Sex Can Shake Up Female Genes In More Ways Than One

Sex may have more of an effect on our bodies than we think it does.

Sure we know some of the feelings and sensations involved in sex, but did we know about changes in eating, sleeping patterns and libido?

Eh, no, says us.

Research has shown that sex can trigger “remarkable” responses in women, including altered fertility, immunity, libido, eating and sleep patterns. This happens by the activation of diverse sets of genes, the study says.

The researchers investigated the sex experiment with fruit flies, but said their findings could be related to many animals, including humans, where sperm is released inside the female’s body during sex.

Scientists from the University of East Anglia (UEA) studied how female fruit flies responded to mating. Rather them than us!

They discovered that a single protein in semen generates a wide range of responses in many genes in females. These responses and changes become evident at different times and in different parts of the female’s body following mating.

The lead researcher at the university, Professor Tracey Chapman (no relation to thee Tracey Chapman), said they see the semen protein as the “master regulator”, which ultimately means that males effectively have a direct and global influence on the behaviour and reproductive system of the female.  

“An additional and intriguing twist is that the effects of semen proteins can favour the interests of males whilst generating costs in females, resulting in sexual conflict,” Professor Chapman said.

For example, there can be a tug-of-war, where males employ semen proteins to ensure that females make a large investment in the current brood - even if that doesn’t suit the longer term interests of females."

Professor Chapman said the semen protein they studied is called the “sex peptide”. They already knew that semen created effects in females such as feeding, immunity, sleep patterns, water balance and sexual receptivity.

Now they know that this one seminal fluid protein can change an array of many genes in the females, both across time and different parts of the body.

The findings were published in the journal Proceedings of the Royal Society B.