Scientists at the Van Andel Institute, in collaboration with other researchers, have made a significant discovery regarding the mechanism of genetic imprinting. Genetic imprinting is a vital biological process in which one parent’s gene is turned off while the other parent’s copy remains active. Understanding this process is crucial, as errors in imprinting have been linked to various diseases, including Silver-Russell syndrome, certain cancers, and diabetes.
In a recent study published in the journal Science Advances, the scientists unveiled a key part of the mechanism that annotates genetic information before it is passed from fathers to their offspring. Genetic information is encoded in DNA, which forms 23 pairs of chromosomes, half of which come from the father and the other half from the mother. During fertilization, the sperm and the egg each contribute their genetic material, resulting in a zygote with a full set of chromosomes.
However, not all DNA instructions are needed at the same time or in the same places. This is where epigenetics comes into play. Epigenetic mechanisms add chemical tags called methyl groups to DNA, which determine which genes should be active or silent without altering the DNA sequence itself.
During imprinting, methyl groups are added to specific genes during the formation of sperm or eggs. This process is crucial in determining which copy of a gene from the parents will be expressed in their offspring. The scientists focused on an imprinting control region in the DNA that regulates the Igf2 gene, which plays essential roles in fetal growth and is only active in the chromosome inherited from the father. Insufficient methylation in this region can lead to Silver-Russell syndrome, characterized by reduced growth and an increased risk of metabolic disease.
Through genetic models and in-depth genetic sequencing, the researchers discovered that the methylation of the Igf2 control region in paternally inherited DNA is governed by an RNA-based process in the male germline. They also found similar results in other paternally marked imprinted domains in male germ cells, suggesting a broader applicable process.
This groundbreaking discovery sheds new light on the mechanisms involved in genomic imprinting and provides valuable insights into why imprints differ between fathers and mothers. The findings pave the way for further research and a deeper understanding of the factors that regulate this crucial process.
Overall, this study represents a significant contribution to the field of genetics and highlights the importance of proper imprinting for lifelong health. By unraveling the mechanisms behind genetic imprinting, scientists can potentially develop targeted interventions to prevent or treat diseases associated with imprinting errors.
