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More than 400 scientists, bioethicists, and historians from 20 countries on 6 continents have gathered this week in Washington, DC, for the Human Gene Editing Summit. The attendees are a veritable who's who of genome editing: Jennifer Doudna of the University of California, Berkeley, Emmanuelle Charpentier of Max Planck Institute for Infection Biology, and Feng Zhang of the Broad Institute of MIT and Harvard-the three discoverers of the CRISPR-Cas9 system's utility in gene editing-plus dozens of other big names in genome science. Cal Tech's David Baltimore along with the heads of the four national societies hosting the meeting (US National Academy of Sciences, US National Academy of Medicine, Chinese Academy of Sciences, and the U.K.'s Royal Society) provided opening remarks on Tuesday (December 1). And as I sat stage right in the NAS auditorium, I noticed the unmistakable rear profile of Harvard Medical School's George Church three rows in front of me. Church was scheduled to speak at a session later that afternoon about the application of CRISPR and other new precision gene editing techniques to the human germline-a hot-button topic since April, when a Chinese group published it had successfully modified the genomes of human embryos, and the National Institutes of Health (NIH) said it would not fund such research. Then in September, the U.S./U.K.-based Hinxton Group, an international consortium of scientists, policy experts, and bioethicists, said it supported the use of genetic editing in human embryos for limited applications in research and medicine.  

The origin of viruses remains mysterious because of their diverse and patchy molecular and functional makeup. Although numerous hypotheses have attempted to explain viral origins, none is backed by substantive data. We take full advantage of the wealth of available protein structural and functional data to explore the evolution of the proteomic makeup of thousands of cells and viruses. Despite the extremely reduced nature of viral proteomes, we established an ancient origin of the "viral supergroup" and the existence of widespread episodes of horizontal transfer of genetic information. Viruses harboring different replicon types and infecting distantly related hosts shared many metabolic and informational protein structural domains of ancient origin that were also widespread in cellular proteomes. Phylogenomic analysis uncovered a universal tree of life and revealed that modern viruses reduced from multiple ancient cells that harbored segmented RNA genomes and coexisted with the ancestors of modern cells. The model for the origin and evolution of viruses and cells is backed by strong genomic and structural evidence and can be reconciled with existing models of viral evolution if one considers viruses to have originated from ancient cells and not from modern counterparts.

This 5 lesson unit, which was designed by teachers in conjunction with scientists, ethicists, and curriculum developers, explores the scientific and ethical issues involved in stem cell research. The unit begins with an exploration of planaria as a model organism for stem cell research. Next, students identify stages in the development of human embryos and compare the types and potency of stem cells. Students learn about a variety of techniques used for obtaining stem cells and the scientific and ethical implications of those techniques. While exploring the ethics of stem cell research, students will develop an awareness of the many shades of gray that exist among positions of stakeholders in the debate. Students will be provided an opportunity to become familiar with policies and regulations for stem cell research that are currently in place in the United States, the issues regarding private and public funding, and the implications for treatment of disease and advancement of scientific knowledge. The unit culminates with students developing a position on embryonic stem cell research through the use of a Decision-Making Framework. Two culminating assessments are offered: In the individual assessment, students write a letter to the President or the President's Bioethics Committee describing their position and recommendations; In the group assessment, students develop a proposal for NIH funding to research treatment for a chosen disease using either embryonic or 'adult' stem cells.

7:00 video: This film is the first of a two part series on the evolution of new genetic information. Here we focus on Point Mutations - the simplest natural mechanisms known to increase the genetic information of a population. Our second film of the series will focus on duplication events - natural mutations that increase the total amount of genetic information of an individual. This film was produced under the guidance of molecular biologist Dr. Nicholas Casewell. http://www.lstmed.ac.uk/about/people/... Point mutations are small, natural edits in the DNA code of an individual. These edits can be passed from parent to child. Because they are mere edits, point mutations usually do not increase the total amount of information in an individual. As new information is gained, old information is lost. Point mutations do, however, increase the total amount of information within a population. In this film you will see several examples of beneficial point mutations which have enhanced a creatures abilities or even given rise to entirely new abilities. The first two examples were directly observed in bacteria by scientists in the lab. The third is a case found in domestic dogs, the last example was discovered in several species of wild animal.

"This modular case study tells the story of Dan and Annie, a married couple of Acadian ancestry who have a genetic form of deafblindness called Usher syndrome. They live in Southwest Louisiana, home of the largest population of DeafBlind citizens in the United States. Acadian Usher syndrome is caused by an allele of the USH1C gene that came to Louisiana with the first Acadian settlers from Canada who founded today's Cajun population. This allele's single nucleotide substitution creates an erroneous splice site that produces a defective cytoskeletal protein (harmonin) of the cochlear and vestibular hair cells and retinal photoreceptors. This splice site is the target of a promising gene therapy. The case study applies and connects Mendelian inheritance, chromosomes, cell division, vision and hearing, DNA sequences, gene expression, gene therapy and population genetics to a specific gene and its movement through generations of Dan and Annie's families.  After the introduction, each of the remaining sections can be used independently either for in-class team activities or out-of-class extensions or assignments over an entire year of introductory undergraduate biology. "

n this interrupted case study, students learn about the influence of early fetal nutritional conditions on the expression of genes related to metabolism and growth. Beginning with the true event of a food and fuel embargo that led to famine in the western Netherlands toward the end of World War II, students learn about the historical background of the Dutch Hunger Winter and its social impact. Using real data from the study conducted by Heijmans and coauthors (2008), students then compare the methylation level of a specific gene between individuals conceived during the famine and their unaffected siblings, and how changes in the expression of this metabolically important gene may impact the risk of developing type 2 diabetes. Supported by other studies on mice and in humans, students conclude that in utero events may impact the health of individuals later in life through epigenetic mechanisms. The case is ideally suited for a molecular or cell biology course, but is also appropriate for an introductory biology course in which students have an understanding of descriptive statistics, interpretation of statistical test results, eukaryotic gene structure, and regulation of gene expression.

Quintana-Murci and his colleagues also took advantage of a previously published map of areas of the human genome where Neanderthal genes are present, showing that innate immune genes are generally more likely to have been borrowed from Neanderthals than genes coding other types of proteins. Specifically, they noted that 126 innate immune genes in present-day Europeans, Asians, or both groups were among the top 5 percent of genes in the genome of each population most likely to have originated in Neanderthals. The cluster of toll-like receptor genes, encoding TLR 1, TLR 6, and TLR 10, both showed signs of having been borrowed from Neanderthals and having picked up adaptive mutations at various points in history. Meanwhile, a group led by Janet Kelso of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, used both the same previously published Neanderthal introgression map that Quintana-Murci used and a second introgression map. The researchers searched for borrowed regions of the genome that were especially long and common in present-day humans, eventually zeroing in TLR6, TLR10, and TLR1. These receptors, which detect conserved microbial proteins such as flagellin, are all encoded along the same segment of DNA on chromosome four.

This directed case study was developed to introduce students to the CRISPR-Cas9 system for genome editing. CRISPR-Cas9 has made numerous headlines in both the scientific and popular press, and thus serves as an excellent model for learning current biotechnology and applying concepts from biology courses. After providing a general overview of CRISPR-Cas9, the majority of the case focuses on the clinical applications of the system as experienced by a carrier for the X-linked recessive allele underlying Duchenne Muscular Dystrophy. The case is structured so that students use a variety of popular and scientific sources (some of which may require a subscription to access-check with your institution), increasing in difficulty as they move through each part of the case. The goals are for students to learn the molecular mechanisms of CRISPR-Cas9, the benefits and limitations of the system, and the clinical applications of the technology. Open-ended questions are included to spark discussion of ethical considerations, societal impacts, and the overall implications of the technology.

Many biology courses are designed to develop student understanding and application of the scientific method, but few seriously examine the various ethical questions associated with scientific research. This interdisciplinary case study presents three experiments and asks not only if they are scientifically valid but whether they were ethically performed.  The experiments examine the psychology of love, a cause of breast cancer, and how the immune system functions in the presence of cancer. Based on their opinions of the validity and ethics of each experiment, students are asked to conclude which of the experiments were actually conducted by scientists and which are fictional. Students should already be familiar with the scientific method, but information on the Georgetown Mantra and Nuremberg Code.is included. The case could be modified for use in non-majors and majors classes.  The format of the case challenges students of any background to use information from both science and ethics to see how the differing approaches of scientist and ethicist can complement and strengthen each other.

This case study details the historical discovery of the structure of DNA. Images of this key molecule are as iconic as those of the Mona Lisa, and identifying its structure has proven to be as intriguing a mystery for scientists as the reason behind Mona Lisa's smile has been for art historians. The case is woven together by a series of fictional diary entries that detail the history of the discovery of DNA's structure, the major players involved, their ethical dilemmas, and the role of women in science. The case is designed for a high school course or introductory undergraduate genetics/ biochemistry courses. It can also be used as an interdisciplinary case study bridging genetics, bioethics, art, and the status of women in science. Designed as an interrupted case, it may be used in its entirety or in parts that pertain to a particular topic or discipline. No prior knowledge of genetics is required.

The Miller-Urey experiment was the first attempt to scientifically explore ideas about the origin of life. Stanley Miller simulated conditions thought be common on the ancient Earth. The purpose was to test the idea that the complex molecules of life (in this case, amino acids) could have arisen on our young planet through simple, natural chemical reactions. The experiment was a success in that amino acids, the building blocks of life, were produced during the simulation. The finding was so significant that it kick started an entirely new field of study: Prebiotic Chemistry. Scientists now have reason to believe that the gases used in the Miller-Urey simulation were not actually the same as those of the ancient atmosphere. Because of this, many experiments have since been done, testing a wide variety of atmospheres and different environmental conditions. The results are overwhelming: the molecules of life can form under a wide variety of ancient Earth-like conditions. Many questions about the origin of life remain to be answered but these findings give strong support to the idea that the first living cells on Earth may have emerged from natural chemical reactions.

This case study provides an overview of the seminal experimental work that led to the discovery of DNA structure and the confirmation of the semi-conservative model of DNA replication. By guiding students through a chronological series of historic experiments and discussing some of the collaborations and controversies involved in the original research, students learn about the history and nature of science in addition to several important biological concepts. A number of recommended videos, including one created by the author, enable instructors to use the "flipped-classroom" mode of instruction according to which students read primary literature and watch videos on their own before group discussions and activities. The case study was developed for use in an introductory undergraduate biology course, and would also be appropriate for use in a high school biology course. Some prior knowledge or instruction may be required, depending on the level and learning objectives of the course.

In this case study students are provided with information for piecing together the story of how forest fragmentation and biodiversity loss can affect the risk of Lyme disease transmission to humans. The case introduces the dilution effect, a widely accepted theory-and one of the most important ideas in disease ecology-which suggests that disease risk for humans decreases as the diversity of species in an area increases. It also explains how landscape fragmentation, one of the most common threats to biodiversity, can influence the risk of Lyme disease for humans. Students interpret and discuss various figures to develop a concept map that connects all the individual results of the story. Students gain an appreciation for the complexity of species interactions in an ecosystem, the effects of forest fragmentation on these interactions and the possible consequences for human health. This activity was developed for an undergraduate introduction to environmental sciences course under the topic of biodiversity and conservation, but would also be suitable for interdisciplinary studies interested in examining the connections between conservation and public health.

This case study explores the recent (2010 - 2016) outbreak of neural tube defects, specifically anencephaly, in a rural three-county region of Washington state, particularly Yakima, WA. The case study focuses on the biological aspects of teratogens that may cause birth defects as well as epidemiological investigations of disease outbreaks. By the end of the case, students will have explored how our environment may have severe biological consequences on the human body during pregnancy and will have evaluated governmental and scientific investigations of a rare outbreak of birth defects. This clicker case study was developed for a non-majors biology course entitled "Human Development: Conception to Birth," although it could be taught in any introductory biology course for majors or non-majors during a unit on human reproductive biology or developmental biology. The case assumes that students have no prior knowledge of developmental biology or birth defects. The case study could also be adapted for upper-division courses by getting more in-depth on the specifics of teratogen mechanisms, the developmental biology and physiology of neural tube defects, or more complex epidemiological analyses.

How are the stages of mitosis related to the creation of identical daughter cells? The primary function of the stages of mitosis is to make certain that each daughter cell is genetically identical to the mother cell. The mother cell's DNA is copied during interphase. During mitosis the chromosomes condense from long strands to highly coiled structures. The two copies of each DNA strand, called sister chromatids, are physically attached to one another. The chromosomes are moved to the center of the cell and split apart in a highly coordinated fashion. The condensation of the chromosomes, the physical connection of the sister chromatids, and the precise movement of the chromosomes are all important in making sure that each daughter cell has one copy of each chromosome and is genetically identical to the mother cell.

Biologists estimate that there are about 5 to 100 million species of organisms living on Earth today. Evidence from morphological, biochemical, and gene sequence data suggests that all organisms on Earth are genetically related, and the genealogical relationships of living things can be represented by a vast evolutionary tree, the Tree of Life. The Tree of Life then represents the phylogeny of organisms, i. e., the history of organismal lineages as they change through time. It implies that different species arise from previous forms via descent, and that all organisms, from the smallest microbe to the largest plants and vertebrates, are connected by the passage of genes along the branches of the phylogenetic tree that links all of Life (Figure 1).

The purpose of this case is to teach introductory college biology students the basic process of mitosis, focusing on the fundamental cellular processes that occur during each of the stages-prophase, prometaphase, metaphase, anaphase, telophase and cytokinesis. It would also be appropriate for AP Biology students. The case is framed around solving a murder. The murder plot involves a naturally-occurring poison derived from Yew trees, known as paclitaxel. Paclitaxel is a mitotic inhibitor that works by inhibiting the depolymerization of microtubules so that the cell is arrested in metaphase. At the end of the case, students will be able to describe the basic process of mitosis, including the fundamental processes that occur in each stage. The discovery of paclitaxel led to the development of the chemotherapeutic drug, Taxol ®, and the case concludes by having students think about the correlations between poisons and chemotherapies. The case involves the use of videos, one of which was made by the author for this case, and can be used in a flipped classroom.

This case study teaches students about allopatric speciation through an investigation of the benthic and limnetic sticklebacks of Paxton Lake, which are among the youngest species on Earth, diverging from each other after the Pleistocene glaciers melted and the Gulf Islands formed. Researchers at the University of British Columbia have carried out a variety of fascinating studies on these hardy little fish. Results from this research (formatted as data sheets included in the teaching notes) are provided to students who design experiments and then compare actual data to investigate why benthic and limnetic sticklebacks seldom interbreed in Paxton Lake. Developed for a first-year biology course for majors organized around the general theme of evolution and the history of life on Earth, this case study is an updated version of another case in the collection, "Something's Fishy in Paxton Lake" (Sharp, 2001). The current version is especially suited for a flipped classroom in which students prepare for class ahead of time with a reading assignment that also involves the viewing of a video by the case authors that introduces the mechanisms of allopatric speciation.

The theory of evolution by natural selection is simple, elegant, and profound. Yet, a large number of undergraduate students including biology majors, medical students, and pre-service science teachers maintain a large set of misconceptions that interfere with a solid understanding of the process of natural selection. It is also well known that lecturing is an insufficient strategy to help students confront and correct these misconceptions. This activity uses the evolution of coat color in oldfield mice (Peromyscus polionotus) as the basis of a case study in which students investigate the role of variation, heritability, and selection in the evolution of a trait. Students examine graphs, data, and excerpts from a series of papers that have been published about this system over the last 100 years. The content is delivered as an interrupted case and encourages peer-to-peer teaching and interaction. The case is appropriate for use in non-major, introductory, or advanced biology courses.

This interrupted case study examines basic concepts of chemical bonding by telling the story of "Madison," a young girl eager to learn how her hair can transition from natural curls to straight, smooth tresses. The case can be used to teach or review the major categories of bonds (ionic, covalent and hydrogen), major macromolecules of life, and hydrolytic and dehydration reactions. It also explores how chemical relaxers and heat through blow drying and flat-ironing can change the nature of straight, wavy and curly hair through the disruption of protein shape. Students will thus learn what it means when a protein has become denatured and how various variables such as pH, heat and salts can lead to the unraveling of the three-dimensional shape of proteins. This case is suitable for an AP high school course, or for an introductory biology or chemistry course for majors or non-majors. This activity can also be used as a review of basic biology and chemistry for students in an upper-level biochemistry course.