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Coloured light micrograph of a sperm cell (small, with a long tail) approaching an egg cell (much larger, roughly circular) on a green background.

A sperm cell (right) swims towards a human egg (artificially coloured).Credit: AJ Photo/Science Photo Library

Lab-grown sperm and eggs: a key step closer

Researchers have discovered a protein that promotes an ‘epigenetic’ reset in human cells — a small but crucial step in their development into sperm or eggs. The epigenome affects whether genes are turned on or off, and helps to differentiate, for example, a brain cell from a liver cell. The cells in the study stopped developing further after epigenetic reprogramming, so before we can grow eggs and sperm in a dish, “there is still much work to be done and considerable time required”, says reproductive epigeneticist Fan Guo.

Nature | 4 min read

Reference: Nature paper

First ‘bilingual’ brain-reading device

An AI-powered brain implant has helped, for the first time, a paralysed bilingual person speak in both their languages. An artificial intelligence (AI) system decodes the man’s neural patterns and interprets the language he’s using — English or his native Spanish — based partly on which combination of words makes the most sense. “What languages someone speaks are actually very linked to their identity,” says neurosurgeon and study co-author Edward Chang. “Our long-term goal has never been just about replacing words, but about restoring connection for people.”

Nature | 5 min read

Reference: Nature Biomedical Engineering paper

The body odours that attract mosquitos

An ambitious field trial in Zambia investigated why mosquitoes seem to find some people more appetizing than others. Researchers invited volunteers into individual sleeping pods that were connected to a giant mosquito enclosure housing the mosquito Anopheles gambiae, which transmit deadly malaria. Infrared cameras tracked the mozzies’ movements and found they were most attracted to people whose scents were “enriched for a class of molecules called airborne carboxylic acids, and also other compounds that are produced by the bacteria that live on our skin”, says biologist and study co-author Conor McMeniman. The findings could be used to develop more-effective repellents, he says, “but also potentially turn the mosquito’s sense of smell against them, by engineering synthetic blends to lure mosquitoes into traps for mass control purposes.”

CNN | 6 min read & Nature Africa | 4 min read

Reference: Current Biology paper

An aerial view of a large mosquito enclosure connected by tubes to small sleeping pods, all surrounded by a natural landscape.

The mosquitos inside a tennis-court-sized cage didn’t carry the malaria parasite and couldn’t get at the people sleeping in surrounding pods, but could smell them. (Macha Research Trust)

Features & opinion

Scientists facing harassment need support

Scientists are facing more harassment, both online and face-to-face. But there is debate about how to protect them. “The most important thing really is that people feel like their institution supports them,” says public-health researcher Tara Kirk Sell, who advised the Johns Hopkins Bloomberg School of Public Health on how to protect its staff from pandemic-related abuse. The challenge is connecting them to that protection quickly and easily, she says. Institutions must grapple with whether to remain politically neutral when attacks are drummed up by one extreme of the political spectrum. In that case, neutrality “favours the tormentors”, argues paediatrician and virologist Peter Hotez, a high-profile advocate for the benefits of vaccinations. “More often than not, the scientists are kind of hung out to dry.”

Nature | 10 min read

Exploitation of the high seas must end

The high seas hide many sins, from modern-day slavery onboard fishing boats to a graveyard of decommissioned satellites. And more are looming, such as destructive deep-sea mining. In her new book, science journalist Olive Heffernan documents how a few powerful people are capitalizing on the absence of governance of the open oceans. Heffernan’s must-read text “takes even the most landlocked out to sea”, write reviewers and marine biologists Diva Amon and Juliano Palacios Abrantes. At the same time, as scientists from lower-income countries, they “wish that the book had avoided perpetuating one of the main issues plaguing discourse surrounding the high seas: a lack of representation and inclusion”.

Nature | 6 min read

Anxiety treatments tailored to young brains

In adolescents, brain regions involved in processing and remembering emotional experiences — the amygdala and the hippocampus — are activated at a higher level than in adults. But the part that regulates these feelings, the prefrontal cortex, doesn’t reach peak activity levels until adulthood. That difference might have once helped young adults achieve reproductive success by being tuned into emotional and social information. Today, it could be one reason why some teenagers feel overwhelmed by it, write neuroscientists BJ Casey and Heidi Meyer. They are developing treatments for anxiety that are tailored to the developing brain by relying less on the prefrontal cortex, such as ‘rewriting’ an anxious memory or using a ‘safety cue’ that signals all is well.

Scientific American | 11 min read

Image of the week

A cross section of a mouse eye with concentric circles and a graphically similar photo of Saturn’s north pole

NASA visualization scientist Kimberly Arcand has constructed a photo essay comparing microscopic images of biological phenomena, such as this mouse retina, to macroscopic images from celestial phenomena such as Saturn’s north pole. These “size doppelgangers”, she writes, allow people to “begin to explore the true scale of science”. (Micro Macro blog | leisurely scroll) (Bryan William Jones and Robert E. Marc, University of Utah / NASA/JPL-Caltech/SSI/Hampton University)


“There is no financial compensation for highlighting errors, and doing so can see people marked out as troublemakers.”

Borrowing the idea of ‘bug bounties’ from the technology industry could provide a systematic way to detect and correct the errors that litter the scientific literature, argues psychologist Malte Elson. (Nature | 5 min read)