Scientists have discovered a human gene called BC200 embedded in a poxvirus, revealing that a vital brain-function gene can also act as a mobile jumping gene. Published on September 24, the finding blurs the lines between human genetics and virology by documenting a rare natural viral transfer.
Origins and Dual Role of the BC200 Gene
The genetic element known as BC200 originates from an ancient transposon—often dismissed as junk DNA—that was co-opted in a common primate ancestor roughly 40 million years ago. Today, it is found exclusively in humans and related primates. Researchers discovered the gene in the late 1980s as an abundant non-coding RNA in human neurons, where evidence suggests it regulates the translation of neuronal messenger RNAs into proteins.
What sets BC200 apart from standard cellular genes is its stubborn refusal to give up its mobility. While most transposable elements that get repurposed for bodily functions lose their ability to move, BC200 retained its capacity to replicate and jump across genomes.
Cedric Feschotte, Barbara McClintock Professor in the Department of Molecular Biology and Genetics in the College of Agriculture and Life Sciences, noted that BC200 was itself created from a mobile element but has retained its mobility and yet it is also clearly serving a cellular function. Somehow evolution hasn’t been able to untangle these two things.
In addition to its primary expression in neurons, the gene appears in low levels within germ cells—sperm and eggs—which gives it the theoretical potential to generate inheritable insertions elsewhere in the genome.
Uncovering the Poxvirus Insertions
The discovery of BC200 inside a virus dates back to work that began in 2010. Cheng Sun, then a postdoctoral researcher, was investigating human transposons in viral genomes using specialized software and genome databases while working in a joint lab at the University of Texas at Arlington. Sun identified two distinct insertions of BC200 inside the molluscum contagiosum virus, an infectious but largely benign human poxvirus responsible for causing warts.
Though the research team recognized the significance of finding a human jumping gene inside a viral genome, they did not publish the findings immediately. Years later, a conference meeting between Feschotte and Sun reunited the investigators. Sun and his graduate student Pu Gao resurrected the project, leading to publication in the journal Science. I can’t believe we never got scooped on this,
Feschotte remarked regarding the long gap before publication.
Investigators estimate that BC200 jumped into the molluscum contagiosum virus twice within modern human history, approximately 100,000 years ago since the era of Homo sapiens. Because molluscum contagiosum virus exclusively infects human skin cells, scientists suspect the genetic transfer occurred directly within cutaneous tissue.
Evolutionary Parallels and Cross-Species Spread
Documented cases of vertebrate transposable elements escaping into viruses in the wild remain exceedingly rare. In the late 1980s, researchers observed a transposon jumping from cultured moth cells into a baculovirus in a laboratory setting. Decades later, in 2007, a Japanese research group identified a transposable element embedded in a rodent poxvirus that originally derived from a snake, implying that the virus may have previously infected reptiles.
Feschotte described the initial moth cell observation as the first clear example of a transposon escaping its host genome to hop onto a virus. That early insight supported the hypothesis that if viruses cross species boundaries, they might serve as natural vehicles for spreading genetic elements between different organisms.
The persistence of BC200 demonstrates that evolution has no tidy process, leaving genes simultaneously essential to normal biology and inherently volatile.
Implications for Cancer and Brain Disorders
Beyond its normal physiological roles, BC200 exhibits aberrant behavior in pathological states. The gene is abnormally expressed in certain tumors and heavily overexpressed in the brains of Alzheimer’s disease patients, suggesting that its active jumping ability might directly contribute to disease progression or cellular dysfunction.
Researchers are now pursuing several lines of inquiry to understand the broader impact of this genetic oddity. Teams want to determine whether the molluscum contagiosum virus actively exploits BC200 to manipulate human host cells for its own survival. At the same time, scientists aim to clarify whether the gene continues to jump inside cancer cells, potentially triggering harmful mutations that drive tumor growth.