Mosquitoes can’t spot sterile mate
19 Sep 2011 by Evoluted New Media
Female mosquitoes have only got one chance – they only ever mate once in their lifetime – but it turns out they can’t tell if they’ve picked a fertile or spermless male.
Female mosquitoes have only got one chance – they only ever mate once in their lifetime – but it turns out they can’t tell if they’ve picked a fertile or spermless male. Researchers from Imperial College London found that female mosquitoes who attempted to breed with a sterile male behaved the same as they would if they had mated with a fertile male. Their finding could be one way to prevent the spread of malaria.
Researchers produced 100 spermless males of the species Anopheles gambiae – the mosquito primarily responsible for the transmission of malaria in Africa – by injecting ordinary mosquito eggs with a protein that disrupted the development of their testes. This prevented them from producing sperm in adulthood, but did not interfere with any other sexual function or behaviours in the male – or female.
“In the fight against malaria, many hope that the ability to genetically control the mosquito vector will one day be a key part of our armoury,” said Dr Flaminia Catteruccia. “In order for these currently theoretical control strategies to work we need to make sure that the insects continue to mate as normal, unaware that we have interfered with their sexual mechanisms.”
After mating for the one and only time in her life, the female mosquito undergoes certain physiological changes, then eats a blood meal and lays a batch of eggs. Researchers observed that the female’s behaviour was the same regardless of whether the mate was fertile or sterile – females made no attempt to find another mate, missing out on the chance to reproduce and pass on their genes if the mate was sterile.
Researchers isolated mating couples in the laboratory and closely observed their behaviour and physiology during key stages of reproductions, looking for certain characteristics in non-fertile mating couples.
This study – published in Proceedings of the National Academy of Sciences – strongly suggests that female mosquitoes cannot tell the difference between a fertile and spermless mate, said Catteruccua.
