The Aedes aegypti mosquito carries dengue, chikungunya and yellow fever viruses, pathogens that affect millions of people each year. Studying the genetic makeup of this mosquito can help researchers characterize its evolutionary history, determine its patterns of geographic distribution and also study how it transmits disease. Unfortunately, genetic studies of Ae. aegypti have been challenging given the complexities of its genome. To solve this, NIAID-supported researchers developed a single-nucleotide polymorphism (SNP) chip. This tool detects small variations in DNA called SNPs, which can distinguish between populations of mosquitoes around the world. This chip can identify 50,000 SNP locations, and is therefore a powerful tool for studying variations throughout the genome of the A. aegypti mosquito.
Importantly, the researchers shared the data generated through this study in a public database and they encourage other researchers to do the same. As this chip continues to be used for various research studies, the investigators expect that the number of SNPs will grow and the chip may subsequently be improved. By continually adding data to the public domain, this shared resource will assist investigators with new research studies, from examining the geographic spread of mosquito populations to better understanding the genetic bases of infectious disease transmission.
Reference: Evans BR et al. A Multipurpose, High-Throughput Single-Nucleotide Polymorphism Chip for the Dengue and Yellow Fever Mosquito, Aedes aegypti. G3 (Bethesda). 2015 Feb 26;5(5):711-8. doi: 10.1534/g3.114.016196.
NIAID-supported researchers at Virginia Tech Fralin Life Science Institute have identified a gene called Nix, that determines whether Aedes aegypti mosquitoes develop into males or females. This process is known as sex determination. Only female mosquitoes bite humans because they need blood for developing eggs. When female A. aegypti mosquitoes bite, they can also transmit infectious disease agents, such as dengue, yellow fever and chikungunya viruses. The identification of the Nix gene is significant in that it could lead to novel vector control strategies.
Researchers injected the Nix gene into mosquito embryos and found that more than two thirds of the female mosquitoes developed male genitalia. When they removed the Nix gene, male mosquitoes developed female genitalia. While more research into the area is needed, the findings could lead to new methods of reducing A. aegypti female populations in areas where disease transmission is high, significantly improving public health.
Reference: Hall AB et al. A male-determining factor in the mosquito Aedes aegypti. Science, 2015 Jun 12;348(6240):1268-70. doi: 10.1126/science.aaa2850. Epub 2015 May 21.
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Last Updated July 07, 2015