Genomic Imprinting and the Brain

What is genomic imprinting? Which organisms demonstrate genomic imprinting? Professor of Molecular and Cellular Biology at Harvard University, Catherine Dulac, addresses the exciting connections between genomic imprinting and brain development.

Genomic imprinting is a very fascinating phenomenon. It originates from the fact that all our cells possess two copies of each gene. One copy is inherited from mom, and the other is inherited from dad. So at fertiliяation, the egg and the sperm fuse their genomic information, and so we have half of our genome that is of maternal origin and half of paternal origin.

Internal metric of space is influenced by geometry of environment New Nature paper reveals that brain perceives distance differently depending on surroundings

This was only a hypothesis, and as it turns out a couple of years later the first imprinted genes were discovered, and the first paternally expressed gene is a growth factor, called IGF2. The first maternally expressed gene discovered is an IGF2 receptor, which is a truncated receptor which impairs the function of IGF2.

So why is this important? What we think is happening is that by silencing one of the two parental copies a neuron or brain area is trying to regulate the dosage of certain genes, and that the regulation of gene dosage is essential for proper brain function. In fact, there are quite a number of neurological diseases in which improper gene dosage leads to catastrophic impairment of brain function.