Repurposing of a DNA segregation machinery into a cytoskeletal system controlling cell shape - Science | AAAS

Cephalopods, like the octopus, have specialized arms and suckers, but how these structures evolved from the simple bodies of their mollusk ancestors remains a mystery. Researchers from the University of Tokyo compared gene activity during embryonic development of cuttlefish, octopus and snail body parts. They found that several genes associated with appendage patterning showed expression along developing cephalopod arms, but no comparable patterns in developing suckers. Developing suckers instead expressed Ets1, a gene associated with early embryonic development in mollusks. The findings suggest cephalopods evolved suckers by reusing existing genes in new ways.

The head of fan group Football Supporters Europe says a lack of segregation at the World Cup is "a risk", and shows Fifa has "lost control of their ticketing". Most group games so far have been played in front of fans of both countries mingling at venues - in stark contrast to what is normally the case in football. Ronan Evain, executive director of Football Supporters Europe, told BBC Sport: "The absence of segregation is not normal for a tournament like this. "What is worrying is that Fifa doesn't really know who has tickets here and there... by pushing so much for people to buy tickets and re-sell them. "So the possibility - or the risk - to have fans from 'Team A' in the middle of the crowd of 'Team B' is stronger than ever before. "Evain was speaking in Dallas, where BBC Sport saw pockets of Dutch and Japanese fans mixed together when the two teams played each other on Sunday. "I don't know if there are mitigation measures in place, but the risk does exist," he said. "Hopefully this kind of situation can be solved by just switching tickets and people moving from one section to another.

Young chimpanzees enjoy some fruit. (Martin Harvey/The Image Bank RF/Getty Images) Humans and chimpanzees are remarkably similar, despite the major differences in how our societies have panned out. After about 5-6 million years of evolution from a common ancestor, only 1.2 percent of our DNA is different. A virus that infected chimpanzees (Pan troglodytes) – but not humans – about 4 million years ago is partly responsible. This ancient retrovirus made a tiny tweak to chimp DNA that has led to some major differences in how our brains develop, according to a new study published in Science Advances today. "We wanted to understand how human and chimpanzee brains could have evolved differently when so many of their protein-making genes are similar," lead author Patricia Gerdes told ScienceAlert. Gerdes is a molecular neurogeneticist at Lund University in Sweden. "We knew that ancient viruses can leave DNA behind in the genome, and those remnants can affect nearby genes," she said. "PTERV1 (Pan troglodytes endogenous retrovirus-1) was a particularly interesting candidate because it is found in chimpanzees and other African apes but not in humans.