background preloader

DNA from the Beginning -animated experiments

DNA from the Beginning -animated experiments
DNA from the Beginning is organized around key concepts. The science behind each concept is explained by: animation, image gallery, video interviews, problem, biographies, and links. DNAftb blog: It's the season of hibernation, something I've always wished I could do. Feature: We have relaunched the Weed to Wonder site as a flexible "e-book" that can be viewed as a website, an app, or a printable PDF. Mailing List Gene News - Scientists create living organ in mice in world-first breakthrough Find the DNALC on: Language options: Related:  Genetics

Did natural selection make the Dutch the tallest people on the planet? AMSTERDAM—Insecure about your height? You may want to avoid this tiny country by the North Sea, whose population has gained an impressive 20 centimeters in the past 150 years and is now officially the tallest on the planet. Scientists chalk up most of that increase to rising wealth, a rich diet, and good health care, but a new study suggests something else is going on as well: The Dutch growth spurt may be an example of human evolution in action. The study, published online today in the Proceedings of the Royal Society B, shows that tall Dutch men on average have more children than their shorter counterparts, and that more of their children survive. "This study drives home the message that the human population is still subject to natural selection," says Stephen Stearns, an evolutionary biologist at Yale University who wasn't involved in the study. For many years, the U.S. population was the tallest in the world. Just how these peoples became so tall isn't clear, however.

Might Alien Life Evolve Like the Incredible Octopus? by Natalie Shoemaker Consider the octopus: a creepy skeleton-less creature with limbs that have regenerative properties and a mind of their own. Its structure — inside and out — makes it like no other animal on earth. As a part of the Mollusca phylum, the octopus seems so far removed from its clam cousin. Neurobiologist Benny Hochner, from the Hebrew University of Jerusalem in Israel, talked about this oddity in an interview with Alison Abbott from Nature: “Very simple molluscs like the clam — they just sit in the mud, filtering food. Scientists have marveled at the octopus for years, and now they've taken the time to delve deeper into its biology by decoding its genome. "The octopus appears so utterly different from all other animals, even ones it's related to, that the British zoologist Martin Wells famously called it an alien. “It’s important for us to know the genome, because it gives us insights into how the sophisticated cognitive skills of octopuses evolved.”

DNA Deoxyribonucleic acid (DNA) is a long chain organic molecule that contains the coding for all metabolic and reproductive processes of all living organisms, save for certain viruses. This helix shaped molecule consists of a spine that contains a sequence of nucleotides, whose order comprise the coding instruction for each specific lifeform. DNA itself is not alive, but holds the instruction set for building a vast array of proteins as well as its own replication. By governing the synthesis of proteins, DNA is inherently the key substance for the maintenance and replication of every cell in nature, as well as DNA-containing viruses that subsist in another organism's host cells. A single DNA molecule contains all the information required to assemble any complete organism; in fact, the macro-structure of circular versus linear DNA geometry distinguishes biological domains (e.g. prokaryote versus eukaryote). Double helix DNA model The double helix Sense and anti-sense strands Supercoiling

DNA study shows Celts are not a unique genetic group 18 March 2015Last updated at 14:00 ET By Pallab Ghosh Science correspondent, BBC News "What's fascinated historians is why over such a short space of land, the people are so different", as Pallab Ghosh reports A DNA study of Britons has shown that genetically there is not a unique Celtic group of people in the UK. According to the data, those of Celtic ancestry in Scotland and Cornwall are more similar to the English than they are to other Celtic groups. The study also describes distinct genetic differences across the UK, which reflect regional identities. And it shows that the invading Anglo Saxons did not wipe out the Britons of 1,500 years ago, but mixed with them. Published in the Journal Nature, the findings emerge from a detailed DNA analysis of 2,000 mostly middle-aged Caucasian people living across the UK. Continue reading the main story “Start Quote End QuoteProf Mark RobinsonOxford University Striking similarities Who do you think you are? Continue reading the main story

Making of Europe unlocked by DNA DNA sequenced from nearly 40 ancient skeletons has shed light on the complex prehistoric events that shaped modern European populations. A study of remains from Central Europe suggests the foundations of the modern gene pool were laid down between 4,000 and 2,000 BC - in Neolithic times. These changes were likely brought about by the rapid growth and movement of some populations. The work by an international team is published in Nature Communications. Decades of study of the DNA patterns of modern Europeans suggests two major events in prehistory significantly affected the continent's genetic landscape: its initial peopling by hunter-gatherers in Palaeolithic times (35,000 years ago) and a wave of migration by Near Eastern farmers some 6,000 years ago. Family tree The latest paper reveals that events some time after the initial migration of farmers into Europe did indeed have a major impact on the modern gene pool. Haplogroup H dominates mtDNA variation in Europe. Migrant wave

Gene drives spread their wings Genies are said to have the power to grant three wishes. But genies recently released from laboratory flasks promise to fulfill nearly any wish a biologist can dream up. End the scourge of insect-borne diseases? Check. These genies aren’t magical; they are research tools known as gene drives — clever bits of engineered DNA designed to propel themselves into the DNA of a pesky or troubled organism. Gene drive enthusiasts say these genies could wipe out malaria, saving more than half a million lives each year. Scientists have sought the power of gene drives for decades. “Everything is possible with CRISPR,” says geneticist Hugo Bellen. But genes designed to spread through populations and alter ecosystems could have unforeseen consequences. As yet, no CRISPR gene drive has been released in the wild — few have even been built. Story continues after graphic Rule breakers Gene drives aren’t naked DNA floating around the air and water. Story continues after table Engines of change Fast forward

Researchers Observe Grafted Plants Sharing Genomic Information Epigenetic Communication The grafting of one plant onto another is as old as the discovery of agriculture itself (or nearly so); but what has remained mysterious was how the resultant mélange of plant species functioned as a conjoined organism. Scientists at the Salk Institute and Cambridge University have taken a big step toward understanding how it all works, with important implications for agricultural science, and possibly opening up new avenues for the creation of novel forms of genetically-modified (GM) organisms and crop species. The new research, which was published in the Proceedings of the National Academy of Sciences for the week of January 18, 2016, shows that grafted organisms communicate and interact on a genomic level—though not through the transference of actual DNA. Rather, they communicate epigenetically. “Our study showed genetic information is actually flowing from one plant to the other. New Frontiers for Agriculture

Scientists Identify Gene Behind Evolution in Action in Darwin's Finches Scientists from Princeton University and Sweden have discovered a gene that caused a change in a finch within a year’s time span. This was due to a drought that decimated the food supply. This genetic matrix for evolution and natural selection could come in handy in the future. Evolution is a pretty complex process and human beings have hardly come to know the ABCs of this intricate intelligence that governs Nature (both the original one and the human one which is a replica of the former). Environmental transformation coupled with the gene HMGA2 caused the evolution of beak size in a finch known as Geospiza fortis. The 18 bird species that inhabit the island had tiny or huge beaks depending upon several factors. The study was reported in the journal Science. The medium ground finches had perished in their competition with the larger ground finches. The event provoked the comments of the experts. While such has been demonstrated before in bacteria, it has seldom been seen in a vertebrate.

Physicists Find More Evidence That DNA’s Hidden Layer is Real Maybe you’ve wondered, as I have, how it could possibly be that all of the different types of cells in our bodies are made up of the same DNA chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). These chemicals pair of into A/T and C/G base pairs which then form into sequences, or “genes.” So how could the finite number of possible sequences create such a wide range of things, from eyeballs to teeth, hair to heart muscle? Georges Gobet Every cell contains a sequence of some six billion base pairs that are just under 79 inches long(!), or two meters, in length. The obvious question is what determines how a sequence is folded. Robyn Beck Now physicists at Leiden University in the Netherlands have confirmed the presence of this second layer of instructions via computer simulations of baker’s yeast and fission yeast sequences, with various mechanical cues added randomly as a second level of information. Headline image: Mario Tama

Multiplexing Genetic and Nucleosome Positioning Codes: A Computational Approach Abstract Eukaryotic DNA is strongly bent inside fundamental packaging units: the nucleosomes. It is known that their positions are strongly influenced by the mechanical properties of the underlying DNA sequence. Citation: Eslami-Mossallam B, Schram RD, Tompitak M, van Noort J, Schiessel H (2016) Multiplexing Genetic and Nucleosome Positioning Codes: A Computational Approach. Editor: Tamir Tuller, Tel Aviv University, ISRAEL Received: December 22, 2015; Accepted: May 20, 2016; Published: June 7, 2016 Copyright: © 2016 Eslami-Mossallam et al. Data Availability: All relevant data are within the paper and its Supporting Information files. Competing interests: The authors have declared that no competing interests exist. Introduction DNA molecules are much longer than the cells that contain them. In the present study we ask the question whether mechanical information could be written into DNA molecules. Methods and Models Nucleosome model Fig 1.