Researchers in China have edited the genes of human embryos to make cells resistant to HIV infection. It’s the second reported case of using molecular scissors called CRISPR/Cas9 to alter genes in human embryos. In the new work, published April 6 in the Journal of Assisted Reproduction and Genetics, the researchers snipped a gene called […]

Iron, says aging expert Naftali Raz, is like the Force. It can be good or bad, depending on the context. When that context is the human brain, though, scientists wrangle over whether iron is a dark force for evil or a bright source of support. Some iron is absolutely essential for the brain. On that, […]

In case there were any lingering doubts, three new studies published May 11 could cement the theory that Zika virus infection in utero causes birth defects. One shows that mice engineered to be susceptible to Zika can pass the virus to offspring via the placenta. In these pregnant mice, which have severely crippled immune systems, […]

A new study sounds a cautionary note for a controversial procedure used in creating “three-parent babies.” That procedure replaces defective mitochondria, the energy-generating organelles in cells, with healthy ones. But even a tiny amount of defective mitochondria may replicate and take over the cell, researchers report online May 19 in Cell Stem Cell. Exactly which […]

A “dirty blizzard” bombarded the Gulf of Mexico seafloor with pollution from the 2010 Deepwater Horizon oil spill for months after workers sealed the leak, new research shows. Marine snow, an organic material that floats down from the ocean’s upper layers, carried the pollution to the seafloor, researchers report the week of May 30 in […]

AUSTIN, TEXAS — Cities have become great unintentional experiments in evolution. Urban life can alter the basic biological traits of its plant and animal residents, down to the taste of leaves or the stickiness of toes, researchers reported at the 2016 Evolution conference. For white clover (Trifolium repens), leaf taste matters as a defense against […]

‘Hearing’ electrically — A deaf person has been able to “hear” as a result of direct electrical excitation of auditory nerve fibers. But what he can hear may not make much sense…. Although speech-modulated stimuli were not understood, they were unerringly recognized as speech, mainly by rhythm and volume cues…. Optimism about the possibility of […]

ORLANDO, FLA. — What some people view as a flaw in a new genetic-engineering tool might actually be a safety feature, a study suggests. CRISPR/Cas9 gene drives, as the new tools are called, are molecular cut-and-paste machines that can break regular rules of inheritance and get passed to more than 50 percent of offspring (SN: […]

As happens every summer, sea ice in the Arctic is shrinking as temperatures warm. But this year is a particularly warm year, and there is less sea ice than there usually is. Scientists say Earth is on track to matchor perhaps even exceed the record low extent of summertime sea ice seen in September 2012. […]

On December 3, 2000, at Cape Shirreff, near the tip of the Antarctic Peninsula, a female Antarctic fur seal experienced a personal tragedy: She gave birth to a dead male pup. For the next day or so, the seal, numbered “12” by scientists watching her group, nuzzled her baby and vocalized to him. Nearby on […]