To make eggs, a female mosquito must eat a blood meal and mate. But how copulation triggers the development of proto-eggs, known as oocytes, is not well understood. Now, experiments on the malaria-carrying mosquito Anopheles gambiae are yielding clues. A hormone called 20E – abundant in the jelly-like mating plug that males deposit in females after sex – stimulates production of a protein called MISO, known to be important for oocyte production. The 20E binds to the MISO, creating an amalgam that activates genes associated with egg development and ramps up the production of molecules called lipids [fats] that nourish proto-eggs. Here, two oocytes have accumulated lots of lipids (stained red), a process that relies on 20E delivered by males, which in effect tells females to allocate extra resources to egg development. If scientists can block this molecular pathway, they could find new ways to limit mosquito numbers and control malaria.
Written by Daniel Cossins
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