Level 1 — Absolute Beginner
Scientists found a gene with a double life. Its name is BC200.
BC200 works in brain cells. It helps nerve cells do their job.
But BC200 also came from a jumping gene. A jumping gene can move to new places in DNA.
Most jumping genes that get a job stop moving. BC200 may still move. The scientists also found copies of BC200 in a virus.
- gene
- A part of DNA that carries instructions for the body.
- brain
- The body part you think with.
- cell
- The smallest living part of the body.
- DNA
- The code of life inside cells.
- jump
- To move quickly to a new place.
- virus
- A tiny germ that can make people sick.
- copy
- Something made to be the same as another.
- scientist
- A person who studies nature.
Level 2 — Elementary
A study in the journal Science, published on September 24, describes a human gene with a remarkable double life. The gene is called BC200.
BC200 is mostly active in neurons, the nerve cells of the brain. But it began millions of years ago as a transposon, also called a jumping gene, a piece of DNA that can copy itself and land in new places.
Usually, when a jumping gene is taken over for a job in the body, it loses its ability to move. Researchers say no one had seen a human gene that is both useful and mobile.
The team studied primate genomes and found that BC200 has made many new copies over time. They also found versions in some people but not in others, and two copies inside a human poxvirus.
- journal
- A magazine that publishes scientific studies.
- neuron
- A nerve cell.
- transposon
- A piece of DNA that can move around a genome.
- mobile
- Able to move.
- genome
- All the DNA of a living thing.
- primate
- An animal such as a monkey, ape or human.
- version
- A different form of something.
- poxvirus
- A kind of virus that causes pox diseases.
Level 3 — Intermediate
In a study published September 24 in the journal Science, a team led from Cornell University reported that a human gene called BC200 combines traits never before seen together. It is switched on mainly in neurons, yet it traces back to a transposon, a so-called jumping gene that copies itself into new spots in the genome.
"Genes that come from transposable elements and that are repurposed for cellular functions are typically no longer transposable," said Cedric Feschotte, a senior author of the study. BC200 appears to break that rule.
By comparing primate genomes, the researchers showed that BC200 has repeatedly created new copies over evolutionary time, leaving hundreds of insertions unique to particular lineages. They also found insertion variants present in some humans but absent in others, including very recent ones, which suggests the gene may still be moving today.
The team also discovered two independent copies of BC200 inside a human poxvirus, a sign that the gene was captured and carried by a virus. Why a brain gene would turn up in a pathogen remains an open question.
- traits
- Characteristic features.
- repurposed
- Adapted for a new use.
- transposable
- Able to move within DNA.
- evolutionary
- Relating to gradual change in living things over time.
- lineage
- A line of descent from common ancestors.
- insertion
- A piece of DNA added at a new location.
- independent
- Not connected or depending on another.
- pathogen
- A germ that causes disease.
Level 4 — Advanced
A gene that helps run the human brain turns out to have a restless past, and possibly a restless present. In a study published September 24 in Science, researchers led from Cornell University describe BC200 as a gene with a combination of traits never previously observed: it is expressed chiefly in neurons, yet it descends from a transposon, a jumping gene, and appears to have retained the ability to mobilize.
The finding cuts against a standing assumption. "Genes that come from transposable elements and that are repurposed for cellular functions are typically no longer transposable," said Cedric Feschotte, a senior author. Domesticated transposons are usually immobilized, much like a tamed animal that no longer roams.
Comparative analysis of primate genomes showed that BC200 has repeatedly seeded new copies over evolutionary time, yielding hundreds of lineage-specific insertions. The researchers also identified insertion variants that exist in some humans but not in others, including very recent, individual-specific ones, consistent with ongoing transposition.
Adding an unexpected twist, the team found two independent copies of BC200 in a human poxvirus, implying that the gene was somehow captured by the virus. The authors leave open what the arrangement means for either party, but the discovery underlines how porous the boundary between host genes and mobile elements can be, and how much of the human genome may still be in motion.
- restless
- Unable to stay still or settled.
- expressed
- Active, in the sense of producing its product in a cell.
- mobilize
- To become able to move or act.
- domesticated
- Adapted for human or cellular use, as if tamed.
- immobilized
- Prevented from moving.
- comparative
- Based on comparing things.
- seeded
- Spread new copies of something.
- porous
- Allowing things to pass through.