In recent decades the global incidence of dengue has risen significantly. Approximately half the world population is now at risk. An approximate 100-400 million infections occur per year. So tackling dengue has become extremely difficult for the government. Dengue is a mosquito-borne viral disease which is caused by the bite of female mosquitoes mainly of the species Aedes Aegypti that transmit the dengue virus (DENV) while feeding on the blood of the infected person. This female mosquito carries the four variants of the dengue virus- DEN-1, DEN-2, DEN-3, and DEN-4 which belongs to genus Flavivirus, family Flaviviridae. These viruses cause a wide range of diseases that ranges from subclinical disease (people may not know they are infected) to severe flu-like symptoms.
There is no specific treatment for dengue/severe dengue. Dengue prevention and control depends entirely on the vector control measures of the countries or localities. But recently, a study done by some researchers proved that the increasing cases of dengue fever can be tackled by turning female mosquitoes into males. Research at Virginia Tech has shown how altering one gene can turn female Aedes aegypti mosquitoes into fertile male mosquitoes. The location of this gene and its subsequent alteration may be all-important for the control of the mosquitoes. The gene for male mosquito flight is the one required.
An important distinguishing feature between male and female mosquitoes is that male mosquitoes do not bite and thus can not spread pathogens to humans. The evolutionary explanation that the female mosquitoes Aedes Aegypti require blood is to produce eggs. So tackling dengue can be done by reducing the number of female mosquitoes, The mechanism for controlling female numbers lies on the male-determining locus (M locus), which consists of 30 genes. The researchers identified a second gene, called myo-sex, necessary for male flight. Learning this showed something more about the M locus. In the mosquito, the locus determines male sex. Only the male offspring inherit the gene, in a way that resembles the human Y chromosome. The researchers showed that this one gene was sufficient to breed mosquitoes with male-specific sexually dimorphic features and thus male-like gene expression by manipulating these. The importance of this is mosquito generation that won’t bite and thus won’t transmit disease.
The research has been published in Proceedings of the National Academy of Sciences, and the paper is titled “Nix alone is sufficient to convert female Aedes aegypti into fertile males and myo-sex is needed for male flight.”