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.
Video closeup of the C. elegans sperm that moves like an amoeba.
Why has it been so hard to develop a vaccine against HIV? How are new medicines revolutionizing AIDS treatment? Can AIDS be cured?
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.
What medical secrets do venomous snails hold? How can listening in on bacterial conversations help develop new antibiotics? In four presentations, Dr. Bonnie L. Bassler and Dr. Baldomero M. Olivera reveal how a deeper understanding of nature and biodiversity informs their research into new...
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.
As part of the 2003 Holiday Lectures on Science, Dr. Bert Vogelstein and Dr. Huda Y. Zoghbi discuss how their patients have led to a deeper understanding of the genetic and molecular bases of neurological disorders and cancer. Thanks to these patients, researchers can now apply the knowledge...
Although there are numerous kinds of cancer, all stem from alterations that allow cell division to outstrip cell demise.
The identification of hundreds of genes involved in the formation and spread of cancer is leading to promising new methods for diagnosis, prevention, and treatment.
Mutations in key genes can lay waste to the nervous system. By studying large families predisposed to developing these genetic disorders, scientists can identify the responsible altered gene.
Girls with Rett syndrome develop normally for about 18 months and then begin to regress. With the help of affected girls and their families, Dr. Zoghbi and her collaborators searched for the gene responsible for this neurological disorder.
In four talks, A. James Hudspeth, MD, PhD, and Jeremy H. Nathans, MD, PhD, discuss how sensory information is encoded and transmitted to the brain. They describe the detailed workings of two senses of great importance to humans—vision and hearing.
Dr. Hudspeth will begin by discussing how simple organisms—such as bacteria—have the capacity to detect and react to a stimulus.
Dr. Nathans will discuss how the visual process involves the detection of light by photo-receptors in the retina.
Dr. Hudspeth will explain the basis for the ear’s remarkable ability to detect sound through the hair cell, the sensory receptor found in the inner ear.
Dr. Nathans will complete the lecture series by clarifying what is known about the brain’s ability to process and integrate various elements of the visual system, such as color, motion, and depth.
An overview of embryonic development, the progressive differentiation of cells, and properties of embryonic stem cells.
The role of stem cells in regeneration, and ongoing research to improve mammalian regeneration potency.
In cloning, a cell's genetic machinery is reprogrammed. Can we similarly coax stem cells to become specific cell types?