Genome editing using CRISPR/Cas9 is a rapidly expanding field of scientific research with emerging applications in disease treatment, medical therapeutics and bioenergy, just to name a few. This technology is now being used in laboratories all over the world to enhance our understanding of how living biological systems work, how to improve treatments for genetic diseases and how to develop energy solutions for a better future.

Duplicated pair of chromosomes lined up and ready to cross over.

A cell in anaphase during mitosis: Chromosomes separate into two genetically identical groups and move to opposite ends of the spindle. Mitosis is responsible for growth and development, as well as for replacing injured or worn out cells throughout the body. For simplicity, mitosis is illustrated here with only six chromosomes.

Ribosomes are complex machines made up of more than 50 proteins and three or four strands of genetic material called ribosomal RNA (rRNA). The busy cellular machines make proteins, which are critical to almost every structure and function in the cell. To do so, they read protein-building instructions, which come as strands of messenger RNA. Ribosomes are found in all forms of cellular life—people, plants, animals, even bacteria. This illustration of a bacterial ribosome was produced using detailed information about the position of every atom in the complex. Several antibiotic medicines work by disrupting bacterial ribosomes but leaving human ribosomes alone. Scientists are carefully comparing human and bacterial ribosomes to spot differences between the two. Structures that are present only in the bacterial version could serve as targets for new antibiotic medications.

A computer model of the cell membrane, where the plasma membrane is red, endoplasmic reticulum is yellow, and mitochondria are blue. This image relates to a July 27, 2009 article in Computing Life.

A blue laser beam turns on a protein that helps this human cancer cell move. Responding to the stimulus, the protein, called Rac1, first creates ruffles at the edge of the cell. Then it stretches the cell forward, following the light like a horse trotting after a carrot on a stick. This new light-based approach can turn Rac1 (and potentially many other proteins) on and off at exact times and places in living cells. By manipulating a protein that controls movement, the technique also offers a new tool to study embryonic development, nerve regeneration and cancer.

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.

Time lapse series shows short dynamin assemblies (not visible) constricting a lipid tube to make a "beads on a string" appearance, then cutting off one of the beads i.e., catalyzing membrane fission). The lipids are fluorescent (artificially colored). Ramachandran R, Pucadyil T.J., Liu Y.W., Acharya S., Leonard M., Lukiyanchuk V., Schmid S.L. 2009. Membrane insertion of the pleckstrin homology domain variable loop 1 is critical for dynamin-catalyzed vesicle scission. Mol Biol Cell. 2009 20:4630-9.

CCD-1 is an enzyme produced by the bacterium Clostridioides difficile that helps it resist antibiotics. Using X-ray crystallography, researchers determined the structure of a CCD-1 molecule and a molecule of the antibiotic cefotaxime bound together. The structure revealed that CCD-1 provides extensive hydrogen bonding and stabilization of the antibiotic in the active site, leading to efficient degradation of the antibiotic.

Related to images 6764, 6765, and 6767.

Histone proteins loop together with double-stranded DNA to form a structure that resembles beads on a string. See image 2561 for a labeled version of this illustration. Featured in The New Genetics.

When the heat shock protein hsp33 is folded, it is inactive and contains a zinc ion, stabilizing the redox sensitive domain (orange). In the presence of an environmental stressor, the protein releases the zinc ion, which leads to the unfolding of the redox domain. This unfolding causes the chaperone to activate by reaching out its "arm" (green) to protect other proteins.

Molecular model of the struture of heme. Heme is a small, flat molecule with an iron ion (dark red) at its center. Heme is an essential component of hemoglobin, the protein in blood that carries oxygen throughout our bodies. This image first appeared in the September 2013 issue of Findings Magazine. View side view of heme here 3539.

These images model the molecular structures of three enzymes with critical roles in the life cycle of the human immunodeficiency virus (HIV). At the top, reverse transcriptase (orange) creates a DNA copy (yellow) of the virus's RNA genome (blue). In the middle image, integrase (magenta) inserts this DNA copy in the DNA genome (green) of the infected cell. At the bottom, much later in the viral life cycle, protease (turquoise) chops up a chain of HIV structural protein (purple) to generate the building blocks for making new viruses. See these enzymes in action on PDB 101’s video A Molecular View of HIV Therapy.

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.

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.

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.

An adult female Hawaiian bobtail squid, Euprymna scolopes, with its mantle cavity exposed from the underside. Some internal organs are visible, including the two lobes of the light organ that contains bioluminescent bacteria, Vibrio fischeri. The light organ includes accessory tissues like an ink sac (black) that serves as a shutter, and a silvery reflector that directs the light out of the underside of the animal.

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.

This illustration represents the early life of a protein—specifically, apomyoglobin—as it is synthesized by a ribosome and emerges from the ribosomal tunnel, which contains the newly formed protein's conformation. The synthesis occurs in the complex swirl of the cell medium, filled with interactions among many molecules. Researchers in Silvia Cavagnero's laboratory are studying the structure and dynamics of newly made proteins and polypeptides using spectroscopic and biochemical techniques.

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

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 2006, scientists developed an optical microscopy technique enabling them to clearly see individual molecules within cells. In 2007, they took the technique, abbreviated STORM, a step further. They identified multicolored probes that let them peer into cells and clearly see multiple cellular components at the same time, such as these microtubules (green) and small hollows called clathrin-coated pits (red). Unlike conventional methods, the multicolor STORM technique produces a crisp and high resolution picture. A sharper view of how cellular components interact will likely help scientists answer some longstanding questions about cell biology.

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.

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.

Yeast cells with nuclei shown in green and contractile rings shown in magenta. Nuclei store DNA, and contractile rings help cells divide. This image was captured using wide-field microscopy with deconvolution.

Related to images 6791, 6793, 6794, 6797, 6798, and videos 6795 and 6796.

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.

Insect brains, like the honeybee brain shown here, are very different in shape from human brains. Despite that, bee and human brains have a lot in common, including many of the genes and neurochemicals they rely on in order to function. The bright-green spots in this image indicate the presence of tyrosine hydroxylase, an enzyme that allows the brain to produce dopamine. Dopamine is involved in many important functions, such as the ability to experience pleasure. This image was captured using confocal microscopy.

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.

Originally from the waters of India, Nepal, and neighboring countries, zebrafish can now be found swimming in science labs (and home aquariums) throughout the world. This fish is a favorite study subject for scientists interested in how genes guide the early stages of prenatal development (including the developing fin shown here) and in the effects of environmental contamination on embryos.

In this image, green fluorescent protein (GFP) is expressed where the gene sox9b is expressed. Collagen (red) marks the fin rays, and DNA, stained with a dye called DAPI, is in blue. sox9b plays many important roles during development, including the building of the heart and brain, and is also necessary for skeletal development. At the University of Wisconsin, researchers have found that exposure to contaminants that bind the aryl-hydrocarbon receptor results in the downregulation of sox9b. Loss of sox9b severely disrupts development in zebrafish and causes a life-threatening disorder called campomelic dysplasia (CD) in humans. CD is characterized by cardiovascular, neural, and skeletal defects. By studying the roles of genes such as sox9b in zebrafish, scientists hope to better understand normal development in humans as well as how to treat developmental disorders and diseases.

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

These neurons are derived from mouse embryonic stem cells. Red shows cells making a protein called TH that is characteristic of the neurons that degenerate in Parkinson's disease. Green indicates a protein that's found in all neurons. Blue indicates the nuclei of all cells. Studying dopaminergic neurons can help researchers understand the origins of Parkinson's disease and could be used to screen potential new drugs. Image and caption information courtesy of the California Institute for Regenerative Medicine. Related to images 3270 and 3285.

A typical animal cell, sliced open to reveal a cross-section of organelles.

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.

Multiple actin filaments (magenta) are organized around a dynamin helical polymer (rainbow colored) in this model derived from cryo-electron tomography. By bundling actin, dynamin increases the strength of a cell’s skeleton and plays a role in cell-cell fusion, a process involved in conception, development, and regeneration.

From PDB entry 3c6k, Crystal structure of human spermine synthase in complex with spermidine and 5-methylthioadenosine.

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.

These colorful, computer-generated ribbons show the backbone of a molecule that glows a fluorescent red. The molecule, called mStrawberry, was created by chemists based on a protein found in the ruddy lips of a coral. Scientists use the synthetic molecule and other "fruity" ones like it as a dye to mark and study cell structures.

Researchers doing behavioral experiments with honeybees sometimes use paint or enamel to give individual bees distinguishing marks. The elaborate social structure and impressive learning and navigation abilities of bees make them good models for behavioral and neurobiological research. Since the sequencing of the honeybee genome, published in 2006, bees have been used increasingly for research into the molecular basis for social interaction and other complex behaviors.

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.

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.

These images show three stages of cell division in Xenopus XL177 cells, which are derived from tadpole epithelial cells. They are (from top): metaphase, anaphase and telophase. The microtubules are green and the chromosomes are blue. Related to 3443.

Cryo-electron microscopy (cryo-EM) has the power to capture details of proteins and other small biological structures at the molecular level.  This image shows proteins in the capsid, or outer cover, of bacteriophage P22, a virus that infects the Salmonella bacteria. Each color shows the structure and position of an individual protein in the capsid. Thousands of cryo-EM scans capture the structure and shape of all the individual proteins in the capsid and their position relative to other proteins. A computer model combines these scans into the three-dimension image shown here. Related to image 5875.

Leptospira, shown here in green, is a type (genus) of elongated, spiral-shaped bacteria. Infection can cause Weil's disease, a kind of jaundice, in humans.

Haplotypes are combinations of gene variants that are likely to be inherited together within the same chromosomal region. In this example, an original haplotype (top) evolved over time to create three newer haplotypes that each differ by a few nucleotides (red). See image 2567 for a labeled version of this illustration. Featured in The New Genetics.

CCD-1 is an enzyme produced by the bacterium Clostridioides difficile that helps it resist antibiotics. Here, researchers crystallized bound pairs of CCD-1 molecules and molecules of the antibiotic cefotaxime. This enabled their structure to be studied using X-ray crystallography.

Related to images 6765, 6766, and 6767.

In plants, as in animals, stem cells can transform into a variety of different cell types. The stem cells at the growing tip of this Arabidopsis plant will soon become flowers. Arabidopsis is frequently studied by cellular and molecular biologists because it grows rapidly (its entire life cycle is only 6 weeks), produces lots of seeds, and has a genome that is easy to manipulate.

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

The incredible complexity of a mammalian eye (in this case from a mouse) is captured here. Each color represents a different type of cell. In total, there are nearly 70 different cell types, including the retina's many rings and the peach-colored muscle cells clustered on the left.

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

Animation for the cisternae maturation model of Golgi transport.

This 1 1/2-minute video animation was produced for chemical biologist Stuart Schreiber's lab page. The animation shows how diverse chemical structures can be produced in the lab.

Los ritmos circadianos son cambios físicos, mentales y de comportamiento que siguen un ciclo de 24 horas. Los ritmos circadianos se ven influenciados por la luz y están regulados por el núcleo supraquiasmático del cerebro, a veces denominado el reloj principal.

Vea 6613 para la versión en inglés de esta infografía.

This network map shows molecular interactions (yellow) associated with a congenital condition that causes heart arrhythmias and the targets for drugs that alter these interactions (red and blue).