Mosquito sperm have 'sense of smell'

Researchers have claimed to have detected a suite of specialized chemical sensors called odorant receptors (ORs) in mosquito sperm.

They say that these are the same as the sensors that play a central role in the mosquito's olfactory system, which is found on the insect's antennae.

The researchers found that the odorant receptors in the sperm are expressed along their tails where they drive the rapid increase in the movement (beating) of the sperm tails.

Research Assistant Professor Jason Pitts said that the sperm may need a chemical signal to become ready for fertilization, asserting that there are reports that within one day after insemination, the sperm begin swimming around in the spermathecae.

He said that there must be one or more signals that activate this movement and our findings suggest that odorant receptors may be the sensor that receives these signals.

The researchers have also tested three additional insect species - the Asian Tiger mosquito Aedes albopictus, the fruit fly Drosophila melanogaster, and the jewel wasp Nasonia vitripennis - and found that their sperm also contain odorant receptors.

According to the researchers, this suggests that ORs have a general function in reproduction across most, if not all, species of insects.

The study has been published online in the Proceedings of the National Academy of Sciences.