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Readings of milestone biological discoveries and the scientist behind them

Researchers have now created the first molecules of RNA, DNA's singled-stranded relative, that are capable of copying almost any other RNAs. The discovery bolsters the widely held view among researchers who study the origin of life that RNA likely preceded DNA as the central genetic storehouse of information in the earliest cells some 4 billion years ago.

This case study follows a young cystic fibrosis (CF) patient named Lucas. Through Lucas's story and interactions between his parents and pediatrician, students learn about the scientific background and basis of CF. By reviewing email correspondence between Lucas's parents and various doctors, students gain an overview of CF research. CF has become a model disease in certain undergraduate biology classrooms due to its relatively clear mechanism and genetic basis. This case asks students to come up with their own ideas to improve on an existing line of research - gene therapy - in treating CF. During the process, students will gain a better appreciation of the innovative nature of science and develop research skills such as finding, understanding and analyzing primary literature. The activity was originally designed for first- and second-year students as part of an extracurricular case competition, but may be used for any undergraduate biology level. The case assumes basic (high school level) knowledge of genetics, biochemistry, cell biology and physiology.

Fact sheet: Metastatic cancer is cancer that has spread from the place where it first started to another place in the body. A tumor formed by metastatic cancer cells is called a metastatic tumor or a metastasis.

The study is the first to find that people's bodies metabolize bisphenol-A (BPA) - a chemical found in most people and used in polycarbonate plastic, food cans and paper receipts - into something that impacts our cells and may make us fat. The research, from Health Canada, challenges an untested assumption that our liver metabolizes BPA into a form that doesn't impact our health.

So how do animals play a role in this research? Well, in a couple of ways. First, the chlorotoxin in Tumor Paint was derived from scorpion venom. Second, researchers worked with dogs before moving into human trials to determine the likelihood of success. After promising results in canines, human trials are now underway at Cedars Sinai Medical Center! Right now, the study is aimed at proving that Tumor Paint is able to reach the brain tumor successfully. If all goes well, it's possible that this could lead to more successful surgical outcomes.

Research has revealed striking differences in the trillions of bacteria - a.k.a., the microbiome - in the intestines of children with and without autism. But the gut bacteria in individuals with autism aren't just different. Researchers at the California Institute of Technology have shown for the first time that they may actually contribute to the disorder. They reported in the journal Cell in December 2013 that an experimental probiotic therapy alleviated autism-like behaviors in mice and are already planning a clinical trial.

By early 2014, Flint, Kendler and a team of collaborators had analysed DNA sequences from 5,303 Chinese women with depression, and another 5,337 controls. As Flint expected, 85% of the depressed women had a severe form of the disorder called melancholia, which robs people of the ability to feel joy. "You can be a doting grandparent and your favourite grandchildren can show up at your door," says Douglas Levinson, a psychiatrist at Stanford University in California, "and you can't feel anything." The analysis yielded two genetic sequences that seemed to be linked to depression: one in a stretch of DNA that codes for an enzyme whose function is not fully understood, and the other next to the gene SIRT1, which is important for energy-producing cell structures called mitochondria. The correlations were confirmed in another set of more than 3,000 depressed men and women and over 3,000 controls.

This case study synthesizes students' knowledge of the central dogma and cell structure by examining a rare health disorder in order to understand protein targeting and its medical consequences. Students first identify the molecular alteration in affected members of a family with renal Fanconi syndrome as reported in the New England Journal of Medicine (2014). Students then use an online bioinformatics tool to analyze the wildtype and mutant proteins and examine their subcellular localization. Finally, students use this information to explain the symptoms of affected family members. The case is delivered with a PowerPoint presentation that includes a selection of brainstorming prompts and "clicker questions." Students complete a worksheet (included in the teaching notes) before class, making the activity suitable for a flipped classroom. A second worksheet (also included in the teaching notes) is completed during class. The case is written for an introductory biology course for majors, but could also be used as a unit capstone in a non-majors human biology course; the case is also scalable to upper division courses in physiology that specifically explore kidney function.

This clicker case was designed to teach students about basic enzyme structure, mechanisms of enzyme inhibition, and mechanisms of drug resistance. The story follows Oliver Casey, a patient afflicted with Chronic Myelogenous Leukemia (CML). CML is caused by a chromosomal mutation that affects the tyrosine kinase ABL, an enzyme important in regulating cell growth and proliferation. The chromosomal mutation gives rise to the BCR-ABL fusion gene that produces a constitutively active ABL kinase, which causes the leukemia. In May 2001, the Food and Drug Administration approved the use of a rationally designed tyrosine kinase inhibitor, imatinib (Gleevec®), for the treatment of CML. During that same month, Gleevec made the cover of TIME magazine, described as "new ammunition in the war on cancer." The case is structured for a flipped classroom environment in which students view preparatory videos (including one by the author) on their own before beginning the case. Written for a first-year introductory biology course, the case could also be adapted for AP/Honors high school biology or a cancer biology course.

The life science/biology course is divided into 12 instructional segments grouped into four sections. In the first section, From Molecules to Organisms: Structures and Processes, students develop models of how molecules combine to build cells and organisms (IS1 [Structure and Function]; IS2 [Growth and Development of Organisms]; IS3 [Organization for Matter and Energy Flow in Organisms]). In the second section, Ecosystems: Interactions, Energy, and Dynamics, students zoom out to the macroscopic scale to show how organisms interact (IS4 [Interdependent Relationships in Ecosystems]; IS5 [Cycles of Matter and Energy Transfer in Ecosystems]; IS6 [Ecosystem Dynamics, Functioning, and Resilience]; IS7 [Social Interactions and Group Behavior]). Students return to the role that DNA plays in inheritance during the third section, Heredity: Inheritance and Variation of Traits (IS8 [Inheritance of Traits]; IS9 [Variation of Traits]). The class ends tying together interactions at all these scales by explaining evolution and natural selection in Biological Evolution: Unity and Diversity (IS10 [Evidence of Common Ancestry and Diversity]; IS11 [Natural Selection]; IS12 [Adaptation and Biodiversity]). A vignette in IS12 illustrates the level of three-dimensional understanding students are expected to exhibit as a capstone of the course.

An international team led by Professor Itai YanaAi of the Technion-Israel Institute of Technology Department of Biology made the discovery after using an extraordinarily powerful technique known as CEL-Seq. CEL-Seq monitors individual cells for their gene activity (as detected via mRNA)-and they applied it across 10 different species, with CEL-Seq being applied to 70 embryos per species. In particular, they were interested in whether the animal classification of phylum-which separates animals into groups according to their body plans-is actually a useful tool for placing animals into groups, as well as what genetic attributes are the same and different between the different phyla.

There's a lot we don't know about how and when dogs were first domesticated. But we do know that the process made dogs very different from their wild cousins, in some unexpected ways.