Dr. Zoghbi shows how a mouse that has been given the gene responsible for Rett syndrome exhibits some of the same neurological symptoms as human Rett patients.
This animation shows how the random deactivation of one of the X chromosomes in a pair can lead to a mozaicism in the expression genes.
The zebrafish heart is similar to the human heart in many respects. But unlike the human heart, the fish heart closes wounds rapidly and then regenerates to nearly full function. Fibroblast growth factor (FGF) is an important molecule in the regeneration process.
This "morph" animation demonstrates how the expression of a particular toolkit gene in a butterfly larva corresponds to the location of the wing eyespots in an adult butterfly.
Delivering a single virus to a cell allows the virus to infect the cell, replicate, and give rise to many progeny viruses. These viruses can then infect many neighboring cells.
The geometric structures of viruses are beautiful and can be used, along with genomic information, to identify them.
This animation shows how a growing tumor can recruit nearby blood vessels in order to gain a supply of blood.
This animation illustrates how a small molecule binds to a protein. As a result of the binding, the protein alters its shape and becomes inactivated.
This animation demonstrates how cancerous cells could be destroyed using a modified virus.
A visual representation of the U.S. AIDS epidemic from 1981 to 1997. Each dot represents 30 cases.
A quarry site in Nevada carries the evolutionary history of a population of stickleback fish that resided there when it was a freshwater lake.
This animation illustrates how mistakes made during DNA replication are repaired.
Prialt does not block the mammalian motor synapse, but blocks the pain pathway in the spinal cord.
PCR is a standard laboratory technique that allows amplification of specific segments of DNA based on complementarity.
Urodele amphibians—newts and salamanders—are able to regenerate fully functional limbs in response to amputation. Cells in and near the limb stump dedifferentiate to form a mass of stemlike cells that can produce all the specialized tissues of the limb, such as muscle, nerves, and blood vessels...
Multiple cone snail toxins attack different molecules of the nervous system and cause paralysis.
Electrical and chemical signals are used by neurons to communicate with one another at contact points called synapses.
How a cell infected by a virus signals cytotoxic T lymphocytes to kill the cell before the virus replicates and spreads.
DNA's chemical properties can be harnessed for a variety of biotechnology applications.
Dengue virus has sophisticated mechanisms for entering a cell, for replicating its RNA genome, and for translating proteins.
In 1950, Erwin Chargaff published a paper stating that in the DNA of any given species, the ratio of adenine to thymine is equal, as is the ratio of cytosine to guanine. This became known as Chargaff's ratio, and it was an important clue for solving the structure of DNA.
Using information from molecular research, this 3-D animation shows how DNA is replicated at the molecular level. It involves an enzyme that unwinds the DNA, and other enzymes that copy the two resulting strands.
The ribosome is a molecular factory that translates the genetic information in RNA into a string of amino acids that becomes a protein. Inside the ribosome, the genetic code of the RNA is read three letters at a time and compared with the corresponding code on a transfer molecule. When a match...
During the process of trying to elucidate the structure of DNA, Jim Watson made some cardboard models to try to understand how DNA nucleotides are paired. It helped him visualize how hydrogen atoms of paired nucleotides interact with each other to form a symmetrical structure that fits the...
The small molecule 'furrowstatin' exemplifies the power of using small molecules to investigate life's processes. When applied to dividing cells, the furrowstatin halts cell division.
How HIV infects a cell and replicates itself using reverse transcriptase and the host's cellular machinery.
When a malaria-carrying mosquito bites a human host, the malaria parasite enters the bloodstream, multiplies in the liver cells, and is then released back into the bloodstream, where it infects and destroys red blood cells.
A mosquito becomes infected with malaria when it sucks the blood from an infected human. Once inside the mosquito, the parasites reproduce in the gut and accumulate in the salivary glands, ready to infect another human host with the next bite.
Adam Barrett describes his seven-drug antiretroviral regimen and the importance of adherence.
Aplysia californica is a marine snail with a simple nervous system suitable for research on learning and memory.
A touch to the Aplysia's siphon causes a gill withdrawal, a simple reflex for studying memory.
An interview with Dr. Zoghbi.
A live recording of muscle activity from Dr. Jessell's biceps and triceps muscles.
An interview with Kwame Atsina, an undergraduate who discusses what it's like to be in a lab doing scientific research.
Dr. Brett Finlay shows how bacteria can grow rapidly to incredible numbers, and also explains what limits this explosive growth.
A demonstration by Dr. Meyer showing how a balance of molecular elements trigger genetic pathways that determine the sex of a C. elegans worm.
Air is an invisible gas as are hydrogen and helium. How can you tell if a balloon contains hydrogen? Hydrogen has particular physical and chemical properties that can be tested. Dr. Cech enlists student volunteers to show how a chemical reaction can be used to identify a substance.
An interview with Grant Barish, a scientist in Dr. Evans's lab.
Adam Barrett, a nurse who is HIV positive, discusses his first symptoms and the challenges of adhering to a drug regimen.
The fight against dengue fever, and the mosquitoes that carry the virus, is being carried out by "brigadistas" in Managua's neighborhoods. Spanish with English subtitles.
An interview with Dr. Bassler.
Charles Runckel, a graduate student in the DeRisi lab, uses the Virochip to examine the mystery of bee colony collapse disorder.
Zinhle Thabethe describes how antiretroviral therapy has changed her life.
Are you a night owl or a morning lark? Noted researcher Dr. Seymour Benzer discusses how the difference between he and his wife sparked his interest in the topic of biological clocks.
The bobtail squid swims during the night to hunt. During the day, it burrows to hide from predators.
A demonstration by Dr. Barbara Meyer of how a branched genetic pathway can be affected by mutations in different parts of the pathway.
Corn was originally bred from the teosinte plant by native Mexican farmers. The morphologies of modern-day corn and teosinte plants are compared to illustrate how artificial selection can bring about dramatic changes in plants.
An interview with Silvia Caballero, an undergraduate who discusses what it's like to be in a lab doing scientific research.
Mr. Carlson outlines the path that he took to becoming a graduate student in the White lab, including his experience as a chef.
An interview with Dr. Carroll.