Loose pieces of DNA course through our veins. As cells in our body die, they cast off fragments of genes, some of which end up in the bloodstream, saliva and urine.

Cell-free DNA is like a message in a bottle, delivering secrets about what’s happening inside our bodies. Pregnant women, for example, carry cell-free DNA from their fetuses. A test that analyzes fetal DNA has proved to be more accurate in screening for Down syndrome than standard blood tests.

In 2012, Jay Shendure, a geneticist at the University of Washington, and his colleagues were able to reconstruct the entire genome of a fetus from cell-free DNA in a pregnant woman’s saliva.

Continue reading “Searching for Cancer Maps in Free-Floating DNA” →

The Fish and Wildlife Service is barring the door against 201 species of salamanders, making it illegal to import them or move them across state lines, the agency  announced on Tuesday. Scientists hope the ban will help prevent a devastating outbreak from driving native salamander species extinct.

In 2013, scientists in the Netherlands discovered a species of fungus infecting native fire salamanders. Later research revealed that the fungus, called Batrachochytrium salamandrivorans, or Bsal, was carried by Asian salamanders that were imported into Europe as pets. While the fungus was harmless to the Asian amphibians, it was lethal to the Dutch ones.

Continue reading “U.S. Restricts Movement of Salamanders, for Their Own Good” →

Narwhals and newts, eagles and eagle rays — the diversity of animal forms never ceases to amaze. At the root of this spectacular diversity is the fact that all animals are made up of many cells — in our case, about 37 trillion of them. As an animal develops from a fertilized egg, its cells may diversify into a seemingly limitless range of types and tissues, from tusks to feathers to brains.

The transition from our single-celled ancestors to the first multicellular animals occurred about 800 million years ago, but scientists aren’t sure how it happened. In a study published in the journal eLife, a team of researchers tackles this mystery in a new way.

Continue reading “Genetic Flip Helped Organisms Go From One Cell to Many” →