Nearly 80% of U.S. dairy cows have their horns removed each year to protect their handlers and fellow cattle. But the practice, which is both painful and expensive, has come under increasing scrutiny from animal rights activists. Now, science may be coming to the rescue: A group of researchers announced last week that they successfully edited the genomes of dairy cows to make them hornless. The scientists used the transcription activator-like effector nucleases DNA editing technique to introduce a natural allele linked to hornlessness into dairy cow embryos. Five healthy calves were born, all without horns (above, left), the researchers report in a letter in Nature Biotechnology. The allele - called POLLED - is much more common in beef catt ...

It has to do with a single gene! More than a decade ago, researchers discovered that one gene (MC1R) on chromosome 16 plays an important role in giving people red hair. MC1R task is to make the protein melanocortin 1. This protein plays an important role in converting red pigment into black pigment. If you end up with only one mutated MC1R gene, red hair can appear in unwanted places, like your beard. When someone inherits two mutated versions of the MC1R-gene (one from each parent), less red pigment is converted into black pigment. ...