Over the years ahead, the term “somatic recombination” may make its way into the lexicon of more lawyers. Why? Because a new, high quality study (published in Nature) shows that brain neurons appear to include mechanisms that intentionally induce somatic changes in brain cells. Some are calling it a “landmark” study. That said, it is an “early days” results that will need confirmatory studies and much more work. That said, it raises interesting questions, including whether a mechanism of that sort could be part of Parkinson’s or other diseases/conditions.
A November 21, 2018 news article in Science provides a summary of some of the findings and possible implications:
“Rather than having one constant blueprint that stays with us throughout life, neurons have the ability to change that blueprint,” Chun proposes. That capability may benefit neurons by enabling them to generate a medley of APP versions that enhance learning, memory, or other brain functions. On the other hand, somatic recombination may promote Alzheimer’s disease in some people by producing harmful versions of the protein or by damaging brain cells in other ways, the scientists conclude.
Where do all these gene variants come from? Chun and his team think gene reshuffling depends on an enzyme called reverse transcriptase that makes DNA copies of RNA molecules. A new variant could arise when a neuron produces an RNA copy of the APP gene—this step is part of the cell’s normal procedure to produce proteins. However, reverse transcriptase may then recopy the RNA molecule to make a DNA duplicate of the APP gene that slips back into the genome. But because reverse transcriptase is “a sloppy copier,” Chun says, this new version may not match the original gene, and it may code for a different variant of APP. Drugs that block reverse transcriptase are part of the standard treatment cocktail for HIV infection, and they might also work against Alzheimer’s disease, Chun suggests.”