The human genome, which is like a complex book of life's instructions written in our genes, holds some interesting surprises. One of these surprises comes from bits of DNA that can move around inside our genetic code – they're called "transposable elements" (TEs).
These TEs don't just sit still; they can jump around in the genome. While this movement can cause changes and mix-ups in our genetic material, TEs also play a crucial role in organizing and expressing our genes. They contribute to things like regulatory elements and the creation of hybrid RNA molecules, formed when different genetic segments join together.
Scientists have recognized that TEs make up about half of our DNA. But as they move and age, they undergo changes that make them hard to recognize. Over time, they "degenerate," becoming less identifiable, making it a challenge for scientists to spot and track them in our genetic code.
In a recent study led by researchers in Didier Trono's group at EPFL, a cool trick was used to better find these tricky TEs in the human genome. They took a journey through time, using reconstructed ancestral genomes from various species as a reference. This genomic "time machine" helped them identify TEs that had become hard to spot in the human genome due to wear and tear over millions of years.
By comparing our genome with these ancient versions, the researchers found TEs that might have been overlooked in earlier studies focusing only on the human genome. This method revealed a larger number of TEs than we knew before, increasing the portion of our DNA contributed by TEs. What's even more fascinating is that these newly discovered TEs still played the same important roles as their more recent counterparts.
The possibilities opened up by this discovery are huge. Understanding TEs and how they are controlled could give us valuable insights into various human diseases influenced by genetic factors. Diseases like cancer, autoimmune conditions, metabolic disorders, and even how our bodies respond to stress and aging could all benefit from a better grasp of these jumping genetic elements.