While the Discovery Channel's annual shark week event has given the public more familiarity with the species, there is much about sharks—from their mysterious love lives to how their eating habits bring them into conflict with recreational anglers—that remains a mystery to scientists. Now, two new studies led by researchers from the University of Massachusetts Amherst peer into these important aspects of shark biology to help guide real-world conservation strategies.

Cysteine is the only protein-building amino acid that is acutely toxic to human cells when present in excess. Cells avoid this toxicity by converting cysteine into glutathione. Scientists had long puzzled over why excess cysteine is dangerous, while a large amount of glutathione is safe. A new study shows that excess cysteine causes the release of iron, which accumulates inside mitochondria and ultimately triggers cell death. Glutathione gives the cell many of the same advantages as free cysteine, without unleashing unsafe levels of iron. Beyond clarifying fundamental mysteries underlying the basic biology of human cells, the findings may also have implications for cancers that take up large amounts of cysteine.

Insect ‘detectives’ have discovered two new types of large stick insects, showing scientists are still uncovering new species in some of Australia’s most well-studied landscapes.

Cell division, a process fundamental to life, still holds surprises. Researchers from the University of Zurich and the Spanish National Cancer Research Centre (CNIO) have discovered a key mechanism that allows cells to protect genetic information as they divide.

The discovery centres on cohesin, a key protein involved in genome folding inside the cell nucleus.

Understanding this basic cellular process could have implications for precision oncology, as many cancer therapies work by triggering the very errors that this mechanism prevents.

A new study integrating fossil, distributional and molecular evidence traces the evolutionary history of marmots back to North America and reveals how geological and climatic changes drove their dispersal and diversification. Published in Journal of Systematics and Evolution