Once a gene has been transcribed into messenger RNA (mRNA), it is edited in a process called splicing. Noncoding regions called introns are removed, leaving protein-coding regions called exons.
The first phase of the process of reading DNA information to make proteins starts with a molecule unzipping the DNA. The molecule then copies one of the strands of DNA into a strand of RNA, a close cousin of DNA. This process is called transcription.
The process of copying DNA into messenger RNA (mRNA) is called transcription. Transcription factors assemble at the promoter region of a gene, bringing an RNA polymerase enzyme to form the transcription initiation complex. Activator proteins at the enhancer region of DNA then activate the...
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...
Messenger RNA (mRNA) carries DNA's genetic information to the ribosome, where it is translated into a sequence of amino acids. mRNA is fed into the ribosome, and it is positioned so that it can be read in groups of three letters, known as codons. Each mRNA codon is matched against the transfer...
How a nerve cell gets its identity, sends axons, and makes connections with other cells.
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.
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.
Four lectures highlight the research of two scientists who have made groundbreaking discoveries elucidating the molecular basis of circadian clocks—the internal timekeepers that govern fluctuations in behavior and physiology on a 24-hour cycle.
Although tiny in size, the fruit fly has had a major impact on our understanding of circadian rhythms.
Dr. Rosbash discloses how scientists have persuaded Mother Nature to reveal the inner workings of the fruit fly's biological clock.
Dr. Takahashi describes the powerful strategies that he and others have harnessed for understanding biological clocks in mammals.
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...
Lactose tolerance, sickle cell anemia, and bitter taste perception are three examples of recently evolved human traits.
Understand how quorum sensing works by reasoning through experiments involving genetically-engineered bioluminescent bacteria.
Learn about the different ways scientists are able to detect when genes are being expressed in various tissues.
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.
DNA microarrays, or gene chips, are an important new technology for genomic research. Learn how researchers use computing to analyze and interpret the huge datasets generated by microarray experiments.
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.
A lesson that requires students to transcribe and translate portions of the wild-type and mutant rock pocket mouse Mc1r genes and compare sequences to identify the locations and types of mutations responsible for the coat color variation described in the film.
To accompany the lecture series Evolution: Constant Change and Common Threads.