Although the common knowledge for decades established DNA as the genetic code of life, recent research in the field of epigenetics demonstrates that our DNA sequence does not strictly determine our inherited traits (1).
Epigenetics (the study of how external and environmental factors affect the genome) investigates the methylation of DNA, which causes genes to be activated or inactivated, and can be inherited transgenerationally, similarly to how the actual DNA sequence is inherited. Genes can also be turned on or off by the methylation of histones, which are spool-like proteins around which the DNA coils. However, whether the methylation of histones is inherited across generations is still highly questionable (1).
The above diagram demonstrates how histone modifications influence the expression of genes
Source: Wikimedia Commons
Researchers at the University of Edinburgh’s School of Biological Sciences successfully showed that these histone modifications are, in fact, heritable, using a study on yeast cells. The team was able to induce modifications to the yeast’s histone methylation, which induced drug tolerance, and observe these changes perpetuate across many generational lines, proving the heritable nature of histone methylation. On the findings, study leader Professor Robin Allshire stated, “We’ve shown without doubt that changes in the histone spools that make up chromosomes can be copied and passed through generations” (1).
These findings pave the way for future investigations into what influences these non-genetic factors and how the altered forms of the epigenome affect health. Since environmental factors can affect epigenetic traits, these results raise questions pertaining to how lifestyle choices, such as diet, exercise, and stress, may influence the inherited epigenetic signature of future generation (or one’s children) (1).
References
1) University of Edinburgh. (2015, April 2). DNA can’t explain all inherited biological traits, research shows. ScienceDaily. Retrieved April 4, 2015 from www.sciencedaily.com/releases/2015/04/150402161751.htm