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.
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.
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