.org/10.1534/g3.119.400104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6505144PMC
May 2019