Editorial collection
Unexpected, visual, and carefully checked scientific facts — from the length of DNA to the remarkable machinery of living cells.
6 articles
01An ancient retroviral gene helps human placental cells fuse into a continuous layer. Studies of syncytin reveal how molecular machinery once used by viruses became part of mammalian development, with genetic experiments in mice providing further evidence of its importance.
02Laboratory rats learned to play hide-and-seek with humans, switching roles and selecting hiding places. Some even hid again after being found, delaying their playful reward. Two studies reveal how the animals behaved and how their brains tracked the game.
03Alaskan wood frogs remained frozen for an average of 193 days and survived temperatures as low as −18.1°C. High tissue glucose levels, possibly built up through repeated freeze–thaw cycles, may help protect them.
04The reflective layer behind a reindeer’s retina is gold-turquoise in summer but turns deep blue in winter. The change comes from a reorganization of collagen fibres that tunes this biological mirror to Arctic twilight.
05Bernhard Zondek helped turn early pregnancy from a clinical suspicion into a laboratory finding. His mouse bioassay detected hormonal activity in urine and established the principle behind modern pregnancy tests.
06Almost every human cell contains about two metres of DNA. How does the cell pack this enormous molecule into a microscopic nucleus while keeping the right genes accessible?
