Weird intersex mosquitoes may be key to stopping Dengue, Chikungunya
Researchers at Virginia Tech, US have uncovered a method to control mosquito populations, which could offer an alternative to insecticides. Their study focused on the genetic incompatibility of species, by crossbreeding Aedes aegypti, a primary vector for diseases like Dengue, with its sibling species, Aedes mascarensis from the Indian Ocean. The scientists found that when the offspring of Aedes aegypti and Aedes mascarensis, were crossed back with one parent, around 10% of the progeny were intersex, and unable to reproduce.
Key to population control
These intersex mosquitoes, despite being genetically male, express both male and female genes, resulting in mixed physical traits. The researchers aim to use this understanding to develop strategies for making all-male mosquito populations, which could help control mosquito numbers by eliminating females. According to Igor Sharakhov, one of the researchers on the project, "This study can help identify new sex determination pathway genes that can be used in mosquito control strategies."
Intersex mosquitoes could improve future vector control methods
The research could also aid in identifying genes that influence female mosquito behavior, potentially improving future vector control methods. Jiangtao Liang, a postdoctoral associate in entomology, stated, "Since the intersex is genetically male but expresses female transcripts, it provides a system to identify genes affecting female behavior." The researchers examined morphological and anatomical aspects of intersex mosquitoes- genes involved in the sex determination pathway; and overall gene expression related to sexual differentiation.
Morphological abnormalities in intersex mosquitoes explored
Sharakhov explained that the morphological abnormalities in intersex mosquitoes begin during the pupal stage of development. The researchers discovered that these mosquitoes show both male as well as female variants of sex-determination genes. While female-biased genes are expressed as expected, the male-biased genes depict reduced expression in some male reproductive structures. However, genes associated with the testes remain at normal levels.
