Human Brain Gene BC200 Discovered Inside a Virus Genome
Scientists have made a striking genetic discovery, finding that a human brain gene has retained the ability to move and insert itself into the genome of a virus. The research reveals an unexpected biological dual life for a genetic element previously thought to have settled into a fixed role within human cells.
The gene, known as BC200, is a noncoding RNA found exclusively in humans and related primates. First discovered in the late 1980s, it is particularly abundant in human neurons, where evidence suggests it plays a key role in regulating how messenger RNAs are translated into proteins. Although it evolved millions of years ago from a transposable element—commonly referred to as a “jumping gene”—most genes originating this way eventually lose their mobility through a domestication process.
However, new research published in Science by a team of investigators, including researchers at Cornell University, demonstrates that BC200 has bucked this trend. Using specialized software to screen for transposable element-related sequences across viral genomes, scientists detected clear molecular footprints of BC200 inside the genome of the molluscum contagiosum virus (MCV), a benign poxvirus that infects human skin and causes small, raised lesions or papules.
How the Human Gene Jumped Into the Virus
Further genetic analysis indicated that BC200 integrated itself into the viral genome at least twice during modern human history through independent jumping events. Researchers concluded that during infection, a cellular pathway known as LINE-1 converted BC200 RNA back into DNA and inserted distinct copies directly into the viral genome.
Several clues verified the human origin of the viral insertions. BC200 occurs exclusively in humans and primates, while the molluscum contagiosum virus naturally infects only humans. Furthermore, examinations of other poxvirus genomes—including a closely related virus that infects horses—revealed no corresponding elements.
Although BC200 RNA is predominantly expressed in brain tissue, it is also expressed at lower levels in skin cells and germ cells like sperm and eggs. Researchers observed increased BC200 expression in cultured human fibroblasts infected with the virus, providing a plausible window for how the genetic material transferred from host skin cells into the viral pathogen.
Implications for Genetics and Future Research
The findings challenge long-held assumptions about gene domestication and viral interactions. By showing that a gene can perform an active biological function in brain cells while maintaining the capacity to leap into new host genetic environments, the discovery uncovers a unique mechanism of genetic exchange.
While the exact physiological consequences of these viral insertions remain to be fully understood, the presence of BC200 at low levels in germ cells also suggests a theoretical potential for generating inheritable insertions across generations. Scientists continue to investigate the broader implications of how human genetic elements interact with viral pathogens and whether similar mobile genes maintain active double lives.