Cell-like compartments spontaneously emerge from scrambled frog eggs, with nuclei (blue) from frog sperm. Endoplasmic reticulum (red) and microtubules (green) are also visible. Video created using epifluorescence microscopy.

For more photos of cell-like compartments from frog eggs view: 6584, 6585, 6586, 6591, 6592, and 6593.

For videos of cell-like compartments from frog eggs view: 6588, 6589, and 6590.

By attaching fluorescent proteins to the genetic circuit responsible for B. subtilis's stress response, researchers can observe the cells' pulses as green flashes. This video shows flashing cells as they multiply over the course of more than 12 hours. In response to a stressful environment like one lacking food, B. subtilis activates a large set of genes that help it respond to the hardship. Instead of leaving those genes on as previously thought, researchers discovered that the bacteria flip the genes on and off, increasing the frequency of these pulses with increasing stress. See entry 3253 for a related still image.

This image is a computer-generated model of the approximately 4.2 million atoms of the HIV capsid, the shell that contains the virus' genetic material. Scientists determined the exact structure of the capsid and the proteins that it's made of using a variety of imaging techniques and analyses. They then entered these data into a supercomputer that produced the atomic-level image of the capsid. This structural information could be used for developing drugs that target the capsid, possibly leading to more effective therapies. Related to image 6601.

Developing fruit fly spermatids require caspase activity (green) for the elimination of unwanted organelles and cytoplasm via apoptosis.

Real-time footage of Caenorhabditis elegans, a tiny roundworm, trapped by a carnivorous fungus, Arthrobotrys dactyloides. This fungus makes ring traps in response to the presence of C. elegans. When a worm enters a ring, the trap rapidly constricts so that the worm cannot move away, and the fungus then consumes the worm. The size of the imaged area is 0.7mm x 0.9mm.

This video was obtained with a polychromatic polarizing microscope (PPM) in white light that shows the polychromatic birefringent image with hue corresponding to the slow axis orientation. More information about PPM can be found in the Scientific Reports paper “Polychromatic Polarization Microscope: Bringing Colors to a Colorless World” by Shribak.

Model of a major secreted protein of unknown function, which is only found in mycobacteria, the class of bacteria that causes tuberculosis. Based on structural similarity, this protein may be involved in host-bacterial interactions.

A mouse brain that was genetically modified so that subpopulations of its neurons glow. Researchers often study mice because they share many genes with people and can shed light on biological processes, development, and diseases in humans.

This image was captured using a light sheet microscope.

Related to image 6929 and video 6931.

Proteins in the neural tissues of this zebrafish embryo direct cells to line up and form the neural tube, which will become the spinal cord and brain. Studies of zebrafish embryonic development may help pinpoint the underlying cause of common neural tube defects--such as spina bifida--which occur in about 1 in 1,000 newborn children.

Model of the mandelate racemase enzyme from Bacillus subtilis, a bacterium commonly found in soil.

Ecteinascidin 743 (ET-743, brand name Yondelis), was discovered and isolated from a sea squirt, Ecteinascidia turbinata, by NIGMS grantee Kenneth Rinehart at the University of Illinois. It was synthesized by NIGMS grantees E.J. Corey and later by Samuel Danishefsky. Multiple versions of this structure are available as entries 2790-2797.

In the top snapshots, the brain of a sleep-deprived fruit fly glows orange, marking high concentrations of a synaptic protein called Bruchpilot (BRP) involved in communication between neurons. The color particularly lights up brain areas associated with learning. By contrast, the bottom images from a well-rested fly show lower levels of the protein. These pictures illustrate the results of an April 2009 study showing that sleep reduces the protein's levels, suggesting that such "downscaling" resets the brain to normal levels of synaptic activity and makes it ready to learn after a restful night.

Proteins are long chains of amino acids. Each protein has a unique amino acid sequence. It is still a mystery how a protein folds into the proper shape based on its sequence. Scientists hope that one day they can "watch" this folding process for any given protein. The dream has been realized, at least partially, through the use of computer simulation.

A study published in March 2012 used cryo-electron microscopy to determine the structure of the DNA replication origin recognition complex (ORC), a semi-circular, protein complex (yellow) that recognizes and binds DNA to start the replication process. The ORC appears to wrap around and bend approximately 70 base pairs of double stranded DNA (red and blue). Also shown is the protein Cdc6 (green), which is also involved in the initiation of DNA replication. The video shows the structure from different angles. See related image 3597.

In the absence of the engulfment receptor Draper, salivary gland cells (light blue) persist in the thorax of a developing Drosophila melanogaster pupa. See image 2758 for a cross section of a normal pupa that does express Draper.

NIGMS staff are located in the Natcher Building on the NIH campus.

Crystals of hen egg lysozyme protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

Like a world of its own, this sphere represents all the known chemical reactions in the E. coli bacterium. The colorful circles on the surface symbolize sets of densely interconnected reactions. The lines between the circles show additional connecting reactions. The shapes inside the circles are landmark molecules, like capital cities on a map, that either act as hubs for many groups of reactions, are highly conserved among species, or both. Molecules that connect far-flung reactions on the sphere are much more conserved during evolution than molecules that connect reactions within a single circle. This statistical cartography could reveal insights about other complex systems, such as protein interactions and gene regulation networks.

A genetic disorder of the nervous system, neurofibromatosis causes tumors to form on nerves throughout the body, including a type of tumor called an optic nerve glioma that can result in childhood blindness. The image was used to demonstrate the unique imaging capabilities of one of our newest (at the time) laser scanning microscopes and is of a wildtype (normal) mouse retina in the optic fiber layer. This layer is responsible for relaying information from the retina to the brain and was fluorescently stained to reveal the distribution of glial cells (green), DNA and RNA in the cell bodies of the retinal ganglion neurons (orange) and their optic nerve fibers (red), and actin in endothelial cells surrounding a prominent branching blood vessel (blue). By studying the microscopic structure of normal and diseased retina and optic nerves, we hope to better understand the altered biology of the tissues in these tumors with the prospects of developing therapeutic interventions.

Various views of a mouse brain that was genetically modified so that subpopulations of its neurons glow. Researchers often study mice because they share many genes with people and can shed light on biological processes, development, and diseases in humans.

This video was captured using a light sheet microscope.

Related to images 6929 and 6930.

The G switch allows our bodies to respond rapidly to hormones. G proteins act like relay batons to pass messages from circulating hormones into cells. A hormone (red) encounters a receptor (blue) in the membrane of a cell. Next, a G protein (green) becomes activated and makes contact with the receptor to which the hormone is attached. Finally, the G protein passes the hormone's message to the cell by switching on a cell enzyme (purple) that triggers a response. See image 2536 and 2537 for other versions of this image. Featured in Medicines By Design.

In vivo vascular development in kdr:GFP frogs. Related to images 3403 and 3405.

A 3D reconstruction, created using cryo-electron microscopy, of an ion channel known as the full-length serotonin receptor in complex with the antinausea drug granisetron (orange). Ion channels are proteins in cell membranes that help regulate many processes.

Drugs enter different layers of skin via intramuscular, subcutaneous, or transdermal delivery methods. See image 2532 for a labeled version of this illustration. Featured in Medicines By Design.

3D reconstructions of two stages in the assembly of the bacterial ribosome created from time-resolved cryo-electron microscopy images. Ribosomes translate genetic instructions into proteins.

Glide across an icy canyon, where you see smiling snowmen and waddling penguins. Toss a snowball, hear it smash against an igloo, and then watch it explode in bright colors. Psychologists David Patterson and Hunter Hoffman of the University of Washington in Seattle developed this virtual "Snow World" to test whether immersing someone in a pretend reality could ease pain during burn treatment and other medical procedures. They found that people fully engaged in the virtual reality experience reported 60 percent less pain. The technology offers a promising way to manage pain.

Ecteinascidin 743 (ET-743, brand name Yondelis), was discovered and isolated from a sea squirt, Ecteinascidia turbinata, by NIGMS grantee Kenneth Rinehart at the University of Illinois. It was synthesized by NIGMS grantees E.J. Corey and later by Samuel Danishefsky. Multiple versions of this structure are available as entries 2790-2797.

The feeding tube, or pharynx, of a planarian worm with cilia shown in red and muscle fibers shown in green

A crystal of hen egg lysozyme protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

Hippocampal cells in culture with a neuron in green, showing hundreds of the small protrusions known as dendritic spines. The dendrites of other neurons are labeled in blue, and adjacent glial cells are shown in red.

Salk researchers captured the structure of a protein complex called an intasome (center) that lets viruses similar to HIV establish permanent infection in their hosts. The intasome hijacks host genomic material, DNA (white) and histones (beige), and irreversibly inserts viral DNA (blue). The image was created by Jamie Simon and Dmitry Lyumkis. Work that led to the 3D map was published in: Ballandras-Colas A, Brown M, Cook NJ, Dewdney TG, Demeler B, Cherepanov P, Lyumkis D, & Engelman AN. (2016). Cryo-EM reveals a novel octameric integrase structure for ?-retroviral intasome function. Nature, 530(7590), 358—361

X-ray co-crystal structure of Src kinase bound to a DNA-templated macrocycle inhibitor. Related to images 3413, 3414, 3415, 3416, 3418, and 3419.

This video simulation shows what an uncontrolled outbreak of transmissible avian flu among people living in Thailand might look like. Red indicates new cases while green indicates areas where the epidemic has finished. The video shows the spread of infection and recovery over 300 days in Thailand and neighboring countries.

Floral pattern emerging as two bacterial species, motile Acinetobacter baylyi (red) and non-motile Escherichia coli (green), are grown together for 48 hours on 1% agar surface from a small inoculum in the center of a Petri dish.

See 6557 for a photo of this process at 24 hours on 0.75% agar surface.
See 6555 for another photo of this process at 48 hours on 1% agar surface.
See 6556 for a photo of this process at 72 hours on 0.5% agar surface.
See 6550 for a video of this process.

Under the microscope, an E. coli cell lights up like a fireball. Each bright dot marks a surface protein that tells the bacteria to move toward or away from nearby food and toxins. Using a new imaging technique, researchers can map the proteins one at a time and combine them into a single image. This lets them study patterns within and among protein clusters in bacterial cells, which don't have nuclei or organelles like plant and animal cells. Seeing how the proteins arrange themselves should help researchers better understand how cell signaling works.

This fruit fly spermatid recycles various molecules, including malformed or damaged proteins. Actin filaments (red) in the cell draw unwanted proteins toward a barrel-shaped structure called the proteasome (green clusters), which degrades the molecules into their basic parts for re-use.

Cell-like compartments that spontaneously emerged from scrambled frog eggs, with nuclei (blue) from frog sperm. Endoplasmic reticulum (red) and microtubules (green) are also visible. Regions without nuclei formed smaller compartments. Image created using epifluorescence microscopy.

For more photos of cell-like compartments from frog eggs view: 6584, 6586, 6591, 6592, and 6593.

For videos of cell-like compartments from frog eggs view: 6587, 6588, 6589, and 6590.

This image shows the hierarchical ontology of genes, cellular components and processes derived from large genomic datasets. From Dutkowski et al. A gene ontology inferred from molecular networks Nat Biotechnol. 2013 Jan;31(1):38-45. Related to 3436.

An adult Hawaiian bobtail squid, Euprymna scolopes, (~4 cm) surrounded by newly hatched juveniles (~2 mm) in a bowl of seawater.

Related to image 7011 and video 7012.

DNA encodes RNA, which encodes protein. DNA is transcribed to make messenger RNA (mRNA). The mRNA sequence (dark red strand) is complementary to the DNA sequence (blue strand). On ribosomes, transfer RNA (tRNA) reads three nucleotides at a time in mRNA to bring together the amino acids that link up to make a protein. See image 2548 for a version of this illustration that isn't numbered and 2547 for a an entirely unlabeled version. Featured in The New Genetics.

The brain sections are treated with fluorescent antibodies specific to a particular protein and visualized using serial electron microscopy (SEM).

HIV is a retrovirus, a type of virus that carries its genetic material not as DNA but as RNA. Long before anyone had heard of HIV, researchers in labs all over the world studied retroviruses, tracing out their life cycle and identifying the key proteins the viruses use to infect cells. When HIV was identified as a retrovirus, these studies gave AIDS researchers an immediate jump-start. The previously identified viral proteins became initial drug targets. See images 2513 and 2514 for other versions of this illustration. Featured in The Structures of Life.

DNA encodes RNA, which encodes protein. DNA is transcribed to make messenger RNA (mRNA). The mRNA sequence (dark red strand) is complementary to the DNA sequence (blue strand). On ribosomes, transfer RNA (tRNA) reads three nucleotides at a time in mRNA to bring together the amino acids that link up to make a protein. See image 2549 for a numbered version of this illustration and 2547 for an unlabeled version. Featured in The New Genetics.

This montage of tiny, transparent C. elegans--or roundworms--may offer insight into understanding human infertility. Researchers used fluorescent dyes to label the worm cells and watch the process of sex cell division, called meiosis, unfold as nuclei (blue) move through the tube-like gonads. Such visualization helps the scientists identify mechanisms that enable these roundworms to reproduce successfully. Because meiosis is similar in all sexually reproducing organisms, what the scientists learn could apply to humans.

This image shows a normal fibroblast, a type of cell that is common in connective tissue and frequently studied in research labs. This cell has a healthy skeleton composed of actin (red) and microtubles (green). Actin fibers act like muscles to create tension and microtubules act like bones to withstand compression.

This image was part of the Life: Magnified exhibit that ran from June 3, 2014, to January 21, 2015, at Dulles International Airport.

X-ray co-crystal structure of Src kinase bound to a DNA-templated macrocycle inhibitor. Related to 3413, 3415, 3416, 3417, 3418, and 3419.

This video results from a research project to visualize which regions of the adult fruit fly (Drosophila) brain derive from each neural stem cell. First, researchers collected several thousand fruit fly larvae and fluorescently stained a random stem cell in the brain of each. The idea was to create a population of larvae in which each of the 100 or so neural stem cells was labeled at least once. When the larvae grew to adults, the researchers examined the flies’ brains using confocal microscopy. With this technique, the part of a fly’s brain that derived from a single, labeled stem cell “lights up.” The scientists photographed each brain and digitally colorized its lit-up area. By combining thousands of such photos, they created a three-dimensional, color-coded map that shows which part of the Drosophila brain comes from each of its ~100 neural stem cells. In other words, each colored region shows which neurons are the progeny or “clones” of a single stem cell. This work established a hierarchical structure as well as nomenclature for the neurons in the Drosophila brain. Further research will relate functions to structures of the brain.

Related to images 5838 and 5868.

Influenza (flu) virus proteins in the act of self-replication. Viral nucleoprotein (blue) encapsidates [encapsulates] the RNA genome (green). The influenza virus polymerase (orange) reads and copies the RNA genome. In the background is an image of influenza virus ribonucleoprotein complexes observed using cryo-electron microscopy. This image is from a November 2012 News Release.

Image showing that the edge zone (top of image) of the quail embryo shows no proliferating cells (cyan), unlike the interior zone (bottom of image). Non-proliferating cell nuclei are labeled green. This image was obtained as part of a study to understand cell migration in embryos. More specifically, cell proliferation at the edge of the embryo was studied by examining the cellular uptake of a chemical compound called BrDU, which incorporates into the DNA during the S-phase of the cell cycle. Here, the cells that are positive for BrDU uptake are labeled in cyan, while other non-proliferating cell nuclei are labeled green. Notice that the vast majority of BrDU+ cells are located far away from the edge, indicating that edge cells are mostly non-proliferating. An NIGMS grant to Professor Garcia was used to purchase the confocal microscope that collected this image. Related to image 2807 and video 2809.

High-resolution time lapse of epithelial (skin) cell migration and wound healing. It shows an image taken every 13 seconds over the course of almost 14 minutes. The images were captured with quantitative orientation-independent differential interference contrast (DIC) microscope (left) and a conventional DIC microscope (right).

More information about the research that produced this video can be found in the Journal of Microscopy paper “An Orientation-Independent DIC Microscope Allows High Resolution Imaging of Epithelial Cell Migration and Wound Healing in a Cnidarian Model” by Malamy and Shribak.