Mosquito-borne diseases have a devastating impact on public health around the world. The yellow fever mosquito, Aedes aegypti, is the primary global vector for dengue virus transmission. Because of its epidemiological importance, Ae. aegypti is one of the most intensively studied mosquitoes in various aspects of genetics, vector-pathogen interactions, and transgenic research. Recent publication of the complete genome sequence for Ae. aegypti has stimulated research in vector biology and insect genomics. However, a lack of high-quality genome assembly placement to chromosome position remains a significant impediment to further research progress. The absence of readable polytene chromosomes makes physical mapping for this mosquito extremely challenging. The current physical map has relatively low resolution and includes ~180 physical markers. Only a third of the Ae. aegypti supercontig assemblies has been assigned to chromosomes, but without linear orders and orientation. We have recently discovered that prometaphase chromosomes from imaginal discs of 4th instar larvae can be an excellent source for the physical mapping of the Ae. aegypti genome for the following reasons: large size of the chromosomes, high numbers of mitotic phase chromosomes on each slide preparation, and the reproducible banding pattern of the individual chromosomes.
The specific aims for this project are to 1. Develop a cytogenetic map for Ae. aegypti based on banded prometaphase chromosomes from imaginal discs of 4th instar larvae. 2. Place about 70% of the genome supercontig assemblies to their precise chromosomal locations. This developmental project will modernize cytogenic research for Ae. aegypti and greatly improve the current fragmented genome assembly. We believe that the availability of a high-resolution physical map will accelerate progress in a number of ongoing projects with Ae. aegypti, as well as enhance vector biology and insect genomics overall, and will further stimulate research in mosquito systematics, population genetics, and insect comparative genomics.

Public Health Relevance

Aedes aegypti is the primary global vector for dengue virus. Dengue is an emerging health threat throughout subtropical and tropical regions around the world. No vaccines or drug treatments are available;thus, disease prevention is largely based on efforts to control or avoid contact with infected mosquitoes. The proposed research will develop new genome tools that will greatly enhance the utility of the existing draft genome sequence assembly for Ae. aegypti and thereby facilitate application of advanced genome technologies for investigating and developing novel genetic control strategies for dengue transmission.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI088035-02
Application #
8137887
Study Section
Special Emphasis Panel (ZRG1-IDM-M (02))
Program Officer
Costero, Adriana
Project Start
2010-09-03
Project End
2013-08-31
Budget Start
2011-09-01
Budget End
2013-08-31
Support Year
2
Fiscal Year
2011
Total Cost
$227,450
Indirect Cost
Name
Virginia Polytechnic Institute and State University
Department
Zoology
Type
Schools of Earth Sciences/Natur
DUNS #
003137015
City
Blacksburg
State
VA
Country
United States
Zip Code
24061
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Timoshevskiy, Vladimir A; Kinney, Nicholas A; deBruyn, Becky S et al. (2014) Genomic composition and evolution of Aedes aegypti chromosomes revealed by the analysis of physically mapped supercontigs. BMC Biol 12:27
Hall, Andrew Brantley; Timoshevskiy, Vladimir A; Sharakhova, Maria V et al. (2014) Insights into the preservation of the homomorphic sex-determining chromosome of Aedes aegypti from the discovery of a male-biased gene tightly linked to the M-locus. Genome Biol Evol 6:179-91
Timoshevskiy, Vladimir A; Severson, David W; Debruyn, Becky S et al. (2013) An integrated linkage, chromosome, and genome map for the yellow fever mosquito Aedes aegypti. PLoS Negl Trop Dis 7:e2052
Timoshevskiy, Vladimir A; Sharma, Atashi; Sharakhov, Igor V et al. (2012) Fluorescent in situ hybridization on mitotic chromosomes of mosquitoes. J Vis Exp :e4215
Severson, David W; Behura, Susanta K (2012) Mosquito genomics: progress and challenges. Annu Rev Entomol 57:143-66
Sharakhova, Maria V; Timoshevskiy, Vladimir A; Yang, Fan et al. (2011) Imaginal discs--a new source of chromosomes for genome mapping of the yellow fever mosquito Aedes aegypti. PLoS Negl Trop Dis 5:e1335