Individual cells are color-coded based on their identity and signaling activity using a protein circuit technology developed by the Coyle Lab. Just as a radio allows you to listen to an individual frequency, this technology allows researchers to tune into the specific “radio station” of each cell through genetically encoded proteins from a bacterial system called MinDE. The proteins generate an oscillating fluorescent signal that transmits information about cell shape, state, and identity that can be decoded using digital signal processing tools originally designed for telecommunications. The approach allows researchers to look at the dynamics of a single cell in the presence of many other cells.

Related to video 7022.

A number of environmental factors cause DNA mutations that can lead to cancer: toxins in cigarette smoke, sunlight and other radiation, and some viruses.

This is a fibroblast, a connective tissue cell that plays an important role in wound healing. Normal fibroblasts have smooth edges. In contrast, this spiky cell is missing a protein that is necessary for proper construction of the cell's skeleton. Its jagged shape makes it impossible for the cell to move normally. In addition to compromising wound healing, abnormal cell movement can lead to birth defects, faulty immune function, and other health problems.

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

The fledgling field of X-ray microscopy lets researchers look inside whole cells rapidly frozen to capture their actions at that very moment. Here, a yeast cell buds before dividing into two. Colors show different parts of the cell. Seeing whole cells frozen in time will help scientists observe cells' complex structures and follow how molecules move inside them.

Learn about how bacteria and viruses differ, how they each can make you sick, and how they can or cannot be treated. Discover more resources from NIGMS’ Pathways collaboration with Scholastic. View the video on YouTube for closed captioning.

A colony of human embryonic stem cells (light blue) grows on fibroblasts (dark blue).

The membrane that surrounds a cell is made up of proteins and lipids. Depending on the membrane's location and role in the body, lipids can make up anywhere from 20 to 80 percent of the membrane, with the remainder being proteins. Cholesterol (green), which is not found in plant cells, is a type of lipid that helps stiffen the membrane.

What looks like the gossamer wings of a butterfly is actually the retina of a mouse, delicately snipped to lay flat and sparkling with fluorescent molecules. The image is from a research project investigating the promise of gene therapy for glaucoma. It was created at an NIGMS-funded advanced microscopy facility that develops technology for imaging across many scales, from whole organisms to cells to individual molecules.

The ability to obtain high-resolution imaging of tissue as large as whole mouse retinas was made possible by a technique called large-scale mosaic confocal microscopy, which was pioneered by the NIGMS-funded National Center for Microscopy and Imaging Research. The technique is similar to Google Earth in that it computationally stitches together many small, high-resolution images.

Cells use bubble-like structures called vesicles (yellow) to import, transport, and export cargo and in cellular communication. A single cell may be filled with thousands of moving vesicles.

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

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.

Two models for how material passes through the Golgi apparatus: the vesicular shuttle model and the cisternae maturation model.

Cdc42, a member of the Rho family of small guanosine triphosphatase (GTPase) proteins, regulates multiple cell functions, including motility, proliferation, apoptosis, and cell morphology. In order to fulfill these diverse roles, the timing and location of Cdc42 activation must be tightly controlled. Klaus Hahn and his research group use special dyes designed to report protein conformational changes and interactions, here in living neutrophil cells. Warmer colors in this image indicate higher levels of activation. Cdc42 looks to be activated at cell protrusions.

Related to images 2452, 2453, and 2454.

Bean-shaped mitochondria are cells' power plants. These organelles have their own DNA and replicate independently. The highly folded inner membranes are the site of energy generation.

Cross-section of skin anatomy shows layers and different tissue types.

A peripheral nerve cell made from human embryonic stem cell-derived neural crest stem cells. The nucleus is shown in blue, and nerve cell proteins peripherin and beta-tubulin (Tuj1) are shown in green and red, respectively. Related to image 3263.

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.

Cells move forward with lamellipodia and filopodia supported by networks and bundles of actin filaments. Proper, controlled cell movement is a complex process. Recent research has shown that an actin-polymerizing factor called the Arp2/3 complex is the key component of the actin polymerization engine that drives amoeboid cell motility. ARPC3, a component of the Arp2/3 complex, plays a critical role in actin nucleation. In this photo, the ARPC3+/+ fibroblast cells were fixed and stained with Alexa 546 phalloidin for F-actin (red), mDia1 (green), and DAPI to visualize the nucleus (blue). mDia1 is localized at the lamellipodia of ARPC3+/+ fibroblast cells. Related to images 3328, 3329, 3331, 3332, and 3333.

Wound healing requires the action of stem cells. In mice that lack the Sept2/ARTS gene, stem cells involved in wound healing live longer and wounds heal faster and more thoroughly than in normal mice. This confocal microscopy image from a mouse lacking the Sept2/ARTS gene shows a tail wound in the process of healing. See more information in the article in Science.

Related to images 3497 and 3498.

This image 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 image 5868 and video 5843

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.

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 6553 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.

The nucleus of a human fibroblast cell with chromatin—a substance made up of DNA and proteins—shown in various colors. Fibroblasts are one of the most common types of cells in mammalian connective tissue, and they play a key role in wound healing and tissue repair. This image was captured using Stochastic Optical Reconstruction Microscopy (STORM).

Related to images 6888 and 6893.

2.5Å resolution reconstruction of rabbit muscle aldolase collected on a FEI/Thermo Fisher Titan Krios with energy filter and image corrector.

Fruit fly sperm cells glow bright green when they express the gene for green fluorescent protein (GFP).

Fluorescent markers show the interconnected web of tubes and compartments in the endoplasmic reticulum. The protein atlastin helps build and maintain this critical part of cells. The image is from a July 2009 news release.

This image mostly shows normal cultured epithelial cells expressing green fluorescent protein targeted to the Golgi apparatus (yellow-green) and stained for actin (magenta) and DNA (cyan). The middle cell is an abnormal large multinucleated cell. All the cells in this image have a Golgi but not all are expressing the targeted recombinant fluorescent protein.

These mitochondria (brown) are from the heart muscle cell of a rat. Mitochondria have an inner membrane that folds in many places (and that appears here as striations). This folding vastly increases the surface area for energy production. Nearly all our cells have mitochondria. Related to image 3661.

Human cells with the gene that codes for the protein FIT2 deleted. Green indicates an endoplasmic reticulum (ER) resident protein. The lack of FIT2 affected the structure of the ER and caused the resident protein to cluster in ER membrane aggregates, seen as large, bright-green spots. Red shows where the degradation of cell parts—called autophagy—is taking place, and the nucleus is visible in blue. This image was captured using a confocal microscope.

A crane fly spermatocyte during metaphase of meiosis-I, a step in the production of sperm. A meiotic spindle pulls apart three pairs of autosomal chromosomes, along with a sex chromosome on the right. Tubular mitochondria surround the spindle and chromosomes. This video was captured with quantitative orientation-independent differential interference contrast and is a time lapse showing a 1-second image taken every 30 seconds over the course of 30 minutes.

More information about the research that produced this video can be found in the J. Biomed Opt. paper “Orientation-Independent Differential Interference Contrast (DIC) Microscopy and Its Combination with Orientation-Independent Polarization System” by Shribak et. al.

Ovarioles in female insects are tubes in which egg cells (called oocytes) form at one end and complete their development as they reach the other end of the tube. This image, taken with a confocal microscope, shows ovarioles in a very popular lab animal, the fruit fly Drosophila. The basic structure of ovarioles supports very rapid egg production, with some insects (like termites) producing several thousand eggs per day. Each insect ovary typically contains four to eight ovarioles, but this number varies widely depending on the insect species.

Scientists use insect ovarioles, for example, to study the basic processes that help various insects, including those that cause disease (like some mosquitos and biting flies), reproduce very quickly.

The HIV capsid is a pear-shaped structure that is made of proteins the virus needs to mature and become infective. The capsid is inside the virus and delivers the virus' genetic information into a human cell. To better understand how the HIV capsid does this feat, scientists have used computer programs to simulate its assembly. This image shows a series of snapshots of the steps that grow the HIV capsid. A model of a complete capsid is shown on the far right of the image for comparison; the green, blue and red colors indicate different configurations of the capsid protein that make up the capsid “shell.” The bar in the left corner represents a length of 20 nanometers, which is less than a tenth the size of the smallest bacterium. Computer models like this also may be used to reconstruct the assembly of the capsids of other important viruses, such as Ebola or the Zika virus. The studies reporting this research were published in Nature Communications and Nature. To learn more about how researchers used computer simulations to track the assembly of the HIV capsid, see this press release from the University of Chicago.

A 3D model of the human endoplasmic reticulum membrane protein complex (EMC) that identifies its nine essential subunits. The EMC plays an important role in making membrane proteins, which are essential for all cellular processes. This is the first atomic-level depiction of the EMC. Its structure was obtained using single-particle cryo-electron microscopy.

Fruit flies are a common model organism for basic medical research.

Cultured hippocampal neurons grown on a substrate of glial cells (astrocytes). The glial cells form the pink/brown underlayment in this image. The tan threads are the neurons. The round tan balls are synapses, the points where neurons meet and communicate with each other. The cover slip underlying the cells is green. Neurons in culture can be used to study synaptic plasticity, activity-dependent protein turnover, and other topics in neuroscience.

These microscopic roundworms, called Caenorhabditis elegans, lack eyes and the opsin proteins used by visual systems to detect colors. However, researchers found that the worms can still sense the color of light in a way that enables them to avoid pigmented toxins made by bacteria. This image was captured using a stereo microscope.

Scientists in Scotland were the first to clone an animal, this sheep named Dolly. She later gave birth to Bonnie, the lamb next to her.

A computer model shows how the endoplasmic reticulum is close to and almost wraps around mitochondria in the cell. The endoplasmic reticulum is lime green and the mitochondria are yellow. This image relates to a July 27, 2009 article in Computing Life.

A light microscope image of a cell from the endosperm of an African globe lily (Scadoxus katherinae). This is one frame of a time-lapse sequence that shows cell division in action. The lily is considered a good organism for studying cell division because its chromosomes are much thicker and easier to see than human ones. Staining shows microtubules in red and chromosomes in blue. Here, condensed chromosomes are clearly visible.

Related to images 1010, 1011, 1012, 1013, 1014, 1016, 1017, 1018, 1019, and 1021.

Learn how research organisms, such as fruit flies and mice, can help us understand and treat human diseases. Discover more resources from NIGMS’ Pathways collaboration with Scholastic. View the video on YouTube for closed captioning.

Bacteria engineered to act as genetic clocks flash in synchrony. Here, a "supernova" burst in a colony of coupled genetic clocks just after reaching critical cell density. Superimposed: A diagram from the notebook of Christiaan Huygens, who first characterized synchronized oscillators in the 17th century.

Actin is an essential protein in a cell's skeleton (cytoskeleton). It forms a dense network of thin filaments in the cell. Here, researchers have used a technique called stochastic optical reconstruction microscopy (STORM) to visualize the actin network in a cell in three dimensions. The actin strands were labeled with a dye called Alexa Fluor 647-phalloidin.  This image appears in a study published by Nature Methods, which reports how researchers use STORM to visualize the cytoskeleton.

Cdc42, a member of the Rho family of small guanosine triphosphatase (GTPase) proteins, regulates multiple cell functions, including motility, proliferation, apoptosis, and cell morphology. In order to fulfill these diverse roles, the timing and location of Cdc42 activation must be tightly controlled. Klaus Hahn and his research group use special dyes designed to report protein conformational changes and interactions, here in living neutrophil cells. Warmer colors in this image indicate higher levels of activation. Cdc42 looks to be activated at cell protrusions.

Related to images 2451, 2452, and 2453.

Sketch of an egg cell.

Hydra magnipapillata is an invertebrate animal used as a model organism to study developmental questions, for example the formation of the body axis.

Taste buds in a mouse tongue epithelium with types I, II, and III taste cells visualized by cell-type-specific fluorescent antibodies. Type II taste bud cells signal sweet, bitter, and umami tastes to the central nervous system by releasing ATP through the voltage-gated ion channel CALHM1. Researchers used a confocal microscope to capture this image, which shows all taste buds in red, type II taste buds in green, and DNA in blue.

More information about this work can be found in the Nature letter "CALHM1 ion channel mediates purinergic neurotransmission of sweet, bitter and umami tastes” by Taruno et. al.

Scanning electron micrograph of an apoptotic HeLa cell. Zeiss Merlin HR-SEM. See related images 3518, 3520, 3521, 3522.

Image showing rhabdomeres (red), the light-sensitive structures in the fruit fly retina, and rhodopsin-4 (blue), a light-sensing molecule.

Drosophila adult brain showing that an adipokine (fat hormone) generates a response from neurons (aqua) and regulates insulin-producing neurons (red).

Related to images 6982, 6983, and 6984.

A light microscope image shows the chromosomes, stained dark blue, in a dividing cell of an African globe lily (Scadoxus katherinae). This is one frame of a time-lapse sequence that shows cell division in action. The lily is considered a good organism for studying cell division because its chromosomes are much thicker and easier to see than human ones.