A team of scientists from the University of California, Riverside, has unlocked a genetic secret: a long-hypothesized male determining gene in the mosquito species that carries malaria. This discovery will lay the groundwork for the development of strategies and treatments that could help fight malaria. The published paper is named “”Radical remodeling of the Y chromosome in a recent radiation of malaria mosquitoes” and was co-authored by 28 scientists from four countries and four universities in the US.
Y chromosomes control essential male functions such as fertility and sex determination in many species, however, knowledge of the Y chromosome genetic sequence is quite limited. That’s why this new discovery provides a long awaited platform for studying male mosquito biology, which offers a potential to create new vector control strategies to fight diseases such as malaria.
One vector control method currently under development involves genetic modification of the mosquito to bias the population sex ratio to males, which do not bite, with the intention of reducing or entirely eliminating the population. Modeling has shown that the most effective way for genetic modification is engineering Y chromosome. A molecular-level understanding of the Y chromosome of the malaria mosquito is crucial to inform and optimize such a strategy.
The researchers used multiple genome sequencing techniques, including single-molecule sequencing and Illumina-based sex-specific transcriptional profiling, as well as whole-genome sequencing, to distinguish an extensive dataset of Y chromosome sequences and explore their formation and evolution in Anopheles gambiae complex. Anopheles gambiae complex is a group of at least seven morphologically indistinguishable species of mosquitoes in the genus Anopheles which carry some of the most important vectors of human malaria. They discovered only one gene, known as YG2, which is exclusive to the Y chromosome across the species complex, and, therefore, is a possible male-determining gene.