We all have one: a junk drawer that we stuff full of all our random \u2014 and often useless \u2014 items that we can\u2019t throw away. However, once in a while, there\u2019s something in that drawer that ends up being more useful than we initially thought. According to a new study, this is also true for the human body.<\/p>\n
Scientists have discovered that ancient \u201cjunk\u201d DNA<\/a>, believed to have freeloaded in our bodies since before we stood on two legs, has actually been working overtime. The new research, published in Science Advances<\/a>, claims that this previously dismissed genetic junk plays a crucial role in regulating gene expression.\u00a0<\/p>\n \u201cOur genome was sequenced long ago, but the function of many of its parts remain unknown,\u201d said Fumitaka Inoue, associate professor at Kyoto University, in a press release<\/a>. \u201cTransposable elements are thought to play important roles in genome evolution, and their significance is expected to become clearer as research continues.\u201d<\/p>\n Justice For Junk DNA<\/p>\n In this study, researchers were interested in a particular family of DNA<\/a> sequences called MER11. This family of sequences is made up of what\u2019s known as transposable elements (TEs), repetitive DNA sequences that originated from ancient viruses. After millions of years of primate evolution, TEs now make up almost half of the human genome thanks to their copy-and-paste-like mechanism.<\/p>\n Although they are prominent throughout the body, TEs haven\u2019t been a major focus of any genetic research for two main reasons. Firstly, the high rate of replication and similarity between copies makes these sequences difficult to study. Secondly, TEs have always been looked at as useless, with no important scientific function even worth investigating.\u00a0<\/p>\n Thanks to this new study, TEs are now being recognized for all of the hidden genetic work they\u2019ve been doing. Most notably, the MER11 family of DNA sequences greatly impacts gene expression during early human development.<\/p>\n Read More: More Like a Movie Than a Portrait \u2014 A New DNA Model Redefines Family History<\/a><\/p>\n What Is Gene Expression?<\/p>\n Gene expression is a process that turns information into action. One popular way to think about the process of gene expression is like a switch that controls when, where, and how much a molecule or protein gets expressed. These on\/off switches control a wide range of genetic functions, from what color your hair is to whether or not your body can properly produce insulin.\u00a0<\/p>\n MER11 has now been identified as one of these crucial genetic switches, rewriting the belief that TEs play no important role in our bodies.<\/p>\n Uncovering the Role of Ancient Junk DNA<\/p>\n Scientists were able to make this surprising discovery using a technique that tests thousands of DNA sequences at a time and measures their influence on gene activity. The research team analyzed over 7,000 MER11 sequences, and these analyses showed that a particular subfamily of MER11 had a significant effect on gene expression<\/a>, especially related to developmental signals and environmental cues.<\/p>\n Interestingly, MER11 sequences across primates evolved in different ways, with the sequences from humans, chimpanzees, and macaques each being distinct from one another. In future research, the team hopes to continue exploring these evolutionary differences in MER11 between primates to learn more about ancient viral DNA\u2019s complex biological role.<\/p>\n This study is a great reminder that one primate\u2019s junk can be another primate\u2019s (genetic) treasure!<\/p>\n Read More: Genes Impact On Psychology and How They Influence Your Behavior<\/a><\/p>\n Article Sources<\/p>\n