Cellular packaging of DNA, Henning Dalhoff, UIG
Cellular packaging of DNA, Henning Dalhoff, UIG


There is one basic reason for the existence of humans with big brains, certain orchids that mimic the reproductive organs of insects, bacteria resistant to antibiotics and many forms of cancer. All are examples of how genes and their environment interact. Humans who leveraged their intelligence were more likely to survive. Orchids that attract insects are better pollinated. But many changes in DNA and how it is expressed (which genes are activated) damage the organism and cause diseases like cancer.

More to genetics than just DNA

One of the most exciting areas of current research is epigenetics – the study of inherited traits that are not explained by changes in DNA. In this case “inherited” can mean inherited from one cell to another, not just from parent to child. The causes of epigenetic changes are often environmental – diet, aging, drugs, and chemicals – and can result in cancer, diabetes, and mental and autoimmune disorders, diseases which kill over 45% of Westerners and afflict many others.  

Whether or not these environment-caused changes in the genome are outwardly visible, they all occur through molecular mechanisms at the microscopic level. Science has made big strides in understanding biochemical reactions that are responsible for gene expression, but discovering how these complex reactions are coordinated within the cell is still a question mark.

Protein complexes manipulate gene expression

DNA and RNA are shaped, protected, replicated, expressed and degraded by complexes of proteins. Chromatin bundles up DNA, and how it unfurls the DNA controls how the genes are expressed. The exosome, another protein complex, acts as “quality control” for RNA as well as degrading/recycling it after use. Both chromatin and the exosome play fundamental roles in preserving the integrity of the genome and regulating which genes are expressed, responding to both internal genetic programs and external environmental cues.

“Environmental factors” can cause previously inactive genes to be expressed, and this change in how DNA acts, rather than what composes it, is the primary issue in epigenetics.

“Basic” science fundamental to future progress    





Neus Visa, Professor in Molecular Biosciences, Wenner-Grens Institute, researches how gene expression is coordinated and regulated, focusing on the exosome, a protein complex which degrades RNA and also affects gene expression.

Mattias Mannervik, Professor in Molecular Biosciences, Wenner-Gren Institute, researches how gene expression leads to the creation of different types of cells (skin, muscle, nerve, etc.) from the same DNA.


Both researchers describe “basic” research for understanding the epigenetic factors that lead to disease. The path to biomedical breakthroughs might be unpredictable, but it certainly wouldn’t happen without the foundation being laid.

These selected examples of research coming from the Gene-Environment Interaction profile area are just two of dozens. Researchers at Stockholm University examine every conceivable level of the issue - from molecules and cells to organisms and entire populations, providing the bedrock knowledge upon which technologies and applications will be built.