In response to pheromone(s), Caenorhabditis elegans interrupts its reproductive life cycle and enters diapause as a stress-resistant dauer larva. This decision is governed by a complex system of neuronal and hormonal regulation. All the signals converge onto the nuclear hormone receptor DAF-12. A sterol-derived hormone, dafachronic acid (DA), supports reproductive development by binding to DAF-12 and inhibiting its dauer-promoting activity. Here, we identify a methyltransferase, STRM-1, that modulates DA levels and thus dauer formation. By modifying the substrates that are used for the synthesis of DA, STRM-1 can reduce the amount of hormone produced. Loss of STRM-1 function leads to elevated levels of DA and inefficient dauer formation. Sterol methylation was not previously recognized as a mechanism for regulating hormone activity. Moreover, the C-4 sterol nucleus methylation catalyzed by STRM-1 is unique to nematodes and thus could be a target for therapeutic strategies against parasitic nematode infections.

A “safety signal” in a similar respiratory syncytial virus (RSV) vaccine has led to trials being stopped and prompted calls for a cautious approach to using the vaccine in pregnant women, reports Hristio Boytchev

Germany is experiencing a slow uptake of the Oxford AstraZeneca covid-19 vaccine, latest figures show. Data up to 1 March show that of the 1 452 000 doses delivered to the country, a little over a third, (514 426) had been used. 1

Covid-19: Why the Balkans' vaccine rollout lags behind most of Europe Europe's successful vaccine rollout has not extended to the east of the continent. Hristio Boytchev asks what's been holding the Balkan countries back Hristio Boytchev freelance journalist

lin, came to Germany from Mexico more than 35 years ago. "I wanted to study in Europe, and Germany seemed like an interesting place, especially Berlin, " he says. "I came to do my PhD at the Free University but never planned to stay here. " However, before even completing his doctorate, Rojas was hired by the GMD National Research Center for Information Technology to work on machine learning. "One contract led to another, and before you realize, you've built your career in another country. " A lot has changed since Rojas arrived in West Germany in 1982, a country that would exist only for another seven years until the fall of the Berlin Wall. "There were not many researchers from other countries [back then]; that has changed now, " he says. Germany offers a vast and varied research landscape, with more than 1,000 public and