Jumping genes help stabilize DNA fold patterns, The leap of pieces of genetic DNA that can move from one place in the genome to another is known to increase genetic diversity in the course of evolution.
The latest study also talks about transposable elements that play a more surprisingly different role: stabilization of 3D models for folding DNA molecules in the cell nucleus.
DNA molecules in the nucleus of every human cell are more than two meters. To fit in such a small space, it must be folded into the right loop which also controls how genes are turned on or off. It seems counterintuitive that pieces of DNA that happen to move in the genome can ensure the stability of these fold patterns. Jumping genes help stabilize DNA fold patterns.
In fact, this discovery contradicts the long-held assumption that the exact order of the letters in the DNA sequence always determines the wider structure of DNA molecules.
In places where the larger 3D genome folds are the same in mice and humans, it can be predicted that the sequence of letters from DNA that anchor this shape will be maintained there.
But that’s not what we found, at least not in the part of the genome that used to be called “junk DNA”.
When investigating DNA folds in mice and human blood cells, the researchers found that in many regions that had DNA fold patterns during evolution, the genetic sequence of DNA letters recognizing these folds was incorrect. . It shifts easily. However, this sequence of changes, genetic changes, does not cause problems.
Because the structure remains largely the same, the function of the presumption is also fulfilled so that there are no important changes.
The order can be different, but the function remains the same. And we see that this has happened many times in the last 80 million years when the same ancestors of rats and humans were different for the first time.
The fact that new portable elements can be inserted and play the same role as existing anchors leads to the shrinking portion of the regulation of the genomic portion of DNA molecules that determines how and when genes are turned on or off.
According to the researchers, this advantage makes the genome more stable.
By providing novelty and stability, the jumping gene can help the mammalian genome achieve vital balance. This allows animals to adapt flexibly to climate change and at the same time maintain vital biological functions and protect them from DNA damage. caused by life and reproduction of the earth in a deep time, measured in ten to one hundred million years.
However, researchers have carefully distinguished between parts of the genome that make genes responsible for protein production and other parts of the genome. Genes that encode proteins maintain their genetic sequence and structure, and this study does not contradict this.
However, new research shows that genes jump in the non-protein coding region of the genome following different rules to protect them from protein-coding genes.
“Our study changes the way we interpret genetic changes in the region of non-coding DNA,” the researchers said. For example, large genome studies by many people have found many variations in non-coding areas that seem to have no effect on gene regulation, which is confusing.
However, this makes more sense given our new understanding of transposable elements, because the local order can change, but its function remains unchanged. We may need to review this type of research in view of new discoveries about wearable goods.
This study reveals another complex layer in the genome sequence that was previously unknown.