Researchers at Cornell University have identified a human gene with an unusual characteristic: it maintains mobility typically associated with transposable elements while simultaneously serving an important biological function in brain cells. The discovery, detailed in a study published September 24 in Science, centers on a genetic element called BC200, which is primarily expressed in neurons but has evolutionary origins tracing back millions of years to a transposon, commonly referred to as a jumping gene.
Transposable elements are non-coding genetic segments capable of relocating within a genome and inserting themselves at new locations. While such elements can sometimes cause harm by disrupting normal gene function, they have also contributed to genomic diversity and evolution over long timescales. Approximately half of the human genome consists of DNA derived from transposons, though most are no longer active. Only a small fraction retain the ability to move and duplicate themselves within genomes. BC200 represents a notable exception, having retained its mobility despite being repurposed for cellular functions. According to Cedric Feschotte, a senior study author, genes originating from transposable elements are typically no longer transposable, making BC200’s dual nature scientifically significant.
The discovery emerged when researchers found BC200 within a poxvirus, marking a rare documented case of a human transposable element jumping into a virus. While scientists have observed transposons moving into viruses in other species, BC200 is found only in humans and closely related primates. Researchers first identified BC200 in the late 1980s as a highly abundant non-coding RNA in human neurons. Current evidence suggests the gene may help regulate how messenger RNAs are translated into proteins within neurons. The element also appears at low levels in reproductive cells, indicating potential for inherited genomic changes in future generations.
Researchers propose that BC200 may have transferred to the molluscum contagiosum virus during skin cell infection. The gene has gained additional scientific interest due to abnormal expression patterns in certain tumors and elevated levels detected in brains of individuals with Alzheimer’s disease. These observations raise questions about whether BC200’s mobility could contribute to disease development. Future research aims to clarify whether the molluscum contagiosum virus exploits BC200 to modify host cells and whether BC200 activity in cancer cells generates mutations.
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