
22/02/2025
Babies in the womb can signal to their mothers for extra food using genes from their dads.
This fascinating mechanism, uncovered by scientists at Cambridge, involves a paternal gene that influences hormonal signals from the placenta. Essentially, the fetus uses this gene to manipulate the mother's body into releasing more nutrients, creating a "nutritional tug of war" where the mother must balance the needs of the growing fetus with her own health and future reproductive potential.
The placenta plays a key role in this process, acting as a communication hub between the fetus and the mother. By releasing specific hormones, the placenta signals the mother's body to prioritize the baby's growth, ensuring it receives sufficient glucose and fats.
This intricate system is orchestrated by imprinted genes, which can be switched on or off depending on whether they are inherited from the mother or the father. Paternal genes tend to promote fetal growth, while maternal genes tend to limit it, reflecting an evolutionary balance between the needs of the offspring and the mother's survival.
One such paternal gene, Igf2, provides instructions for making a protein similar to insulin that promotes fetal growth and development. When this gene is deleted in the placenta's signaling cells, the mother doesn't release enough nutrients into her circulation, resulting in growth restriction in the fetus.
This reveals the crucial role of Igf2 in regulating the mother's metabolism and ensuring adequate nutrient supply to the developing baby.
Learn more: https://www.cam.ac.uk/research/news/unborn-babies-use-greedy-gene-from-dads-to-remote-control-mums-into-feeding-them-extra-food