Exploring Loops in the Human Genome: Dr. Erez Lieberman Aiden Explains His Research

Dr. Aiden works on analyzing the bending of our human genome, a 3-D complex arrangement that, in part, regulates our cells. This conversation explores

• how each chromatid forms unique loops and bends while patterns emerge across similar cell types,
• the mechanism that forms these loops—a protein complex that works almost like a lariat knot of a lasso, and
• why a better understanding of this molecular genetics architecture is important for medical treatments.

Dr. Erez Lieberman Aiden is an assistant professor of molecular and human genetics at Baylor College of Medicine. Over the course of the podcast, he describes how this architectural feat of our cells' genome is formed and the accompanying implications of the nature of this formation. As he explains the complexity of molecular genetics, he begins with a description of how this two-meter-long DNA strand fits inside each of our nuclei. Further, because the sequencing of the human genome is such a recent scientific accomplishment, our understanding of these bending twists and loops is growing almost daily.

He explains that this intricate packing of the human genome is not just a storage mechanism. Rather, as is the case with proteins, shape is essential to function—these physical loops form and bring enhancer elements in relation to a significant gene, for example. He adds that typically loops bring promoters of genes in contact with other elements in the genome to exchange information. All this gives rise to genetic regulation, which includes turning genes on and off.

Dr. Aiden also explains the practicalities of how these molecular genetics studies are accomplished, such as what microscopy enables them to see. Finally, he discusses some of the implications of this research: scientists ask why we have the same genome in the brain and the heart yet the cells do different jobs. It's clear the gene changes how it folds in different organ systems and that fold changes how each cell functions.

For more, see his lab page at https://www.aidenlab.org/ , which includes links to all the data from their research, and a recent article he published in Scientific American that explores aspects of these themes: https://www.scientificamerican.com/article/human-genome-3-d/.