Hello Nature readers, would you like to get this Briefing in your inbox free every day? Sign up here

Three sleeping baby mice curled up together in a nest.

Only a few of the embryos derived from all-male cells went on to develop into healthy mouse pups.Credit: Ciobaniuc Adrian Eugen/Alamy

The mice with two biological fathers

Researchers have made eggs from the cells of male mice — and shown that, once fertilized and implanted into female mice, the eggs can develop into seemingly healthy, fertile offspring. The approach, announced yesterday at the Third International Summit on Human Genome Editing in London, has not yet been published and is a long way from being used in humans. It is an early proof-of-concept for a technique that raises the possibility of a way to treat some causes of infertility — and even allow for single-parent embryos.

Nature | 5 min read

Throat neurons send sickness signal

Special neurons in the throats of mice notify the brain of an influenza infection, triggering behavioural changes, such as decreased movement and feeding. The throat cells contain a receptor for prostaglandins — chemicals that are made in infected tissues — and can tell the brain exactly where an infection is occurring. Before the “paradigm-shifting” study, it was unclear exactly how the brain became aware of sickness in the body. The work “flips previous thinking on its head”, says sensory biologist Ishmail Abdus-Saboor. More such dedicated neural pathways could exist, including ones that detect gut infections and trigger nausea.

Nature | 4 min read

Reference: Nature paper

US hearing renews COVID lab-leak debate

Yesterday, the US House of Representatives kicked off the first in a series of public hearings that aim to investigate whether the SARS-CoV-2 coronavirus arose arose from contact between people and animals or leaked from a laboratory in China. But the hearing contained more political theatre than discussion of scientific evidence. Republican committee members pushed the idea that public-health leader Anthony Fauci tried to quash investigations into a lab leak, while Democrats questioned the credibility of a witness. “I’m very much concerned that people are allowing themselves to be guided by their emotions, intuition and historical precedence,” says microbiologist David Relman.

Nature | 7 min read

French institute severs ties with China

The influential Pasteur Institute in France will cease to co-lead an infectious-disease institute in Shanghai that it established in 2004 in partnership with the Chinese Academy of Sciences. What initiated the break-up isn’t clear. Some researchers think it reflects a larger trend of China ending an era of internationalization. Others think it simply an individual case and will have minimal impact on virology research in China, which is now one of the country’s strengths.

Nature | 4 min read

DNA from coastal sediment turns back time

Environmental DNA extracted from marine sediment has given scientists a blow-by-blow account of 200 years of habitat destruction in Italy’s Bagnoli Bay. The technique reveals how construction in the nineteenth century of steelworks, an asbestos plant and a causeway led to the disappearance of seagrass meadows and the marine life that depended on them, even though no ecosystem surveys were conducted at the time. “This is a very powerful tool,” says aquatic ecologist Eric Capo.

Hakai | 3 min read

Reference: Environment International paper

How wildfires shred the ozone layer

Huge wildfires that raged across Australia in 2019–20 unleashed chemicals that chewed through the ozone layer. The wildfire smoke combined with harmless remnants of now-banned chlorinated compounds, reactivating their ozone-eating form — a reaction that doesn’t usually happen in the warm air away from the poles. More-frequent wildfires resulting from climate change could expand and prolong the hole in the ozone layer, which protects Earth from harmful ultraviolet rays.

Nature | 4 min read

Reference: Nature paper

Infographic showing a cloud form when a wildfire rises into the stratosphere.

Smoke particles from intense wildfires can enter the stratosphere, where they can absorb hydrogen chloride (HCl) gas, derived mostly from the breakdown of anthropogenic chlorofluorocarbon compounds (not shown). This allows the particles to catalyse the conversion of other chlorine-containing gases, such as chlorine nitrate (ClONO2) and hypochlorous acid (HOCl), to ‘photoreactive’ chlorine compounds. When irradiated by ultraviolet light from the Sun, the photoreactive compounds produce chlorine radicals that catalytically destroy ozone, depleting its concentration in the stratosphere. (Nature News & Views | 7 min read, Nature paywall)

Features & opinion

‘Digital twins’ test food systems to the limit

How do COVID-19 restrictions affect harvests in sub-Saharan Africa, and how will Germany’s move away from Russian gas influence fertilizer production? Questions about how food systems respond to shocks can be explored with ‘digital twins’ — models that are hooked up to real-world data about food production, transport, processing and consumption. Most of this information already exists, says food-systems scientist Zia Mehrabi. Now it’s a question of putting together the pieces. “With real-time insights, we could see key fragilities in food systems before it’s too late,” he says.

Nature | 5 min read


An illustration of woman standing under a kidney-shaped tree. The tree leaves have fallen and are blown away by wind.

Credit: Eva Vazquez

Chronic kidney disease

Today is World Kidney Day, raising awareness of the organ that filters all of the blood in the body every 30 minutes.

• This round-the-clock removal of toxins is hard work, and over a lifetime of purification, these vital organs can falter. The result is a progressive condition — chronic kidney disease (CKD) — which affects roughly 10% of the world’s population and has become one of the leading causes of death worldwide. The stakes are high, and research is advancing on multiple fronts. (7 min read)

• A class of drugs originally developed to treat type 2 diabetes, known as SGLT2 inhibitors, has arrived on the scene over the past three years and haves provedn highly effective at slowing the loss of kidney function. Multiple clinical trials have been halted early because the drugs’ efficacy was so obvious. (11 min read)

• Around 10% of adult cases of CKD can be traced to genetic mutations. Research to pin down that genetic link is changing how the disease is diagnosed and treated. (8 min read)

• Some researchers are building simplified versions of kidneys in the lab to better understand how these highly complex organs work — and how they go wrong in CKD. Such organoids, which derive from stem cells, are proving useful in modelling kidney development and disease. (9 min read)

• CKD hits people without access to good health care the hardest. Most people with the condition eventually need dialysis and, ultimately, a kidney transplant — lifesaving therapies that are expensive and not always easily available. (9 min read)

• That inequity is felt especially hard for people with CKD that has developed as a result of diabetes. In the United States, non-citizens are, in many cases, prohibited from receiving transplants — they are, however, permitted to donate their own organs. (8 min read & 5 min read)

• When drugs, conventional dialysis and transplants are out of reach, technology under development could offer a solution: portable or implantable machines that replicate the kidneys’ functions. (9 min read)

Nature Outlook: Chronic kidney disease is an editorially independent supplement produced with the financial support of Bayer AG.

Quote of the day

“My family expected me to have a highly regarded oil-company job, one of the most prestigious and high-paying professions in my country. But I had already fallen in love with palaeontology.”

When Khalafallah Salih chose his field, it was not possible to study in Sudan or even abroad by obtaining a government scholarship. Now he’s back in his homeland, trying to connect Sudanese people to the country’s deep history. (Nature | 6 min read)