Every December Science looks back at the past year to determine which scientific achievements, discoveries, or developments were most significant. At the end of the month, they announce the Breakthrough of the Year and nine runners-up of note. In 2015, there were plenty of options to choose from, including the development of a vaccine for the dreaded Ebola virus; the discovery of a new hominin, Homo naledi; the sequencing of Kennewick Man's nuclear genomes; and the exploration of dwarf planets at the far reaches of our solar system, the top choice in a readers' poll of the finalists.
In the end, though, the top prize went to clustered regularly-interspaced short palindromic repeats (CRISPR), a low-cost but efficient strategy for genome engineering that was a Science runner-up in 2012 and 2013 and is the first runner-up ever to be elevated to the top spot in a subsequent year. CRISPR can be used to target and modify DNA with groundbreaking accuracy.
While several gene editing techniques have had success in the last decade, CRISPR's ease of use and affordability allows nearly any molecular biology research lab and even some high schools to make use of it, and the research it has helped advance include disabling retroviruses encoded in the pig genome that have long posed a safety concern for transplanting organs from pigs to humans; developing a gene drive, which allows an introduced gene to be transmitted throughout pest populations faster than naturally possible, offering hope for combatting vector-borne illnesses; and the first deliberate editing of the DNA of human embryos, done by Chinese researchers earlier this year. While this last revolutionary development leads scientists and doctors to hope that potential genetic therapies and treatments will soon be discovered for various diseases, it also raises concerns about and necessitated an international summit on human genetic engineering.
As Science Editor-in-Chief Marcia McNutt notes, "Researchers have long sought better ways to edit the genetic code in cultured cells and laboratory organisms to silence, activate, or change targeted genes to gain a better understanding of their roles. This, in turn, could open the door to beneficial applications, from ecological to agricultural to biomedical." CRISPR may well be the tool that researchers have been waiting for to bring theory to practical usage.
Read more about CRISPR, the editorial announcing its victory, and some of the studies and news in which it has been featured. (It should be noted that while these links point to pages that are publicly accessible, many of the internal links included on them are behind a firewall for Science subscribers.) You also can listen to a podcast of Science editors discussing this year’s breakthrough, breakdowns, and top news stories. Don't have 38 minutes to listen? Science Update offers a minute-long podcast highlighting the breakthrough.
Want to look deeper into one of the studies CRISPR has contributed to with your students? Science in the Classroom's Stop! Codon Time! offers annotations and teaching materials for the journal article, "Stop codon reassignments in the wild," published in Science May 23, 2014.
Science Update also has short podcasts summarizing some of the runners-up, including Kennewick Man’s DNA, Deep Mantle Plumes, Reproducibility in Psychology, Homo Naledi, Dwarf Planets, and The Lymphatic Brain.
Science NetLinks offers a variety of resources on genes and genomes: DNA from the Beginning is an animated website on the basics of DNA, genes, and heredity. The Macaque Genome: An Interactive Poster allows students to learn about the importance of the rhesus macaque and of comparative genomics to studies of human genetics, evolution, and biology. The lesson Cracking the Genetic Code helps students understand what the knowledge of DNA can tell us about ourselves and other organisms and species, as well as to learn about the systematic study of the human genome. In From Cell to DNA, students are introduced to the genetic information stored in DNA within the human cell nucleus. while in the Extracting DNA lesson, students develop understanding of DNA by modeling the process of DNA extraction. We also have podcast resources on proteomes, genes and geography, sleep and gene expression, and color-coded DNA.