Natures wonders:male fruit flies semen changes female brain (Introduction)

by David Turell , Wednesday, November 20, 2019, 20:25 (1828 days ago) @ David Turell

It improves their memory according to this study:

https://www.newscientist.com/article/2224230-semen-seems-to-help-female-fruit-flies-rem...

"Female fruit flies get a boost in their long-term memory after mating thanks to a molecule found in male fly semen. This molecule – called the sex peptide – binds to the sperm of male flies and is passed on to females, where it travels from the reproductive tract to the brain.
It was already known that this molecule, which is unique to fruit flies, alters behaviour.

"After mating, it changes what females prefer to eat and makes them reject future mating partners, for example. It does this by acting on nerve cells, or neurons, located throughout the body.

"Thomas Preat and his colleagues at PSL University, France, found that this molecule also enhances long-term memory by targeting the neurons in the brain responsible for it. “This was very peculiar,” says Preat. “Normally the sex peptide acts on neurons which are connected to the ovaries.”

"To test fruit fly memory, the team conditioned females to pair certain smells with electric shocks. Although flies that had mated could remember to avoid smells associated with shocks, flies that hadn’t mated forgot after four days, showing they couldn’t retain this training in the long term.

"The researchers found that females who mated with males modified to lack the sex peptide didn’t have better long-term memories, but flies that hadn’t mated that were injected with the peptide saw a memory boost, suggesting the molecule was responsible.

"In nature, flies that are yet to mate might lack such a memory in order to make them braver and more likely to search out mating partners. In contrast, long-term memory would benefit flies that have mated so they remember safe spots to lay eggs.

"Stuart Wigby at the University of Oxford says he is surprised that the sex peptide can migrate all the way to the brain and affect learning. “It’s kind of amazing,” he says."

Comment: The bolded paragraph above makes good sense and suggests God might have arranged for this to assure fruit fly survival.