Search Results

Search Results

Showing 1-60 of 65 Resources
  • Living Together

    Living Together

    Image of the Week

    Flow patterns generated by cilia around the light organ of the Hawaiian bobtail squid (Euprymna scolopes).

  • Identifying the Key Genes for Regeneration

    Identifying the Key Genes for Regeneration

    Scientists at Work

    (9 min 55 sec) Planarians have an amazing ability to regenerate lost tissues. In this video, scientists knock out two different genes in planaria to start to understand how the process works—and they generate animals with two heads and two tails!

  • The Beak of the Fish

    The Beak of the Fish

    Image of the Week

    The teeth of adult pufferfish are fused to form a beak used for crunching into hard prey such as shellfish.

  • Top Notch Model Organism

    Top Notch Model Organism

    Image of the Week

    Close-up of cells in a fruit fly eye at the pupal stage stained with antibodies to the Notch protein.

  • Single Mother

    Single Mother

    Image of the Week

    A queen bee may produce as many as 60,000 offspring during her lifetime.

  • Larval Biscuit

    Larval Biscuit

    Image of the Week

    A pluteus larva of the sea biscuit, Clypeaster subdepressus, an echinoderm closely related to sea urchins.

  • Seeing In the New Year

    Seeing In the New Year

    Image of the Week

    Multi-color labeling of photoreceptor neurons in the developing visual system of the fruit fly (Drosophila melanogaster).

  • Genetic Mutations and Disease Interactive

    Genetic Mutations and Disease Interactive

    Click & Learn

    This interactive focuses on the roles of germline and somatic cell mutations in human disease. It supports the 2013 Holiday Lectures on Science, Medicine in the Genomic Era.

  • Biological Basis of a Myth

    Biological Basis of a Myth

    Image of the Week

    Hydra is a small freshwater hydrozoan polyp that has the capacity to grow a new individual from any part of its body.

  • Zebrafish Brain Cells for Spontaneous Navigation

    Zebrafish Brain Cells for Spontaneous Navigation

    Image of the Week

    The brain and part of the spinal cord of a one-week-old zebrafish, showing neurons that are active during a left turn (green), a right turn (red), or when swimming straight ahead (blue)

  • Colorizing Skin Cells

    Colorizing Skin Cells

    Image of the Week

    The “skinbow” zebrafish has color-coded skin cells when viewed in a microscope using UV light illumination.

  • Unconditional Love

    Unconditional Love

    Image of the Week

    A mother and her baby viewed using magnetic resonance imaging (MRI).

  • The Heart of the Matter

    The Heart of the Matter

    Image of the Week

    Early theories of the heart’s role were largely based on its central position in the body.

  • Reckless Growth

    Reckless Growth

    Image of the Week

    The organization of cells in a healthy mouse intestine is lost in a growing tumor.

  • Synchronized Division

    Synchronized Division

    Image of the Week

    The early embryonic cells of the sand dollar are caught in the act of synchronized cell division.

  • Making the Flow

    Making the Flow

    Image of the Week

    The surface cells of tadpole embryos have cilia that move the water around them.

  • The Embryo Puzzle

    The Embryo Puzzle

    Image of the Week

    A new technique tracks thousands of cells in the fruit fly (Drosophila) embryo during development.

  • Have Your Larva and Eat It Too

    Have Your Larva and Eat It Too

    Image of the Week

    During the larval stage, the Nemertean worm develops inside a hollow sac from which the juvenile eventually emerges, rupturing the sac and then eating the remains.

  • One Bone, Two Bones...

    One Bone, Two Bones...

    Image of the Week

    This short-tailed fruit bat embryo shows a pattern of bones in its limbs characteristic of all tetrapods: one bone, two bones, lots of bones, digits. 

  • Double, Double, Toil and Trouble

    Double, Double, Toil and Trouble

    Image of the Week

    Two views of a late pupa of an unidentified midge species (family Chironomidae).

  • Fish Tales

    Fish Tales

    Image of the Week

    Zebrafish blood is generated from stem cells located in the tail region of fish embryos and later from stem cells located in the kidney of the adult fish.

  • Potent Stem Cells

    Potent Stem Cells

    Poster

    The poster from the 2006 Holiday Lectures on Science, Potent Biology: Stem Cells, Cloning, and Regeneration, illustrates the role of stem cells during human embryonic development.

  • Perfect Daughters

    Perfect Daughters

    Image of the Week

    Chromosomes change form as a cell divides to ensure that each daughter cell gets a full, intact copy of the genome.

  • Dante's Story

    Dante's Story

    Clip

    (6 min 6 sec) Dante is a 10-year-old boy born with hemimegalencephaly—an enlargement of half his brain.

  • The Search for Genetic Mutations that Cause Autism

    The Search for Genetic Mutations that Cause Autism

    Clip

    (2 min 5 sec) Dr. Christopher Walsh discusses how genomic science has made enormous contributions to our understanding of the genetic causes of autism.

  • Meet Dante—A Young Boy with Hemimegalencephaly

    Meet Dante—A Young Boy with Hemimegalencephaly

    Clip

    (2 min 33 sec) Dante is a healthy 10-year-old boy who has had half his cerebral cortex surgically removed to treat his seizures.

  • Development of the Cerebral Cortex

    Development of the Cerebral Cortex

    Animation

    (1 min 43 sec) Most of the neurons of the cerebral cortex arise from progenitor cells that undergo repeated cell division.

  • These Limbs Are Made for Walkin'...

    These Limbs Are Made for Walkin'...

    Image of the Week

    ... but that's not all they'll do. Several genes determine the diverse shapes and functions of crustacean appendages. 

  • Sizing Up the Brain Gene By Gene

    Sizing Up the Brain Gene By Gene

    Lecture

    (59 min 32 sec) Recent advances in DNA sequencing technology have led to a better understanding of the many genes that play a role in brain development.

  • How the Sea Anemone Gets Its Tentacles

    How the Sea Anemone Gets Its Tentacles

    Image of the Week

    The young starlet sea anemone forms tentacles by cell division, migration, and shape changes.   

  • The Eye of a Red-eyed Tree Frog at Rest

    The Eye of a Red-eyed Tree Frog at Rest

    Image of the Week

    Many animals have a third eyelid called a nictitating membrane that protects the eye.

  • Pearls or Stink Bug Eggs?

    Pearls or Stink Bug Eggs?

    Image of the Week

    A group of 14 stink bug eggs attached to the underside of a poplar leaf.

  • Meet Chris Walsh

    Meet Chris Walsh

    Clip

    (2 min 3 sec) Dr. Walsh is an HHMI investigator whose research focuses on understanding the genes involved in the development and function of the human brain.

  • Genetic Mutations and Disease

    Genetic Mutations and Disease

    Poster

    The poster for the 2013 Holiday Lectures on Science, Medicine in the Genomic Era, illustrates the difference between germline and somatic cell mutations.

  • Building Brains: The Molecular Logic of Neural Circuits

    Building Brains: The Molecular Logic of Neural Circuits

    Lecture

    (58 min 29 sec) How a nerve cell gets its identity, sends axons, and makes connections with other cells.

  • Demo: SHH concentration and eye position

    Demo: SHH concentration and eye position

    Clip

    (1 min 22 sec) A reduction in the level of sonic hedgehog (SHH) gene expression can lead to cyclopia.

  • Long-distance neuronal path-finding

    Long-distance neuronal path-finding

    Clip

    (31 sec) Retinal axons travel across the brain, reading navigation cues, to find appropriate targets.

  • Growth cones in action

    Growth cones in action

    Clip

    (34 sec) The growth cones of two neurons sense and interact with one another.

  • Contact repulsion of a growth cone

    Contact repulsion of a growth cone

    Clip

    (1 min 5 sec) A growth cone contacts a repellant molecule on another axon, collapses, and withdraws.

  • Development of the human embryonic brain

    Development of the human embryonic brain

    Animation

    (1 min 40 sec) The fetal brain grows enormously during pregnancy, both in terms of its size and the number of neurons it has.

  • Repellant ephrin signals guide limb innervations

    Repellant ephrin signals guide limb innervations

    Animation

    (1 min 34 sec) The growth cone of a neuron avoids repellant molecules and navigates to innervate the appropriate muscle.

  • Signal molecules trigger transcription factors

    Signal molecules trigger transcription factors

    Animation

    (2 min 4 sec) Varying concentrations of a signaling molecule activate different transcription factors and determine cell fate.

  • Classroom Activities: Stem Cells and Diabetes

    Classroom Activities: Stem Cells and Diabetes

    Activity

    To accompany the lecture series Potent Biology: Stem Cells, Cloning, and Regeneration.

  • Coaxing Embryonic Stem Cells

    Coaxing Embryonic Stem Cells

    Lecture

    (58 min 25 sec) In cloning, a cell's genetic machinery is reprogrammed. Can we similarly coax stem cells to become specific cell types?

  • Understanding Embryonic Stem Cells

    Understanding Embryonic Stem Cells

    Lecture

    (58 min 27 sec) An overview of embryonic development, the progressive differentiation of cells, and properties of embryonic stem cells.

  • Potent Biology: Stem Cells, Cloning, and Regeneration

    Potent Biology: Stem Cells, Cloning, and Regeneration

    Lecture

    Doug Melton and Nadia Rosenthal are leaders in stem cell research, working primarily with mouse and human tissue. They will discuss where embryonic and adult stem cells come from and the biology of how they supply the cells the body needs.

  • Planarian Regeneration and Stem Cells

    Planarian Regeneration and Stem Cells

    Scientists at Work

    (11 min 47 sec) A mini-documentary discussing the remarkable regenerative capabilities of the planarian, and how HHMI researcher Alejandro Sánchez Alvarado uses them to study the biology of stem cells.

  • Human Embryonic Development

    Human Embryonic Development

    Animation

    (2 min 18 sec) Human embryonic development depends on stem cells. During the course of development, cells divide, migrate, and specialize. Early in development, a group of cells called the inner cell mass (ICM) forms. These cells are able to produce all the tissues of the body. Later in development, during gastrulation, the three germ layers form, and most cells become more restricted in the types of cells that they can produce.

  • Differentiation and the Fate of Cells

    Differentiation and the Fate of Cells

    Animation

    (1 min 29 sec) As a human embryo develops, its cells become progressively restricted in the types of specialized cells that they can produce. Inner cell mass (ICM) cells of the blastocyst can make any type of body cell. Gastrula-stage cells can give rise to the cells of a given germ layer. Later, cells become even more restricted. For example, the pancreatic bud of the endoderm layer can only make the cells of the pancreas.

  • Cytoplasmic Factors

    Cytoplasmic Factors

    Animation

    (57 sec) Cytoplasmic factors play a significant part in determining how a cell develops. This segment discusses their importance in turning the appropriate genes on and off for proper development.

  • Creating Embryonic Stem Cell Lines

    Creating Embryonic Stem Cell Lines

    Animation

    (1 min 38 sec) 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.

  • Somatic Cell Nuclear Transfer Animation

    Somatic Cell Nuclear Transfer Animation

    Animation

    (52 sec) Somatic cell nuclear transfer (SCNT) is a technique for cloning. The nucleus is removed from a healthy egg. This egg becomes the host for a nucleus that is transplanted from another cell, such as a skin cell. The resulting embryo can be used to generate embryonic stem cells with a genetic match to the nucleus donor (therapeutic cloning), or can be implanted into a surrogate mother to create a cloned individual, such as Dolly the sheep (reproductive cloning).

  • Classroom Activities: Gene Switches

    Classroom Activities: Gene Switches

    Activity

    To accompany the lecture series Evolution: Constant Change and Common Threads.

  • Pitx1 Expression

    Pitx1 Expression

    Animation

    (55 sec) 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 regulatory switch that normally turns on the Pitx1 gene is either missing or non-functional.

  • Rett Syndrome

    Rett Syndrome

    Clip

    (2 min 52 sec) Dr. Zoghbi introduces the topic of Rett syndrome by showing how development usually progresses in a young girl. She then shows an excerpt from Silent Angels, introduced by Julia Roberts, which shows how Rett syndrome affects development.

  • X Inactivation

    X Inactivation

    Animation

    (55 sec) 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. 

  • Deciphering the Language of Sex

    Deciphering the Language of Sex

    Lecture

    (58 min 51 sec) Is it a boy or a girl? Dr. David Page looks at how we define male and female and summarizes the development of human sex characteristics.

  • Sperm Motility

    Sperm Motility

    Clip

    (21 sec) Video microscopy of sperm motility in an average human male and an infertile male.

  • Intracytoplasmic Sperm Injection (ICSI)

    Intracytoplasmic Sperm Injection (ICSI)

    Clip

    (1 min 16 sec) Video microscopy demonstrating how sperm from an infertile male can be injected into a female egg.

  • From Fertilization to Egg Laying in C. elegans

    From Fertilization to Egg Laying in C. elegans

    Clip

    (1 min 12 sec) Video of the fertilization of the C. elegans oocyte, the fusion of the egg and sperm nuclei, and the egg laying.

Refine Results

Narrow your choices by selecting areas below.

Topics