A father’s DNA makes a baby greedy in the womb — while a mother’s genes try to stunt growth, a study says.
The paternal side forces a mother to deliver sugar and fat to the fetus while focusing on making sure the fetus is not too big for birth.
At the heart of this “tug of war” is insulin-like growth factor 2, or IGF-2 – a protein that reduces the amount of nutrients the body absorbs from food.
A father’s DNA stimulates a fetus to produce them, preventing the mother from using up nutrients, leaving more for the infant.
This was found by experts from the University of Cambridge in tests on mice.
They turned off the male IGF-2 gene and found that the mother’s body was not giving the fetus enough sugar.
dr Miguel Constancia said, “Genes controlled by the father are ‘greedy’ and ‘selfish’ and manipulate the mother’s resources in order for fetuses to grow tall and fit.”
Co-author Prof Amanda Sferruzzi-Perri said maternal genes that limit fetal growth should ensure their survival.
She said, “That’s because she’s not having a baby that’s getting all the nutrients and is too big and difficult to deliver.”