Hello Nature readers,
Today we learn that genes can have opposite effects depending on which parent they’re inherited from, discover a supplement that can reverse Alzheimer’s in mice and meet the teenage mathematician who disproved a 40-year-old conjecture.

Genes effects vary by parent-of-origin

The effect of a gene can vary greatly — and sometimes be the complete opposite — depending on which parent it’s inherited from. A team of researchers have devised a statistical model that has revealed at least 30 of these parent-of-origin effects in 14 genes, all without needing genomic data from a person’s parents. Nineteen gene variants had a ‘bipolar effect’, meaning it had opposite effects depending on which parent it came from. One such variant increased the risk of developing type 2 diabetes by 14% when inherited from the father but decreased it by 9% when inherited from the mother.

Royal Society shakes up publishing model

The UK Royal Society is converting eight of its ten journals to a ‘subscribe to open’ publishing model from next year. Under the model, article processing charges (APCs) — fees that authors pay to make their papers published open access — will be waived for these journals, and all content published that year will be free to access — as long as enough libraries commit to paying an annual subscription fee. Without sufficient subscriptions for 2026, the Royal Society will continue to offer APCs-based open-access options, and try again in 2027.

An LLM to call your own

A powerful new large language model (LLM) released by OpenAI is the first to live up to the company’s name — it’s the firm’s first ‘reasoning’ artificial intelligence that researchers can download and customize. Known as gpt-oss, the LLM is available in two sizes, both of which can be run locally and offline — the smaller of them on a single laptop — rather than requiring cloud computing or an online interface. This means they can be used to analyse, or be trained further on, sensitive data that can’t be transferred outside a given network.

A lithium a day could keep Alzheimer’s away

Replenishing the brain’s natural stores of lithium can protect against, and even reverse, Alzheimer’s disease in mice. Researchers found that in human brain tissue and mice, a decline in lithium concentration in the brain is linked to memory loss and the neurological hallmarks of Alzheimer’s — protein build-ups called amyloid plaques and tau tangles. The team found that these neurological changes were reversed in mice given a supplement containing a compound called lithium orotate. The molecule also restored the brain to a younger, healthier state and rolled back memory loss.

AI stumbles over bad benchmarks

To determine which artificial intelligence tool is best at a particular task, you can use a benchmark — a test that can be used to compare the performance of different models. For that system to work, benchmarks need to be robust. That, machine learning researchers say, is where things fall down. Increasingly, artificial intelligence models are being designed to compare favourably against benchmark tests. That process yields tools that pass the tests, but do little else, flooding researchers with tools that aren’t fit for purpose.

The teen who took maths by storm

In February, a preprint made waves in the world of mathematics by disproving the four-decade-old Mizohata-Takeuchi conjecture. Its author? 17-year-old Hannah Cairo. Cairo began to attend summer programs and classes at the University of California, Berkeley at just 14. It was there, working with mathematician Ruixiang Zhang, that she cracked the conjecture. Having already made her mark on mathematics, Cairo is headed for graduate school — without attending college, or even finishing high school. But she hasn’t let her success go to her head. “It looks like mathematically I’m, like, whatever,” she says.