A joint study conducted by researchers at University of Sheffield and University of Murcia suggests that female pigs are able to determine whether a sperm produces a male or female offspring even before it reaches and fertilizes an egg and their reproductive systems prepare for the birth by changing the fallopian tubes in response.
The researchers conducted their study on a group of female pigs by inseminated them with sperm that was either all X or all Y sperm.
While the natural ratio should be 50:50, on analyzing the pigs' oviduct gene expression, the researchers found that the amount of protein produced by 501 genes varied depending on whether an X sperm or Y sperm was present, concluding that the pigs were able to unconsciously influence the sex of their offspring.
"What this shows is that mothers are able to differentiate between the sperm that makes boys and girls. That on its own is amazing. It's also of great scientific and evolutionary importance. If we understand how they can do that, this can revolutionize the field", lead author of the study Professor Alireza Fazeli said.