A large number of proteins interact with the hormone insulin as it is produced in and secreted from the beta cells of the pancreas. In this image, the interactions of TMEM24 protein (green) and insulin (red) in pancreatic beta cells are shown in yellow. More information about the research behind this image can be found in a Biomedical Beat Blog posting from November 2013.

The largest human cell (by volume) is the egg. Human eggs are 150 micrometers in diameter and you can just barely see one with a naked eye. In comparison, consider the eggs of chickens...or ostriches!

This illustration shows pathogenic bacteria behave like a Trojan horse: switching from antibiotic susceptibility to resistance during infection. Salmonella are vulnerable to antibiotics while circulating in the blood (depicted by fire on red blood cell) but are highly resistant when residing within host macrophages. This leads to treatment failure with the emergence of drug-resistant bacteria.

This image was chosen as a winner of the 2016 NIH-funded research image call, and the research was funded in part by NIGMS.

Scientists from Argonne National Laboratory's Advanced Photon Source (APS) display the first X-ray diffraction pattern obtained from a protein crystal using a split X-ray beam, the first of its kind at APS. The scientists shown are (from left to right): Oleg Makarov, Ruslan Sanishvili, Robert Fischetti (project manager), Sergey Stepanov, and Ward Smith.

Amid a network of blood vessels and star-shaped support cells, neurons in the brain signal each other. The mists of color show the flow of important molecules like glucose and oxygen. This image is a snapshot from a 52-second simulation created by an animation artist. Such visualizations make biological processes more accessible and easier to understand.

Crystals of fungal lipase protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

Body organs such as the liver and kidneys process chemicals and toxins. These "target" organs are susceptible to damage caused by these substances. See image 2496 for an unlabeled version of this illustration.

A section of mouse colon with gut bacteria (center, in green) residing within a protective pocket. Understanding how microorganisms colonize the gut could help devise ways to correct for abnormal changes in bacterial communities that are associated with disorders like inflammatory bowel disease.

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.

This image shows hundreds of human embryonic stem cells in various stages of differentiating into neurons. Some cells have become neurons (red), while others are still precursors of nerve cells (green). The yellow is an imaging artifact resulting when cells in both stages are on top of each other. Image and caption information courtesy of the California Institute for Regenerative Medicine.

A crystal of bovine milk alpha-lactalbumin protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

The head of an axolotl—a type of salamander—that has been genetically modified so that its developing nervous system glows purple and its Schwann cell nuclei appear light blue. Schwann cells insulate and provide nutrients to peripheral nerve cells. Researchers often study axolotls for their extensive regenerative abilities. They can regrow tails, limbs, spinal cords, brains, and more. The researcher who took this image focuses on the role of the peripheral nervous system during limb regeneration.

This image was captured using a light sheet microscope.

Related to images 6928 and 6932.

Various views of a zebrafish head with blood vessels shown in purple. Researchers often study zebrafish because they share many genes with humans, grow and reproduce quickly, and have see-through eggs and embryos, which make it easy to study early stages of development.

This video was captured using a light sheet microscope.

Related to image 6934.

Model of aspartoacylase, a human enzyme involved in brain metabolism.

Cells progress through a cycle that consists of phases for growth (blue, green, yellow) and division (red). Cells become quiescent when they exit this cycle (purple). See image 2499 for a labeled version of this illustration.

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

Three-dimensional image of misfolded proteins (green) within mitochondria (red). Related to image 5878. Learn more in this press release by The American Association for the Advancement of Science.

A mosquito larva with genes edited by CRISPR. The red-orange glow is a fluorescent protein used to track the edits. This species of mosquito, Culex quinquefasciatus, can transmit West Nile virus, Japanese encephalitis virus, and avian malaria, among other diseases. The researchers who took this image developed a gene-editing toolkit for Culex quinquefasciatus that could ultimately help stop the mosquitoes from spreading pathogens. The work is described in the Nature Communications paper "Optimized CRISPR tools and site-directed transgenesis towards gene drive development in Culex quinquefasciatus mosquitoes" by Feng et al. Related to image 6770 and video 6771.

A research mentor (Lori Eidson) and student (Nina Waldron, on the microscope) were 2009 members of the BRAIN (Behavioral Research Advancements In Neuroscience) program at Georgia State University in Atlanta. This program is an undergraduate summer research experience funded in part by NIGMS.

A crystal of pig trypsin protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

Collecting and transporting cellular waste and sorting it into recylable and nonrecylable pieces is a complex business in the cell. One key player in that process is the endosome, which helps collect, sort and transport worn-out or leftover proteins with the help of a protein assembly called the endosomal sorting complexes for transport (or ESCRT for short). These complexes help package proteins marked for breakdown into intralumenal vesicles, which, in turn, are enclosed in multivesicular bodies for transport to the places where the proteins are recycled or dumped. In this image, two multivesicular bodies (with yellow membranes) contain tiny intralumenal vesicles (with a diameter of only 25 nanometers; shown in red) adjacent to the cell's vacuole (in orange).

Scientists working with baker's yeast (Saccharomyces cerevisiae) study the budding inward of the limiting membrane (green lines on top of the yellow lines) into the intralumenal vesicles. This tomogram was shot with a Tecnai F-20 high-energy electron microscope, at 29,000x magnification, with a 0.7-nm pixel, ~4-nm resolution.

To learn more about endosomes, see the Biomedical Beat blog post The Cell’s Mailroom. Related to a microscopy photograph 5768 that was used to generate this illustration and a zoomed-out version 5769 of this illustration.

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 and are separating to form the cores of two new cells.

Related to images 1011, 1012, 1013, 1014, 1015, 1016, 1017, 1018, 1019, and 1021.

Macrophages (green) are the professional eaters of our immune system. They are constantly surveilling our tissues for targets—such as bacteria, dead cells, or even cancer—and clearing them before they can cause harm. In this image, researchers were testing how macrophages responded to different molecules that were attached to silica beads (magenta) coated with a lipid bilayer to mimic a cell membrane.

Find more information on this image in the NIH Director’s Blog post "How to Feed a Macrophage."

DNA consists of two long, twisted chains made up of nucleotides. Each nucleotide contains one base, one phosphate molecule, and the sugar molecule deoxyribose. The bases in DNA nucleotides are adenine, thymine, cytosine, and guanine. See image 2541 for an unlabeled version of this illustration. Featured in The New Genetics.

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.

3D image of Caulobacter bacterium with various components highlighted: cell membranes (red and blue), protein shell (green), protein factories known as ribosomes (yellow), and storage granules (orange).

A fruit fly ovary, shown here, contains as many as 20 eggs. Fruit flies are not merely tiny insects that buzz around overripe fruit—they are a venerable scientific tool. Research on the flies has shed light on many aspects of human biology, including biological rhythms, learning, memory, and neurodegenerative diseases. Another reason fruit flies are so useful in a lab (and so successful in fruit bowls) is that they reproduce rapidly. About three generations can be studied in a single month.

Related to image 3656. This image was part of the Life: Magnified exhibit that ran from June 3, 2014, to January 21, 2015, at Dulles International Airport.

This fused chromosome has two functional centromeres, shown as two sets of red and green dots. Centromeres are DNA/protein complexes that are key to splitting the chromosomes evenly during cell division. When dicentric chromosomes like this one are formed in a person, fertility problems or other difficulties may arise. Normal chromosomes carrying a single centromere (one set of red and green dots) are also visible in this image.

Crystals of fungal lipase protein created for X-ray crystallography, which can reveal detailed, three-dimensional protein structures.

The photo shows a confocal microscopy image of perineuronal nets (PNNs), which are specialized extracellular matrix (ECM) structures in the brain. The PNN surrounds some nerve cells in brain regions including the cortex, hippocampus and thalamus. Researchers study the PNN to investigate their involvement stabilizing the extracellular environment and forming nets around nerve cells and synapses in the brain. Abnormalities in the PNNs have been linked to a variety of disorders, including epilepsy and schizophrenia, and they limit a process called neural plasticity in which new nerve connections are formed. To visualize the PNNs, researchers labeled them with Wisteria floribunda agglutinin (WFA)-fluorescein. Related to image 3741.

Neuron from a crab showing the cell body (bottom), axon (rope-like extension), and growth cone (top right).

Cross section of human skeletal muscle. Image taken with a confocal fluorescent light microscope.

Detailed three-dimensional reconstruction of a tubular matrix in a thin section of the peripheral endoplasmic reticulum between the plasma membranes of the cell.
The endoplasmic reticulum (ER) is a continuous membrane that extends like a net from the envelope of the nucleus outward to the cell membrane. The ER plays several roles within the cell, such as in protein and lipid synthesis and transport of materials between organelles.
Shown here is a three-dimensional representation of the peripheral ER microtubules. Related to images 5855 and 5856

This structure from an amyloid-forming prion protein shows one way beta sheets can stack. Image originally appeared in a December 2012 PLOS Biology paper.

Microarrays, also called gene chips, are tools that let scientists track the activity of hundreds or thousands of genes simultaneously. For example, researchers can compare the activities of genes in healthy and diseased cells, allowing the scientists to pinpoint which genes and cell processes might be involved in the development of a disease.

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.

Blood vessels at the back of the eye (retina) are used to diagnose glaucoma and diabetic eye disease. They also display characteristic changes in people with high blood pressure. In the image, the vessels appear green. It's not actually the vessels that are stained green, but rather filaments of a protein called actin that wraps around the vessels. Most of the red blood cells were replaced by fluid as the tissue was prepared for the microscope. The tiny red dots are red blood cells that remain in the vessels. The image was captured using confocal and 2-photon excitation microscopy for a project related to neurofibromatosis.

Pigment cells are cells that give skin its color. In fishes and amphibians, like frogs and salamanders, pigment cells are responsible for the characteristic skin patterns that help these organisms to blend into their surroundings or attract mates. The pigment cells are derived from neural crest cells, which are cells originating from the neural tube in the early embryo. Investigating pigment cell formation and migration in animals helps answer important fundamental questions about the factors that control pigmentation in the skin of animals, including humans. This image shows a pigment cell from zebrafish at high resolution. Related to images 5755, 5756, 5757 and 5758.

These smooth muscle cells were derived from mouse neural crest stem cells. Red indicates smooth muscle proteins, blue indicates nuclei. Image and caption information courtesy of the California Institute for Regenerative Medicine.

Each point in these colorful patchworks represents the correlation between two sleep-associated genes in fruit flies. Vibrant reds and oranges represent high and intermediate degrees of association between the genes, respectively. Genes in these areas show similar activity patterns in different fly lines. Cool blues represent gene pairs where one partner's activity is high and the other's is low. The green areas show pairs with activities that are not correlated. These quilt-like depictions help illustrate a recent finding that genes act in teams to influence sleep patterns.

Body organs such as the liver and kidneys process chemicals and toxins. These "target" organs are susceptible to damage caused by these substances. See image 2497 for a labeled version of this illustration.

Microtubules in African green monkey cells. Microtubules are strong, hollow fibers that provide cells with structural support. Here, the microtubules have been color-coded based on their distance from the microscope lens: purple is closest to the lens, and yellow is farthest away. This image was captured using Stochastic Optical Reconstruction Microscopy (STORM).

Related to images 6889, 6890, and 6892.

Mycobacterium tuberculosis, the bacterium that causes tuberculosis, has infected one-quarter of the world's population and causes more than one million deaths each year, according to the World Health Organization.

During DNA replication, each strand of the original molecule acts as a template for the synthesis of a new, complementary DNA strand. See image 2544 for a labeled version of this illustration.

Multicellular yeast called snowflake yeast that researchers created through many generations of directed evolution from unicellular yeast. Cells are connected to one another by their cell walls, shown in blue. Stained cytoplasm (green) and membranes (magenta) show that the individual cells remain separate. This image was captured using spinning disk confocal microscopy.

Related to images 6969 and 6971.

Two fruit fly (Drosophila melanogaster) larvae brains with neurons expressing fluorescently tagged tubulin protein. Tubulin makes up strong, hollow fibers called microtubules that play important roles in neuron growth and migration during brain development. This image was captured using confocal microscopy, and the color indicates the position of the neurons within the brain.

Staphylococcus aureus bacteria (green) grouping together upon contact with synovial fluid—a viscous substance found in joints. The formation of groups can help protect the bacteria from immune system defenses and from antibiotics, increasing the likelihood of an infection. This video is a 1-hour time lapse and was captured using a confocal laser scanning microscope.

More information about the research that produced this video can be found in the Journal of Bacteriology paper "In Vitro Staphylococcal Aggregate Morphology and Protection from Antibiotics Are Dependent on Distinct Mechanisms Arising from Postsurgical Joint Components and Fluid Motion" by Staats et al.

Related to images 6803 and 6804.

Many disease-causing microbes manipulate their host’s metabolism and cells for their own ends. Microsporidia—which are parasites closely related to fungi—infect and multiply inside animal cells, and take the rearranging of cells’ interiors to a new level. They reprogram animal cells such that the cells start to fuse, causing them to form long, continuous tubes. As shown in this image of the roundworm Caenorhabditis elegans, microsporidia (shown in red) have invaded the worm’s gut cells (the large blue dots are the cells' nuclei) and have instructed the cells to merge. The cell fusion enables the microsporidia to thrive and propagate in the expanded space. Scientists study microsporidia in worms to gain more insight into how these parasites manipulate their host cells. This knowledge might help researchers devise strategies to prevent or treat infections with microsporidia.

For more on the research into microsporidia, see this news release from the University of California San Diego. Related to images 5777 and 5778.

Neurons (green) and glial cells from isolated dorsal root ganglia express COX-2 (red) after exposure to an inflammatory stimulus (cell nuclei are blue). Lawrence Marnett and colleagues have demonstrated that certain drugs selectively block COX-2 metabolism of endocannabinoids -- naturally occurring analgesic molecules -- in stimulated dorsal root ganglia. Featured in the October 20, 2011 issue of Biomedical Beat.

This skyline of New York City was created by “printing” nanodroplets containing yeast (Saccharomyces cerevisiae) onto a large plate. Each dot is a separate yeast colony. As the colonies grew, a picture emerged, creating art. To make the different colors shown here, yeast strains were genetically engineered to produce pigments naturally made by bacteria, fungi, and sea creatures such as coral and sea anemones. Using genes from other organisms to make biological compounds paves the way toward harnessing yeast in the production of other useful molecules, from food to fuels and drugs.