BC200: Human Jumping Gene Found In Poxvirus

A human gene that is both mobile and required for bodily functions wasn’t known to exist – until scientists found a human genetic element, BC200, in a poxvirus and discovered it is important for brain function and is a jumping gene capable of moving and inserting itself in genomes.  

The authors note that BC200 is mostly expressed in neurons and originated millions of years ago from a ‘jumping gene’, a non-coding genetic element known for its ability to move and insert itself in genomes. What science calls a transposon. Transposons account for half of human DNA, most of them are inactive, with a very small number of them remaining mobile and able to replicate within genomes.

Transposons can insert blocks of DNA in a gene and be a positive force, regulating or assembling new beneficial genes, or disrupt things and cause disease. When they are repurposed for cellular functions they are no longer transposable, but BC200 was created from a mobile element yet has retained its mobility while still clearly serving a cellular function. 

In a rarity, evolution did not untangle those two things. 

Though not in humans, there have been other cases of transposable elements in other species inserting in viruses, such as the insertion of a transposon from moth cells they were studying in culture to a baculovirus, known to infect insects. BC200 was discovered in the 1980s and is only in humans and our primate cousins, classified as plentiful non-coding RNA in human neurons. It is also expressed in some tumors and overexpressed in the brains of Alzheimer’s disease patients. BC200’s physiological function is still poorly understood but the assumption is it works in the translation of neuronal messenger RNAs into proteins. Since it is also found in low levels in germ cells (sperm and eggs) it can potentially generate inheritable insertions in other areas of the genome.

The researchers believe that it jumped in skin cells, since they are the only cells known to be infected by molluscum contagiosum virus (MCV). Next up is to see if the molluscum contagiosum virus is using BC200 for its own purpose of manipulating human host cells, and perhaps learn if it is jumping in cancer cells and causing mutations.

Citation: Pu Gao, Ellen J. Pritham, Cedric Feschotte, and Cheng Sun, Escape of the BC200 gene to a human poxvirus reveals its persistent transposition in primates.Science393,1342-1346(2026).DOI:10.1126/science.aeh3441

Graphic: By Jfratzke – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=63854113