The thymus disappears as we age — can it be regrown?

Hello Nature readers,
Today we find sugar in the stars, explore efforts to regrow the thymus and speak the name of an important Maya mathematician-astronomer for the first time in ages.

If you enjoy this newsletter, please consider recommending it to a friend or colleague. Click here to forward it by e-mail. Thank you!

First sign of life-boosting ‘space sugar’

Astronomers have detected a four-carbon sugar molecule in a cloud of gas and dust near the centre of our galaxy. The molecule, erythrulose, is the most complex sugar detected outside of our Solar System, the team says. If erythrulose exists in these molecular clouds, it could be transferred to passing asteroids and comets as a star system forms. Such bodies could have brought sugars — the feedstock for early versions of DNA and RNA — to Earth during a period of heavy asteroid bombardment around four billion years ago, suggests astronomer and study co-author Izaskun Jiménez-Serra.

Nurture, not nature, creates handedness

Researchers taught people to write with their elbows to show that practice helps to make people left- or right-handed, not just the innate preference. People with pens taped to their arms wrote no better or worse on their dominant and non-dominant sides, the team found. And training helped them to improve, regardless of which side they used. “The dominant arm isn’t more capable because one hemisphere of the brain is simply better at controlling movement,” says neurologist and study co-author Ahmet Arac. “It is because we've spent a lifetime practicing the specific, complicated movements that tools and handwriting demand.”

Maya glyph names maths powerhouse

A mathematical formula inscribed on a wall at the Maya site of Xultun in Guatemala has revealed the name of an important Maya mathematician-astronomer. Sak Tahn Waax, or ‘White-Chested Fox’, was a scholar comparable with mathematical giants of the past, researchers suggest. The calculations inscribed in this set of hieroglyphs expresses the relationships between several calendar systems in a playful manner that hasn’t been seen before in Mayan texts, says archaeologist and study co-author Heather Hurst. “I think it was a mathematical flex,” she says.

The race to regrow a disappearing organ

The past three years has seen a boom in research into the thymus — a peculiar immune organ that atrophies and practically disappears as people age. Once thought dispensible, some studies now report that a person’s thymus health is a probable indicator of their overall health. These findings have been followed by a flood of investment into potential therapies to regenerate the thymus, which might help to slow ageing and prevent cancer.

Summer reads: hot books for long nights

It’s summer where I am, but wherever on the globe you dwell, it’s never the wrong season for a good book. Nature invited ten contributors to share their current book obsessions, including a book on water that “breathed life” into the vocation of space environmentalist Moriba Jah; and AI researcher Blaise Agüera y Arcas’s choice that introduces the “quietly radical” argument of naturalist Jean‑Baptiste Lamarck: “life is not merely shaped by external forces, but is actively, continuously involved in its own making”.

Epigenetic editors tune gene expression

Researchers are increasingly targeting specific epigenetic markers — chemical groups that sit on DNA and the proteins that it winds around — to explore the intricacies of gene expression and develop therapies. Compared with gene editing, “I find epigenome editing to be much more sophisticated, much more complex,” says biomedical engineer Charles Gersbach. “There are just so many more things that you can do with epigenome editing that aren’t necessarily doable with genome editing.”