About 950 AI agents spent 21 hours going through more than 200,000 enzymes that copy RNA into DNA.
The system consists of an enzyme, a partner gene, and a long array of repeats in the DNA. Its structure resembles CRISPR.
Lab experiments show that the array of repeats is expressed as several short RNA molecules, which also happens in CRISPR systems.
The AI company Anthropic has launched its own life sciences research group and lab. Among the first results is a previously unknown system of genes in viruses that infect bacteria. The system resembles CRISPR in its structure. The researchers do not yet know what it does.
The researchers call the system ART, short for array-associated reverse transcriptase. The finding is described in a preprint that has not yet been peer reviewed.
950 agents in 21 hours
The researchers gave the AI model Claude an initial instruction. It was to look for new reverse transcriptases in a large database of DNA sequences. A reverse transcriptase is an enzyme that copies RNA back into DNA. Bacteria often use such enzymes to defend themselves against viruses.
The database contained 1.9 billion protein clusters. About 950 AI agents worked for 21 hours without humans directing them. They collected more than 200,000 reverse transcriptases and identified about 3,500 possible systems. Finally, they selected 20 candidates and wrote a report on each one for the researchers.
According to Anthropic, this type of analysis can take an expert weeks or months.
The agent spotted the pattern on its own
ART turned up on a tangent. An agent was reading the raw DNA code next to an unusual enzyme. It wrote that it could see an array of repeats by eye. The agent counted the repeats, measured the distances between them, and compared them with known systems. Then it searched the scientific literature. When it found no earlier description, it sent a report to the researchers.
The enzyme itself was already known from a large bacterial virus, a so-called jumbo phage. The first description of the virus's genome mentioned the enzyme but not the repeats or the partner gene. Claude appears to be the first to see them.
The researchers also examined what happened inside the model as it read the sequence. Two internal signals reacted to the repeats just before the agent described them.
A structure that resembles CRISPR
ART consists of three parts. These are a reverse transcriptase, a gene next to it that makes a partner protein, and a long array of evenly spaced repeats in the DNA. The array contains between 3 and 21 copies of a short repeat. The gaps between the repeats are several times longer than in CRISPR. The system lacks the cas genes found in CRISPR systems.
The researchers found 95 groups of such enzymes in jumbo phages and in predicted viral genomes. Of these, 28 had an array of repeats in front of the enzyme's gene.
In CRISPR, the array of repeats is copied into RNA. That RNA makes the systems programmable. According to Anthropic, only a handful of known systems share these features with ART, and all of them can cut, copy, or paste DNA. We have previously written about a baby who was saved by the world's first personalized CRISPR treatment.
Up to 8 percent of the virus's RNA
The researchers analyzed published data from the virus SA1, which infects the bacterium Staphylococcus lentus. Fifteen minutes after infection, up to 8 percent of the virus's RNA came from the ART system's array of repeats.
When the researchers introduced the system into the bacterium E. coli, several short, separate RNA molecules formed. They resembled the ones that form when the virus infects its host. The researchers suggest that ART uses a set of different RNA molecules rather than a single one. They have not yet shown that the enzyme is active or what the system does for the virus.
Worth investigating further
Feng Zhang at MIT and the Broad Institute is one of the researchers behind CRISPR technology. He has read the preprint. He says the work is an example of how AI agents can contribute to biological discovery. According to him, the finding of RNA repeats linked to reverse transcriptases is interesting and worth investigating further.
Humans do the lab work
Anthropic started the research group in the spring of 2026. The lab is located in the San Francisco Bay Area and works at biosafety levels 1 and 2. Human researchers do all the lab work. Claude searches through DNA data, checks its methods against published results, writes reports on candidates, and reviews the evidence. The candidates that the researchers select are then tested in the lab.
WALL-Y
WALL-Y is an AI bot created in Claude. A human selects the news, WALL-Y writes the text and a human checks the results before publishing.