Our DNA is locked in a constant battle with itself. It’s fighting to control mobile bits of genetic material that copy themselves and spread through the genome—so-called jumping genes. But that’s a molecular game of Whac-A-Mole: For every bit it manages to suppress, another finds a way to break free. A new study has pinned down genes that have evolved to thwart these molecular intruders. The work paints a picture of the ongoing evolutionary struggle being waged within our genome.“It’s very interesting, this yin and yang of evolutionary changes,” says Haig Kazazian, a geneticist from the University of Pennsylvania who was not involved with the study. “Nobody has looked at these proteins in the light of evolutionary change.” The work could have applications ranging from stem cell development to cancer prevention and may even lead to a deeper understanding of how the cell makes use of its genetic material.Sequences of DNA that can self-replicate and then insert themselves into new locations in the genome are called transposons, or, more simply, jumping genes. They can cause problematic mutations if they jump into important genes: One that inserts itself into a gene used for slowing cell growth could cause cancer, for example. So our genomes have evolved countermeasures. Those countermeasures include a large family of genes that code for proteins known as KRAB zinc fingers. Establishing the link between a specific KRAB zinc finger and its target jumping gene has been a daunting task, though. 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Next, the team added 14 different zinc finger proteins to the mouse cells one by one, to see which ones could stop the jumping genes from jumping. Two KRAB zinc fingers (KZNF91 and KZNF93) worked against two kinds of human transposons. Jumping genes stopped jumping, the team reported online on 28 September in Nature.Once the zinc fingers were paired with their target jumping genes, the team confirmed that indeed the zinc fingers had evolved shortly after the transposon emerged. When the experiment was repeated using a zinc finger from orangutans or macaques, the human transposons were able to escape. The result suggests that somewhere in our ancestry the jumping genes mutated to dodge the zinc fingers, but the zinc fingers also evolved to silence them once again. “We could actually look at when these zinc fingers arose in relation to when these transposons were active and could see this really interesting evolutionary story,” says Sofie Salama, a UC Santa Cruz biologist involved in the study. “It shows this sort of evolution in action.”These zinc finger proteins turn off more than just the jumping genes. They also control other genes nearby and over evolutionary time can be incorporated into the cell’s program for regulating those genes’ activities, Jacobs says. This unintentional benefit may explain why many zinc finger genes persist in our DNA even after their target jumping genes lose the ability to copy themselves.Primates in particular have shown explosive expansion in the KRAB zinc finger gene family; considerable differences exist in this family even between humans and chimpanzees. Our DNA is 98% identical to chimpanzees, but the big differences come from how and when that DNA is used. Jacobs suggests that many of our species’ distinctive features may have arisen because of changes in gene expression caused by zinc finger regulation. “[Zinc fingers] provide this potential regulatory landscape that can be used by the host to do something interesting and change in interesting ways,” Salama adds. By understanding that regulatory landscape, researchers may be better able to understand how, in various diseases, the way genes get used goes awry and find new ways to correct problems.
Stay on target Justice for the Central Park wood duck, who has been overshadowed by the Central Park Mandarin duck!!! pic.twitter.com/zNPM7q8EF6— Jeva Lange (@Jee_vuh) November 2, 2018 The beauty of nature is everywhere, but a pretty mandarin duck is the latest bird to become an internet celebrity overnight.On Oct. 10, Manhattan Bird Alert posted a video of the duck on Twitter, prompting New York City’s bird-watching community to visit Central Park and catch a glimpse of this gorgeous animal. Manhattan Bird Alert indicated that they had no idea how the bird got there and admired its vibrant appearance.The Central Park Pond’s newly-arrived male Mandarin Duck (we still do not know how it got here) unseated the Wood Duck as prettiest duck in the park. Gus Keri brings us close-up video pic.twitter.com/cauqVt4kSK— Manhattan Bird Alert (@BirdCentralPark) October 11, 2018AdChoices广告The video was taken by Gus Keri, a local bird photographer who spotted the duck in the park. It shows the bird leisurely floating in pond water, as if this beautiful creature was in some sort of museum painting. Unlike other average ducks, mandarin male ducks are known for their colorful feathers that come in purple, blue, and red shades. According to the Royal Society for the Protection of Birds (RSPB), mandarin ducks were introduced to the U.K. by China, and today, these birds are appreciated by people worldwide. The Central Park Mandarin Duck has the other ducks shook! pic.twitter.com/ozTWHlP11f— Chadwick (@ohchadwick) November 1, 2018More on Geek.com:Adorable Cat Crashes Fashion Show, Goes ViralDogs Can Sense Malaria By Sniffing Your ClothesWatch: Cockroach Delivers Karate Kick to Avoid Becoming a Zombie A few weeks later, this mandarin duck is still taking over people’s social media feeds. The Twitter community had some hilarious reactions to this bird’s impromptu visit and they’re still trying to locate the duck in Central Park’s waters. Weather forecasts have actually turned into “mandarin duck forecasts,” as Twitter accounts keep updating the duck’s location for admirers everywhere. Where will he go next? You’ll have to “flock” to your Twitter feed to find out.MANDARIN DUCK is at a NEW location today: Turtle Pond, just north of the 79th Street underpass, mid-park, and SW of the Metropolitan Museum of Art. @EdwardGaillard re-found it. pic.twitter.com/8VaW3auDIy— Manhattan Bird Alert (@BirdCentralPark) November 2, 2018Bird alert: The mandarin duck made an appearance today at Turtle Pond in Central Park.@briggl44 here’s a gift for you: it’s the Mandarin Duck that is hanging out in Central Park. New York’s most famous bird of the moment. Move over Pale Male pic.twitter.com/Fn0nGPKNRJ— Wendy Jacobson (@whazittoya) November 2, 2018 Elon Musk’s Cheeky ‘Nuke Mars!’ Post Is Taking Over TwitterA ‘Star Wars: Galaxy’s Edge’-Themed Cookbook Is Coming This Fall