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.
This animation shows how a growing tumor can recruit nearby blood vessels in order to gain a supply of blood.
In mammals, the controlling clock component that generates a 24-hour rhythm is the suprachiasmatic nucleus (SCN), located in a part of the brain called the hypothalamus. The SCN produces a signal that can keep the rest of the body on an approximately 24-hour schedule. This animation illustrates...
A 3D animation showing how proteins in the cell are tagged for disposal and degraded by the proteasome.
Myosin II is one of the molecules involved in furrow formation in dividing cells. This animation shows how the molecule operates, and how furrowstatin blocks the mechanism and halts division of a cell.
The inner cell mass (ICM) cells of blastocyst-stage early human embryos can be removed and cultured. These cells can be grown in the lab indefinitely. Various growth factors cause these cells to develop into a variety of differentiated cells, such as muscle or nerve cells.
Infection begins when the dengue virus uses receptors on an immune cell's surface to gain entry and release its genome.
This animation describes two different ways by which chemicals migrate through membranes: passive diffusion and active transport.
DNA is tightly packed in the nucleus of every cell. DNA wraps around special proteins called histones, which form loops of DNA called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin in turn forms larger loops and coils to form chromosomes.
Watch this animation to see the molecular tricks that an infectious strain of Escherichia coli uses to infect your gut.
A demonstration by Dr. Meyer showing how a balance of molecular elements trigger genetic pathways that determine the sex of a C. elegans worm.
Time-lapse microscopy showing cell division from 1 to 2 to 4 cell stages in C. elegans with fluorescent chromosomes.
Video of the fertilization of the C. elegans oocyte, the fusion of the egg and sperm nuclei, and the egg laying.
Video closeup of the C. elegans sperm that moves like an amoeba.
Video microscopy of a cytotoxic T lymphocyte in action.
Why has it been so hard to develop a vaccine against HIV? How are new medicines revolutionizing AIDS treatment? Can AIDS be cured?
In four presentations, Donald E. Ganem, MD, and B. Brett Finlay, PhD, discuss the latest advances in understanding how pathogens invade the body and how this knowledge is leading to the development of new therapies. They also explain how new infectious diseases are recognized and how epidemics...
Dr. Brett Finlay explains why bacterial diseases continue to be a major health problem worldwide, causing a third of the world's deaths every year.
Dr. Finlay showcases three types of bacteria to illustrate how molecular biology is allowing researchers to probe the molecular workings of bacterial infections.
Venomous carniverous cone snails are a rich source of molecules for scientific research and potential drug development.
Bacteria are capable of communicating and coordinating their activities with a molecular signaling system called quorum sensing.
The quorum sensing system is a target for a new class of drugs that interfere with virulence without killing bacteria.
In this 13-minute Q&A session, Dr. Bonnie Bassler answers questions on quorum sensing and other topics related to bacteria.
How a nerve cell gets its identity, sends axons, and makes connections with other cells.
The cellular and molecular nature of learning and memory, investigated in simpler sea slugs and more-complex mice.