Naked mole rat queens use a smell to stay on top

Hello Nature readers,
Today we discover how naked mole rat queens keep an iron grip on their throne, investigate the origins of a cyclosporidia outbreak in the United States and consider whether it’s possible to end poverty without economic growth.

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How naked mole rat queens keep the throne

Naked mole rat (Heterocephalus glaber) queens produce a chemical that prevents other females in their colony from reproducing. The smell of isopropyl myristate — which is also a common ingredient in skincare products — alters the production of hormones in other females, which traps them in a prepubescent-like state. Researchers found that the chemical alone can maintain the status quo in mole-rat colonies when the queen is not physically present. The study solves the “longstanding mystery” of why only one female in a naked mole rat colony reproduces, says behavioural scientist Melissa Holmes.

Why astronauts waste away in space

Exposure to microgravity aboard the International Space Station causes mitochondria in human cells and C. elegans worms to produce fewer proteins. The effect seems to be caused by a disruption to cell adhesion — cells’ ability to stick together with proteins on their surface — caused by microgravity. The findings could help to explain why astronauts’ bone- and muscle-mass decreases after stints in space.

T-cell overdrive links virus to MS

Epstein-Barr virus (EBV) triggers a particularly strong immune response from a particular type of T cell, which hints at why the virus is implicated in the development of the autoimmune disorder multiple sclerosis (MS). Researchers found that the activity of CD4⁺ T cells in response to EBV was twice as high in people with MS compared to people without the condition, but responsiveness decreased markedly when CD4⁺ cells were depleted. A treatment that depletes B cells, the immune cells that EBV infects, also reduced CD4⁺ response, because the cells had fewer stimuli to respond to.

Scientists hunt Cyclospora source

Health officials in the United States are racing to pin down the origins of a widespread outbreak of the diarrhoeal disease cyclosporiasis. The parasite that causes the disease, Cyclospora cayetanensis, is difficult to trace because there’s a delay between consuming contaminated food and the appearance of symptoms, researchers say. The efforts are also complicated by cuts to health agencies made by the US government. “The number of staff working on these outbreaks is not what it used to be”, says Joel Barratt, former leader of the parasite surveillance team at the US Centers for Disease Control and Prevention.

How workable are plans for a better world?

Two recent major reports have laid out ways to move beyond growth for growth’s sake, in favour of focusing on making lives better and protecting the Earth. But not all economists think that these plans — which include ideas such as global taxes on the very rich — are realistic. Growth, they argue, has a proven track record of reducing extreme poverty, and large-scale redistribution of wealth will never fly politically. Or it might be a matter of fine-tuning, rather than ditching, growth. ‘Green growth’, for example, hinges on cleaner technologies, while ‘degrowth’ strategies involving simply producing and consuming less could be implemented at certain scales, such as in cities.

The houses built to burn down

In South Carolina, members of a non-profit organization are burning down houses on purpose. The group are studying how blazes tear through, and spread between, these custom-built casas to learn how to build homes that are more fireproof. As climate change makes wildfires ever more frequent, tweaks to the design of houses, and entire neighbourhoods, could limit the damage wrought by these destructive events, the team says.

‘My research on mice is distressing me’

What do you do if you love your research but not the difficult realities that come with experimenting on animals? Three researchers familiar with the work advise a PhD student grappling with this problem that emotional reactions are valid. “When students are mocked for showing emotion about animal research, that reflects a problem with the research culture,” says one of them, lab technician Fernando Gonzalez-Uarquin. Self-care strategies, such as getting enough sleep and disengaging from work each day, can help build resilience. And becoming more composed when conducting animal procedures doesn’t indicate a lack of empathy. “A calm and confident researcher handles animals better than a stressed one, which matters for animal welfare,” Gonzalez-Uarquin says.