Summary
Anthropic says Claude agents identified a previously uncharacterized enzyme system in bacteriophages, built around a known reverse transcriptase and an array of DNA repeats. Early laboratory experiments found that the array is expressed as distinct short RNAs, but the system’s function is still being investigated.
Anthropic says agents running Claude identified a previously uncharacterized enzyme system in bacteriophages, the viruses that infect bacteria. The company calls it array-associated reverse transcriptases, or ART. Its first laboratory experiments found that the system’s DNA repeat array is expressed as distinct short RNAs. The system’s biological function is still under investigation.
The system around the enzyme is the new finding
ART consists of a reverse transcriptase (RT), a neighbouring partner gene and a long array of evenly spaced DNA repeats. RTs copy RNA into DNA. The RT associated with ART had been identified in earlier studies; Anthropic’s reported discovery is the previously uncharacterized combination of that enzyme with the repeat array and partner gene.
The array’s layout resembles a CRISPR array. In CRISPR systems, arrays hold sequences that are transcribed into RNAs involved in directing the system to its targets. Anthropic says ART arrays also produce short RNAs, making the comparison biologically interesting. The shared feature is an array of repeats and the production of RNAs: the early findings do not establish that ART works like CRISPR or can be used for gene editing.
Anthropic reports that ART is found mainly in bacteriophages. Its researchers are now investigating what the system does. The company says systems with some of ART’s characteristics have, in other cases, been programmable and used for operations such as cutting, copying or pasting DNA. Whether ART has a comparable role remains an open research question.
How Claude surfaced the candidate
Anthropic formed a life-sciences research group and laboratory in 2026 to use Claude in biological research, including searching DNA datasets for uncharacterized protein families. For this search, the company says Claude agents gathered more than 200,000 reverse transcriptases, identified 3,500 candidate systems and narrowed them to 20 candidates for detailed analysis. The search took 21 hours and involved roughly 950 agents using 210 million tokens, according to Anthropic.
One agent examined DNA near an unusual RT and noticed a tandem repeat array. It then counted the repeats, assessed their spacing, compared the arrangement with known systems and searched for prior reports before submitting a candidate for human review. Anthropic says scientists provided the initial prompt, reviewed candidates and carried out all laboratory work; the AI agents performed the database search and analyses described in the announcement.
The result is an early example of AI-assisted genomic discovery: using computational search to flag an unexpected pattern for experimental follow-up. The short RNAs provide an initial clue about ART’s biology, while further experiments will be needed to determine the system’s function.