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.

Planarians are freshwater flatworms that have powerful abilities to regenerate their bodies, which would seem to make them natural model organisms in which to study stem cells. But until recently, scientists had not been able to efficiently find the genes that regulate the planarian stem cell system. In this image, a single stem cell has given rise to a colony of stem cells in a planarian. Proliferating cells are red, and differentiating cells are blue. Quantitatively measuring the size and ratios of these two cell types provides a powerful framework for studying the roles of stem cell regulatory genes in planarians.

This normal human skin cell was treated with a growth factor that triggered the formation of specialized protein structures that enable the cell to move. We depend on cell movement for such basic functions as wound healing and launching an immune response.

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

Industrious V. cholerae bacteria (yellow) tend to thrive in denser biofilms (left) while moochers (red) thrive in weaker biofilms (right). More information about the research behind this image can be found in a Biomedical Beat Blog posting from February 2014.

This fluorescent microscope image shows human embryonic stem cells whose nuclei are stained green. Blue staining shows the surrounding supportive feeder cells. Image and caption information courtesy of the California Institute for Regenerative Medicine. See related image 3275.

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.

Featured in the March 15, 2012 issue of Biomedical Beat. Related to Hsp33 Figure 1, image 3354.

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.

Sensory organs have cells equipped for detecting signals from the environment, such as odors. Receptors in the membranes of nerve cells in the nose bind to odor molecules, triggering a cascade of chemical reactions tranferred by G proteins into the cytoplasm.

The human skin cells pictured contain genetic modifications that make them pluripotent, essentially equivalent to embryonic stem cells. A scientific team from the University of Wisconsin-Madison including researchers Junying Yu, James Thomson, and their colleagues produced the transformation by introducing a set of four genes into human fibroblasts, skin cells that are easy to obtain and grow in culture.

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.

These time series show the heart rates of four different individuals. Automakers use steel scraps to build cars, construction companies repurpose tires to lay running tracks, and now scientists are reusing previously discarded medical data to better understand our complex physiology. Through a website called PhysioNet developed in part by Beth Israel Deaconess Medical Center cardiologist Ary Goldberger, scientists can access complete physiologic recordings, such as heart rate, respiration, brain activity and gait. They then can use free software to analyze the data and find patterns in it. The patterns could ultimately help health care professionals diagnose and treat health conditions like congestive heart failure, sleeping disorders, epilepsy and walking problems. PhysioNet is supported by NIH's National Institute of Biomedical Imaging and Bioengineering as well as by NIGMS.

This illustration highlights spherical pre-synaptic vesicles that carry the neurotransmitter glutamate. The presynaptic and postsynaptic membranes are shown with proteins relevant for transmitting and modulating the neuronal signal.

PDB 101’s Opioids and Pain Signaling video explains how glutamatergic synapses are involved in the process of pain signaling.

Cell mopping up.

Genes are often interrupted by stretches of DNA (introns, blue) that do not contain instructions for making a protein. The DNA segments that do contain protein-making instructions are known as exons (green). See image 2551 for a labeled version of this illustration. Featured in The New Genetics.

The receptor is shown bound to a small molecule peptide called CVX15.

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.

Model of the enzyme aminopeptidase N from the human pathogen Neisseria meningitidis, which can cause meningitis epidemics. The structure provides insight on the active site of this important molecule.

In the worm C. elegans, double-stranded RNA made in neurons can silence matching genes in a variety of cell types through the transport of RNA between cells. The head region of three worms that were genetically modified to express a fluorescent protein were imaged and the images were color-coded based on depth. The worm on the left lacks neuronal double-stranded RNA and thus every cell is fluorescent. In the middle worm, the expression of the fluorescent protein is silenced by neuronal double-stranded RNA and thus most cells are not fluorescent. The worm on the right lacks an enzyme that amplifies RNA for silencing. Surprisingly, the identities of the cells that depend on this enzyme for gene silencing are unpredictable. As a result, worms of identical genotype are nevertheless random mosaics for how the function of gene silencing is carried out. For more, see journal article and press release. Related to image 6534.

Like a strand of white pearls, DNA wraps around an assembly of special proteins called histones (colored) to form the nucleosome, a structure responsible for regulating genes and condensing DNA strands to fit into the cell's nucleus. Researchers once thought that nucleosomes regulated gene activity through their histone tails (dotted lines), but a 2010 study revealed that the structures' core also plays a role. The finding sheds light on how gene expression is regulated and how abnormal gene regulation can lead to cancer.

The nucleolus is a small but very important protein complex located in the cell's nucleus. It forms on the chromosomes at the location where the genes for the RNAs are that make up the structure of the ribosome, the indispensable cellular machine that makes proteins from messenger RNAs.

However, how the nucleolus grows and maintains its structure has puzzled scientists for some time. It turns out that even though it looks like a simple liquid blob, it's rather well-organized, consisting of three distinct layers: the fibrillar center, where the RNA polymerase is active; the dense fibrillar component, which is enriched in the protein fibrillarin; and the granular component, which contains a protein called nucleophosmin. Researchers have now discovered that this multilayer structure of the nucleolus arises from difference in how the proteins in each compartment mix with water and with each other. These differences let them readily separate from each other into the three nucleolus compartments.

This video of nucleoli in the eggs of a commonly used lab animal, the frog Xenopus laevis, shows how each of the compartments (the granular component is shown in red, the fibrillarin in yellow-green, and the fibrillar center in blue) spontaneously fuse with each other on encounter without mixing with the other compartments. For more details on this research, see this press release from Princeton. Related to video 3791, image 3792 and image 3793.

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.

Yeast cells with endocytic actin patches (green). These patches help cells take in outside material. When a cell is in interphase, patches concentrate at its ends. During later stages of cell division, patches move to where the cell splits. This image was captured using wide-field microscopy with deconvolution.

Related to images 6791, 6792, 6794, 6797, 6798, and videos 6795 and 6796.

Xenopus laevis, the African clawed frog, has long been used as a research organism for studying embryonic development. The abnormal presence of RNA encoding the signaling molecule plakoglobin causes atypical signaling, giving rise to a two-headed tadpole.

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.

The white circle in this image is a Petri dish, named for its inventor, Julius Richard Petri. These dishes are one of the most common pieces of equipment in biology labs, where researchers use them to grow cells.

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

Crystal structure of oligoendopeptidase F, a protein slicing enzyme from Bacillus stearothermophilus, a bacterium that can cause food products to spoil. The crystal was formed using a microfluidic capillary, a device that enables scientists to independently control the parameters for protein crystal nucleation and growth. Featured as one of the July 2007 Protein Structure Initiative Structures of the Month.

A light organ (~0.5 mm across) of a Hawaiian bobtail squid, Euprymna scolopes, with different tissues are stained various colors. The two pairs of ciliated appendages, or “arms,” on the sides of the organ move Vibrio fischeri bacterial cells closer to the two sets of three pores (two seen in this image) at the base of the arms that each lead to an interior crypt. This image was taken using a confocal fluorescence microscope.

Related to images 7016, 7018, 7019, and 7020.

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.

Yeast cells with nuclear envelopes shown in magenta and tubulin shown in light blue. The nuclear envelope defines the borders of the nucleus, which houses DNA. Tubulin is a protein that makes up microtubules—strong, hollow fibers that provide structure to cells and help direct chromosomes during cell division. This image was captured using wide-field microscopy with deconvolution.

Related to images 6791, 6792, 6793, 6794, 6797, and videos 6795 and 6796.

Model of an enzyme, PanC, that is involved in the last step of vitamin B5 biosynthesis in Mycobacterium tuberculosis. PanC is essential for the growth of M. tuberculosis, which causes most cases of tuberculosis, and is therefore a potential drug target.

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

In the determination of protein structures by X-ray crystallography, this unique soft (l = 2.29Å) X-ray source is used to collect anomalous scattering data from protein crystals containing light atoms such as sulfur, calcium, zinc and phosphorous. These data can be used to image the protein.

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

The world's smallest motor, ATP synthase, generates energy for the cell. See image 2518 for a labeled version of this illustration. Featured in The Chemistry of Health.

To become products, reactants must overcome an energy hill. See image 2526 for a labeled version of this illustration. Featured in The Chemistry of Health.

This is a super-resolution light microscope image taken by Hiro Hakozaki and Masa Hoshijima of NCMIR. The image contains highlighted calcium channels in cardiac muscle using a technique called dSTORM. The microscope used in the NCMIR lab was built by Hiro Hakozaki.

The long, stringy DNA that makes up genes is spooled within chromosomes inside the nucleus of a cell. (Note that a gene would actually be a much longer stretch of DNA than what is shown here.) See image 2539 for an unlabeled version of this illustration. Featured in The New Genetics.

New research shows telomeres moving to the outer edge of the nucleus after cell division, suggesting these caps that protect chromosomes also may play a role in organizing DNA.

Protein kinases—enzymes that add phosphate groups to molecules—are cancer chemotherapy targets because they play significant roles in almost all aspects of cell function, are tightly regulated, and contribute to the development of cancer and other diseases if any alterations to their regulation occur. Genetic abnormalities affecting the c-Abl tyrosine kinase are linked to chronic myelogenous leukemia, a cancer of immature cells in the bone marrow. In the noncancerous form of the protein, binding of a myristoyl group to the kinase domain inhibits the activity of the protein until it is needed (top left shows the inactive form, top right shows the open and active form). The cancerous variant of the protein, called Bcr-Abl, lacks this autoinhibitory myristoyl group and is continually active (bottom). ATP is shown in green bound in the active site of the kinase.

Find these in the RCSB Protein Data Bank: c-Abl tyrosine kinase and regulatory domains (PDB entry 1OPL) and F-actin binding domain (PDB entry 1ZZP).

Cells walk along body surfaces via tiny "feet," called focal adhesions, that connect with the extracellular matrix. See image 2503 for a labeled version of this illustration.

Fruit fly (Drosophila melanogaster) ovaries with DNA shown in magenta and actin filaments shown in light blue. This image was captured using a confocal laser scanning microscope.

Related to image 6806.

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 are super-resolution microscopic images of the peripheral ER showing the structure of an ER tubular matrix between the plasma membranes of the cell. See image 5857 for a more detailed view of the area outlined in white in this image. For another view of the ER tubular matrix see image 5855

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.

Stained kidney tissue. The kidney is an essential organ responsible for disposing wastes from the body and for maintaining healthy ion levels in the blood. It also secretes two hormones, erythropoietin (EPO) and calcitriol (a derivative of vitamin D), into the blood. It works like a purifier by pulling break-down products of metabolism, such as urea and ammonium, from the blood stream for excretion in urine. Related to image 3725.

The illustration shows the capsid of human immunodeficiency virus (HIV) whose molecular features were resolved with cryo-electron microscopy (cryo-EM). On the left, the HIV capsid is "naked," a state in which it would be easily detected by and removed from cells. However, as shown on the right, when the viral capsid binds to and is covered with a host protein, called cyclophilin A (shown in red), it evades detection and enters and invades the human cell to use it to establish an infection. To learn more about how cyclophilin A helps HIV infect cells and how scientists used cryo-EM to find out the mechanism by which the HIV capsid attaches to cyclophilin A, see this news release by the University of Illinois. A study reporting these findings was published in the journal Nature Communications.

Stereo triplet of a sea urchin embryo stained to reveal actin filaments (orange) and microtubules (blue). This image is part of a series of images: 1047, 1048, 1050, 1051 and 1052.

A team of chemists and physicists used nanotechnology and DNA's ability to self-assemble with matching RNA to create a new kind of chip for measuring gene activity. When RNA of a gene of interest binds to a DNA tile (gold squares), it creates a raised surface (white areas) that can be detected by a powerful microscope. This nanochip approach offers manufacturing and usage advantages over existing gene chips and is a key step toward detecting gene activity in a single cell. Featured in the February 20, 2008, issue of Biomedical Beat.

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 3437.