Cool Images: A Holiday-Themed Collection

Here are some images from our gallery that remind us of the winter holidays—and showcase important findings and innovations in biomedical research.

Ribbons and Wreaths
This wreath represents the molecular structure of a protein, Cas4, which is part of a system, known as CRISPR, that bacteria use to protect themselves against viral invaders. The green ribbons show the protein’s structure, and the red balls show the location of iron and sulfur molecules important for the protein’s function. Scientists have harnessed Cas9, a different protein in the bacterial CRISPR system, to create a gene-editing tool known as CRISPR-Cas9. Using this tool, researchers can study a range of cellular processes and human diseases more easily, cheaply and precisely. Last week, Science magazine recognized the CRISPR-Cas9 gene-editing tool as the “breakthrough of the year.”

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Cracking a Ubiquitous Code

We asked the heads of our scientific divisions to tell us about some of the big questions in fundamental biomedical science that researchers are investigating with NIGMS support. This article is the third in an occasional series that explores these questions and explains how pursuing the answers could advance understanding of important biological processes.

Ubiquitin (Ub) molecules
Ubiquitin (Ub) molecules attached to proteins can form possibly hundreds of different shapes. Credit: NIGMS.

Researchers are on a quest to crack a code made by ubiquitin, a small protein that plays a big role in coordinating cellular function. By attaching to other proteins, ubiquitin determines what those proteins should do next.

Just as zip codes direct letters to specific towns, the ubiquitin code might direct one protein to help with DNA repair, another to assist in cell division, and a third to transport molecules into and out of cells. Continue reading

Cool Image: Tracing Proteins in Action

Bright amorphous loops

These bright, amorphous loops represent a never-before-seen glimpse at how proteins that play a key role in cell duplication are themselves duplicated. Credit: Sue Jaspersen, Zulin Yu and Jay Unruh, Stowers Institute for Medical Research.

Looking like necklaces stacked on a dresser, these bright, amorphous loops show the outlines of yeast proteins that make up the spindle pole, a cellular component found in organisms as diverse as yeast and humans. Each cell starts with a single spindle pole, which must somehow duplicate to form the pair that works together to pull matching chromosomes apart during cell division. Scientists don’t completely understand how this duplication occurs, but they do know that errors in spindle pole copying can lead to a number of health conditions, including cancer. Continue reading

Cool Images: A Halloween-Inspired Cell Collection

As Halloween approaches, we turned up some spectral images from our gallery. The collection below highlights some spooky-sounding—but really important—biological topics that researchers are actively investigating to spur advances in medicine.

Cell Skeleton
Fibroblast
The cell skeleton, or cytoskeleton, is the framework that gives a cell its shape, helps it move and keeps its contents organized for proper function. A cell that lacks a cytoskeleton becomes misshapen and immobile. This fibroblast, a cell that normally makes connective tissues and travels to the site of a wound to help it heal, is lacking a cytoskeleton. Researchers have associated faulty cytoskeletons and resulting abnormal cell movement with birth defects and weakened immune system functioning. See a fibroblast with a healthy skeleton.

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Help Spread the Word About Cell Day

Editor’s Note: This post originally appeared on our Feedback Loop blog. We’re sharing it here because we think you or others you know may be interested in participating in this science education event.

Cell Day 2015On November 5, we’ll host my favorite NIGMS science education event: Cell Day! As in previous years, we hope this free, interactive Web chat geared for middle and high school students will spark interest in cell biology, biochemistry and research careers. Please help us spread the word by letting people in your local schools and communities know about this special event and encouraging them to register. It runs from 10 a.m. to 3 p.m. EST and is open to all.

As the moderator of these Cell Day chats, I’ve fielded a lot of great questions, including “Why are centrioles not found in plant cells?” and “If you cut a cell in half and then turn it upside down will the nucleus, ribosomes, and other parts of the cell fall out?” It’s always amazing to hear what science students are thinking or wondering about. I’m looking forward to seeing what fantastic questions we’ll get this year!

Cool Image: DNA Origami

Computer-generated sketch of a DNA origami folded into a flower-and-bird structure.

A computer-generated sketch of a DNA origami folded into a flower-and-bird structure. Credit: Hao Yan, Arizona State University.

This image of flowers visited by a bird is made of DNA, the molecule that provides the genetic instructions for making living organisms. It shows the latest capability of a technique called DNA origami to precisely twist and fold DNA into complex arrangements, which might find future use in biomedical applications. Continue reading

How Cells Manage Chance

We asked the heads of our scientific divisions to tell us about some of the big questions in fundamental biomedical science that researchers are investigating with NIGMS support. This article is the second in an occasional series that explores these questions and explains how pursuing the answers could advance understanding of important biological processes.

Sample slide, variability of mRNA in yeast cells
The number of copies of mRNA molecules (bright green) observed here in yeast cells (dark blue) fluctuates randomly. Credit: David Ball, Virginia Tech.

For some health conditions, the cause is clear: A single altered gene is responsible. But for many others, the path to disease is more complex. Scientists are working to understand how factors like genetics, lifestyle and environmental exposures all contribute to disease. Another important, but less well-known, area of investigation is the role of chance at the molecular level.

One team working in this field is led by John Tyson Exit icon at Virginia Tech. The group focuses on how chance events affect the cell division cycle, in which a cell duplicates its contents and splits into two. This cycle is the basis for normal growth, reproduction and the replenishment of skin, blood and other cells throughout the body. Errors in the cycle are associated with a number of conditions, including birth defects and cancer. Continue reading

Food for Thought: Nutrient-Detecting Brain Sensor in Flies

If you participated in a cupcake taste test, do you think you’d be able to distinguish a treat made with natural sugar from one made with artificial sweetener? Scientists have known for decades that animals can tell the difference, but what’s been less clear is how.

Fruit fly neurons in the brain (red) with nerve fibers (white) that extend to the gut.
For fruit flies, nutritive sugars activate a set of neurons in the brain (red) with nerve fibers (white) that extend to the gut. Credit: Jason Lai and Greg Suh, New York University School of Medicine.

Now, researchers at the New York University School of Medicine have identified a collection of specialized nerve cells in fruit flies that acts as a nutrient-detecting sensor, helping them select natural sugar over artificial sweetener to get the energy they need to survive.

“How specific sensory stimuli trigger specific behaviors is a big research question,” says NIGMS’ Mike Sesma. “Food preferences involve more than taste and hunger, and this study, which was done in an organism with many of the same cellular components as humans, gives us a glimpse of the complex interplay among the many factors.”

The study, described in the July 15 issue of Neuron, builds on the researchers’ earlier studies of feeding behavior that showed hungry fruit flies, even ones lacking the ability to taste, selected calorie-packed sugars over zero-calorie alternatives. The scientists, led by Greg Suh Exit icon and Monica Dus Exit icon, suspected that the flies had a molecular system for choosing energy-replenishing foods, especially during periods of starvation. Continue reading

How a Cell Knows Friend From Foe

We asked the heads of our scientific divisions to tell us about some of the big questions in fundamental biomedical science that researchers are investigating with NIGMS support. This article is the first in an occasional series that will explore these questions and explain how pursuing the answers could advance understanding of important biological processes.

Video screen shot showing different strains of amoeba cells in red and green.
This video shows different strains of amoeba cells in red and green. As cells move toward one another, they use two sets of proteins to recognize others from the same strain. When close relatives meet, their proteins match and the cells join together to form a multicellular structure. When cells from different strains meet, their proteins don’t match, so they can’t aggregate. Credit: Shigenori Hirose, Baylor College of Medicine.

Cells are faced with many decisions: When’s the best time to produce a new protein? To grow and split into two? To treat another cell as an invader? Scientists are working to understand how cells make these and many other decisions, and how these decisions contribute to health and disease.

An active area of research on cell decisions focuses on allorecognition, the ability of an organism to distinguish its own cells from those of another. Immune cells use a system called the major histocompatibility complex (MHC) to identify which cells belong to the body and which are foreign. The particular set of MHC proteins on the outer surface of a cell helps immune cells decide whether it does not belong and should be attacked.

But the system isn’t perfect. Invading pathogens can go undetected, and the body can mistake its own cells for intruders. Continue reading

Meet Nels Elde and His Team’s Amazing, Expandable Viruses

Nels Elde, Ph.D.
Credit: Kristan Jacobsen
Nels Elde, Ph.D.
Fields: Evolutionary genetics, virology, microbiology, cell biology
Works at: University of Utah, Salt Lake City
When not in the lab, he’s: Gardening, supervising pets, procuring firewood
Hobbies: Canoeing, skiing, participating in facial hair competitions

“I really look at my job as an adventure,” says Nels Elde. “The ability to follow your nose through different fields is what motivates me.”

Elde has used that approach to weave evolutionary genetics, bacteriology, virology, genomics and cell biology into his work. While a graduate student at the University of Chicago and postdoctoral researcher at the Fred Hutchinson Cancer Research Center in Seattle, he became interested in how interactions between pathogens (like viruses and bacteria) and their hosts (like humans) drive the evolution of both parties. He now works in Salt Lake City, where, as an avid outdoorsman, he draws inspiration from the wild landscape.

Outside the lab, Elde keeps diverse interests and colorful company. His best friend wrote a song about his choice of career as a cell biologist. (You can hear this song at the end of the 5-minute video Exit icon in which Elde explains his work.) Continue reading