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.
Quorum sensing regulates gene expression by a protein phosphorylation cascade that controls transcription.
The PPAR-delta receptor activates certain genes in a muscle cell, resulting in the burning of fat.
In the stickleback fish, pelvic-fin reduction resulted from changes in the regulatory switch elements of the Pitx1 gene. In the marine ancestor, the Pitx1 gene is activated in the pelvic-fin region during development to generate the fin. In the pelvic-reduced stickleback, the...
This animation shows how the protein MECP2, in conjuction with another protein complex, can act as an "on-off' switch for gene expression.
This animation shows the molecular interactions involved in the negative feedback loop responsible for circadian rhythms in mammals.
General transcription factors, activators, and repressors interact to regulate the transcription of eukaryotic DNA into RNA.
Watch these animations display the dynamic orchestration of the molecular events of the Drosophila biological clock.
Where and when did humans arise? What distinguishes us from other species? Did our distant ancestors look and behave like us?
Genetic evidence shows that humans evolved in Africa and continue to evolve.
How has the amazing diversity of plants and animals evolved? What can fossils, butterflies, and stickleback fish tell us about the deep common ancestry of all living forms?
The genetic mechanisms by which evolution occurs, and an overview of the evidence for evolutionary theory.
How and why butterflies and fruit flies got their spots, and the fossil record for human evolution.
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.
Dr. Evans reviews how PPARs regulate body weight by controlling whether fat is burned or stored.
Dr. Barbara Meyer explains the value of studying model organisms and introduces the nematode C. elegans.
Having too many chromosomes can lead to too much gene expression. Dr. Meyer explains how the gene that controls dosage compensation in C. elegans works.
After the end of the last ice age 10,000 years ago, populations of marine stickleback fish became stranded in freshwater lakes dotted throughout the Northern Hemisphere in places of natural beauty like Alaska and British Columbia. These remarkable little fish have adapted and thrive, living...
Lactase persistence results from a mutation that changes how transcription factors interact, thereby affecting gene expression.
Learn about how gene switches can control expression of genes in different tissues.
RNA interference is an exciting new research tool for shutting down genes. It could also yield new medical treatments.
These classroom-ready resources complement the short film Evolving Switches, Evolving Bodies, which tells the story of the dramatic transformation of stickleback fish as they adapted to living in freshwater habitats drastically different from the ocean.
To accompany the lecture series Evolution: Constant Change and Common Threads.
Follow human geneticist Spencer Wells, Director of the Genographic Project of the National Geographic Society, as he tracks down the genetic changes associated with the ability to digest lactose as adults, tracing the origin of the trait to less than 10,000 years ago, a time when some human...
Topics include: Gene expression, RNA structure and function, transcription, RNA processing, translation, and post-translational events.