Tuesday, August 24
Signals sent by Sonic Hedgehog Help Ensure a Healthy Baby
Interfering with developmental signals sent by the sonic hedgehog protein to a fetus can cause debilitating birth-defects. Although interference early in development creates cyclopic embryos, progressively later interference mimics the entire range of symptoms seen in children with the birth-defect holoprosencephaly, or HPE. Intriguingly, interference after sonic hedgehog has already established itself in the divided brain affects only the embryo's face, and holding off just a bit longer results in no detectable malformation of either brain or face.
Scientists believe that HPE may arise from a combination of a faulty sonic hedgehog gene, present from conception, and varying times of exposure to environmental factors that further compromise the protein's signaling. In this scenario, early exposure leads to more severe defects and sometimes death, while later exposure can leave a child with only minor facial abnormalities.
Play Sonic the Hedgehog | About Sonic Hedgehog (the protein)