Atomic model of the membrane region of the mitochondrial ATP synthase built into a cryo-EM map at 3.6 Å resolution. ATP synthase is the primary producer of ATP in aerobic cells. Drugs that inhibit the bacterial ATP synthase, but not the human mitochondrial enzyme, can serve as antibiotics. This therapeutic approach was successfully demonstrated with the bedaquiline, an ATP synthase inhibitor now used in the treatment of extensively drug resistant tuberculosis.

More information about this structure can be found in the Science paper ”Atomic model for the dimeric F0 region of mitochondrial ATP synthase” by Guo et. al.

The Golgi complex, also called the Golgi apparatus or, simply, the Golgi. This organelle receives newly made proteins and lipids from the ER, puts the finishing touches on them, addresses them, and sends them to their final destinations.

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 3607.

Confocal image showing high levels of the protein vimentin (white) at the edge zone of a quail embryo. Cell nuclei are labeled green. More specifically, this high-magnification (60X) image shows vimentin immunofluorescence in the edge zone (top of image) and inner zone (bottom of image) of a Stage 4 quail blastoderm. Vimentin expression (white) is shown merged with Sytox nuclear labeling (green) at the edge of the blastoderm. A thick vimentin filament runs circumferentially (parallel to the direction of the edge) that appears to delineate the transition between the edge zone and interior zone. Also shown are dense vimentin clusters or foci, which typically appear to be closely associated with edge cell nuclei. An NIGMS grant to Professor Garcia was used to purchase the confocal microscope that collected this image. Related to image 2808 and video 2809.

Borrelia burgdorferi is a spirochete, a class of long, slender bacteria that typically take on a coiled shape. Infection with this bacterium causes Lyme disease.

The proteasome is a critical multiprotein complex in the cell that breaks down and recycles proteins that have become damaged or are no longer needed. This movie shows how a protein substrate (red) is bound through its ubiquitin chain (blue) to one of the ubiquitin receptors of the proteasome (Rpn10, yellow). The substrate's flexible engagement region then gets engaged by the AAA+ motor of the proteasome (cyan), which initiates mechanical pulling, unfolding and movement of the protein into the proteasome's interior for cleavage into shorter protein pieces called peptides. During movement of the substrate, its ubiquitin modification gets cleaved off by the deubiquitinase Rpn11 (green), which sits directly above the entrance to the AAA+ motor pore and acts as a gatekeeper to ensure efficient ubiquitin removal, a prerequisite for fast protein breakdown by the 26S proteasome. Related to image 3763.

Neutrophil-like cells (blue) in a microfluidic chip preferentially migrating toward LTB4 over fMLP. A neutrophil is a type of white blood cell that is part of the immune system and helps the body fight infection. Both LTB4 and fMLP are molecules involved in immune response. Microfluidic chips are small devices containing microscopic channels, and they are used in a range of applications, from basic research on cells to pathogen detection. The scale bar in this video is 500μm.

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

These images illustrate a technique combining cryo-electron tomography and super-resolution fluorescence microscopy called correlative imaging by annotation with single molecules (CIASM). CIASM enables researchers to identify small structures and individual molecules in cells that they couldn’t using older techniques.

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, 1049, 1050 and 1052.

Here, a human HeLa cell (a type of immortal cell line used in laboratory experiments) is undergoing cell division. They come from cervical cancer cells that were obtained in 1951 from Henrietta Lacks, a patient at the Johns Hopkins Hospital. The final stage of division, called cytokinesis, occurs after the genomes—shown in yellow—have split into two new daughter cells. The myosin II is a motor protein shown in blue, and the actin filaments, which are types of protein that support cell structure, are shown in red.

This image shows the uncontrolled growth of cells in squamous cell carcinoma, the second most common form of skin cancer. If caught early, squamous cell carcinoma is usually not life-threatening.

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

The structure of the pore-forming protein VDAC-1 from humans. This molecule mediates the flow of products needed for metabolism--in particular the export of ATP--across the outer membrane of mitochondria, the power plants for eukaryotic cells. VDAC-1 is involved in metabolism and the self-destruction of cells--two biological processes central to health.

Related to images 2491, 2494, and 2495.

A growing Vibrio cholerae (cholera) biofilm. Cholera bacteria form colonies called biofilms that enable them to resist antibiotic therapy within the body and other challenges to their growth.

Each slightly curved comma shape represents an individual bacterium from assembled confocal microscopy images. Different colors show each bacterium’s position in the biofilm in relation to the surface on which the film is growing.

A shell from the venomous cone snail Conus omaria, which lives in the Pacific and Indian oceans and eats other snails. University of Utah scientists discovered a new toxin in this snail species' venom, and say it will be a useful tool in designing new medicines for a variety of brain disorders, including Alzheimer's and Parkinson's diseases, depression, nicotine addiction and perhaps schizophrenia.

The green in this image highlights a protein called TonB, which is produced by many gram-negative bacteria, including those that cause typhoid fever, meningitis and dysentery. TonB lets bacteria take up iron from the host's body, which they need to survive. More information about the research behind this image can be found in a Biomedical Beat Blog posting from August 2013.

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, a multivesicular body (the round structure slightly to the right of center) contain tiny intralumenal vesicles (with a diameter of only 25 nanometers; the round specks inside the larger round structure) adjacent to the cell's vacuole (below the multivesicular body, shown in darker and more uniform gray).

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 color-enhanced version 5767 and image 5769.

Two healthy cells (bottom, left) enter into apoptosis (bottom, center) but spring back to life after a fatal toxin is removed (bottom, right; top).

To become products, reactants must overcome an energy hill. See image 2525 for an unlabeled version of this illustration. Featured in The Chemistry of Health.

This image of the hippocampus was taken with an ultra-widefield high-speed multiphoton laser microscope. Tissue was stained to reveal the organization of glial cells (cyan), neurofilaments (green) and DNA (yellow). The microscope Deerinck used was developed in conjunction with Roger Tsien (2008 Nobel laureate in Chemistry) and remains a powerful and unique tool today.

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.

Mouse embryonic stem cells matured into this bundle of hair cells similar to the ones that transmit sound in the ear. These cells could one day be transplanted as a therapy for some forms of deafness, or they could be used to screen drugs to treat deafness. The hairs are shown at 23,000 times magnification via scanning electron microscopy. Image and caption information courtesy of the California Institute for Regenerative Medicine.

Like a group of barnacles hanging onto a rock, these human cells hang onto a matrix coated glass slide. Actin stress fibers, stained magenta, and the protein vinculin, stained green, make this adhesion possible. The fibroblast nuclei are stained blue.

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.

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.

During mitosis, spindle microtubules (red) attach to chromosome pairs (blue), directing them to the spindle equator. This midline alignment is critical for equal distribution of chromosomes in the dividing cell. Scientists are interested in how the protein kinase Plk1 (green) regulates this activity in human cells. Image is a volume projection of multiple deconvolved z-planes acquired with a Nikon widefield fluorescence microscope. This image was chosen as a winner of the 2016 NIH-funded research image call. Related to image 5766.

The research that led to this image was funded by NIGMS.

In many animals, the egg cell develops alongside sister cells. These sister cells are called nurse cells in the fruit fly (Drosophila melanogaster), and their job is to “nurse” an immature egg cell, or oocyte. Toward the end of oocyte development, the nurse cells transfer all their contents into the oocyte in a process called nurse cell dumping. This video captures this transfer, showing significant shape changes on the part of the nurse cells (blue), which are powered by wavelike activity of the protein myosin (red). Researchers created the video using a confocal laser scanning microscope. Related to image 6753.

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 have lined up in the middle of the dividing cell.

Related to images 1010, 1011, 1012, 1013, 1014, 1015, 1016, 1018, 1019, and 1021.

Actin gliding powered by myosin 1D. Note the counterclockwise motion of the gliding actin filaments.

This illustration shows, in simplified terms, how the CRISPR-Cas9 system can be used as a gene-editing tool. This is the first frame in a series of four. The CRISPR system has two components joined together: a finely tuned targeting device (a small strand of RNA programmed to look for a specific DNA sequence) and a strong cutting device (an enzyme called Cas9 that can cut through a double strand of DNA).

For an explanation and overview of the CRISPR-Cas9 system, see the iBiology video, and find the full CRIPSR illustration here.

In SARS-CoV-2, the virus that causes COVID-19, nucleocapsid is a complex molecule with many functional parts. One section folds into an RNA-binding domain, with a groove that grips a short segment of the viral genomic RNA. Another section folds into a dimerization domain that brings two nucleocapsid molecules together. The rest of the protein is intrinsically disordered, forming tails at each end of the protein chain and a flexible linker that connects the two structured domains. These disordered regions assist with RNA binding and orchestrate association of nucleocapsid dimers into larger assemblies that package the RNA in the small space inside virions. Nucleocapsid is in magenta and purple, and short RNA strands are in yellow.

Find these in the RCSB Protein Data Bank: RNA-binding domain (PDB entry 7ACT) and Dimerization domain (PDB entry 6WJI).

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. Image created using confocal microscopy.

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

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

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.

Each of the colored specs in this image is a cell on the surface of a fish scale. To better understand how wounds heal, scientists have inserted genes that make cells brightly glow in different colors into the skin cells of zebrafish, a fish often used in laboratory research. The colors enable the researchers to track each individual cell, for example, as it moves to the location of a cut or scrape over the course of several days. These technicolor fish endowed with glowing skin cells dubbed "skinbow" provide important insight into how tissues recover and regenerate after an injury.

For more information on skinbow fish, see the Biomedical Beat blog post Visualizing Skin Regeneration in Real Time and a press release from Duke University highlighting this research. Related to image 3783.

A macrophage—a type of immune cell that engulfs invaders—“eats” and is activated by a “two-faced” Janus particle. The particle is called “two-faced” because each of its two hemispheres is coated with a different type of molecule, shown here in red and cyan. During macrophage activation, a transcription factor tagged with a green fluorescence protein (NF-κB) gradually moves from the cell’s cytoplasm into its nucleus and causes DNA transcription. The distribution of molecules on “two-faced” Janus particles can be altered to control the activation of immune cells. Details on this “geometric manipulation” strategy can be found in the Proceedings of the National Academy of Sciences paper "Geometrical reorganization of Dectin-1 and TLR2 on single phagosomes alters their synergistic immune signaling" by Li et al. and the Scientific Reports paper "Spatial organization of FcγR and TLR2/1 on phagosome membranes differentially regulates their synergistic and inhibitory receptor crosstalk" by Li et al. This video was captured using epi-fluorescence microscopy.

Related to video 6800.

RNA incorporated into the CRISPR surveillance complex is positioned to scan across foreign DNA. Cryo-EM density from a 3Å reconstruction is shown as a yellow mesh.

A white poppy. View cropped image of a poppy here 3423.

X-ray co-crystal structure of Src kinase bound to a DNA-templated macrocycle inhibitor. Related to 3414, 3415, 3416, 3417, 3418, and 3419.

Student Christina Hueneke of the Midwest Center for Structural Genomics is overseeing a protein cloning robot. The robot was designed as part of an effort to exponentially increase the output of a traditional wet lab. Part of the center's goal is to cut the average cost of analyzing a protein from $200,000 to $20,000 and to slash the average time from months to days and hours.

Two cells over a 2-hour period. The one on the bottom left goes through programmed cell death, also known as apoptosis. The one on the top right goes through cell division, also called mitosis. This video was captured using a confocal microscope.

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.

Serum albumin (SA) is the most abundant protein in the blood plasma of mammals. SA has a characteristic heart-shape structure and is a highly versatile protein. It helps maintain normal water levels in our tissues and carries almost half of all calcium ions in human blood. SA also transports some hormones, nutrients and metals throughout the bloodstream. Despite being very similar to our own SA, those from other animals can cause some mild allergies in people. Therefore, some scientists study SAs from humans and other mammals to learn more about what subtle structural or other differences cause immune responses in the body.

Related to entries 3744 and 3746

This illustration of an epoxide-opening cascade promoted by water emulates the proposed biosynthesis of some of the Red Tide toxins.

This video shows the structure of the pore-forming protein VDAC-1 from humans. This molecule mediates the flow of products needed for metabolism--in particular the export of ATP--across the outer membrane of mitochondria, the power plants for eukaryotic cells. VDAC-1 is involved in metabolism and the self-destruction of cells--two biological processes central to health.

Related to videos 2571 and 2572.

Moving protein or other molecules to specific cells to treat or examine them has been a major biological challenge. Scientists have now developed a technique for delivering chemicals to individual cells. The approach involves gold nanowires that, for example, can carry tumor-killing proteins. The advance was possible after researchers developed electric tweezers that could manipulate gold nanowires to help deliver drugs to single cells.

This movie shows the manipulation of the nanowires for drug delivery to a single cell. To learn more about this technique, see this post in the Computing Life series.

If a picture is worth a thousand words, what's a movie worth? For researchers studying cell migration, a "documentary" of fruit fly cells (bright green) traversing an egg chamber could answer longstanding questions about cell movement. Historically, researchers have been unable to watch this cell migration unfold in living ovarian tissue in real time. But by developing a culture medium that allows fly eggs to survive outside their ovarian homes, scientists can observe the nuances of cell migration as it happens. Such details may shed light on how immune cells move to a wound and why cancer cells spread to other sites. See 3594 for still image.

Meiosis is used to make sperm and egg cells. During meiosis, a cell's chromosomes are copied once, but the cell divides twice. During mitosis, the chromosomes are copied once, and the cell divides once. For simplicity, cells are illustrated with only three pairs of chromosomes. See image 6788 for a labeled version of this illustration.

The cerebellum is the brain's locomotion control center. Found at the base of your brain, the cerebellum is a single layer of tissue with deep folds like an accordion. People with damage to this region of the brain often have difficulty with balance, coordination and fine motor skills.

This image of a mouse cerebellum is part of a collection of such images in different colors and at different levels of magnification from the National Center for Microscopy and Imaging Research (NCMIR). Related to image 5800.