Year: 2015

Cool Images: A Halloween-Inspired Cell Collection

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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 fibroblasts with healthy skeletons.

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Turning Back Every Clock

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Clock
Scientists are studying which genes control biological clock gears and which genes are controlled by them. Credit: Stock image.

When daylight savings time ends this Sunday, we’ll need to adjust every clock in our homes, cars and offices. Our internal clocks will need to adjust too.

The body has a master clock in the brain, as well as others in nearly every tissue and organ. These biological clocks drive circadian rhythms, the physical, mental and behavioral changes we experience on a roughly 24-hour cycle. Your hunger in the morning and sleepiness at night, for example, are caused partly by clock gears in motion. These gears can get out of synch with the day-night cycle when the time changes or when we travel through time zones.

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Meet Sharon Cobb: Aiming to Understand Pain in Aging African Americans

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Sharon Cobb
Credit: UCLA School of Nursing
Sharon Cobb
Field: Nursing
Raised in: Los Angeles, California
Studied at: University of California, Berkeley; Charles R. Drew University; and University of California, Los Angeles
Musical skill: She can play the triangle if someone asks
If she wasn’t a scientist, she would be: An event planner for celebrity weddings

A single, life-defining moment is what often influences our choice of career paths. But for Sharon Cobb, three significant events empowered her to want to produce a change in society for those affected by health disparities.

First, in high school, she was offered the chance to shadow an OB/GYN nurse practitioner at King/Drew Medical Center in Los Angeles. There, Cobb saw firsthand the need for health care among some of the city’s most vulnerable residents and the challenges involved in delivering that care. This experience led her to pursue a career in nursing. Continue reading “Meet Sharon Cobb: Aiming to Understand Pain in Aging African Americans”

Help Spread the Word About Cell Day

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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

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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.

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Bacterial ‘Fight Clubs’ and the Search for New Medicines

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Competition encourages bacteria to produce secondary metabolites with therapeutic potential that they would otherwise hold in reserve. Credit: Michael Smeltzer, Vanderbilt University.

Bacteria hold a vast reservoir of compounds with therapeutic potential. They use these compounds, known as secondary metabolites, to protect themselves against their enemies. We use them in many antibiotics, anti-inflammatories and other treatments.

Scientists interested in developing new medicines have no shortage of places to look for secondary metabolites. There are an estimated 120,000 to 150,000 bacterial species on Earth. Each species is capable of producing hundreds of secondary metabolites, but often only under specific ecological conditions. The challenge for researchers is figuring out how to coax the bacteria to produce these compounds.

Now, Brian Bachmann and John McLean of Vanderbilt University and their teams have shown that by creating “fight clubs” where bacteria compete with one another, they can trigger the bacteria to make a wide diversity of molecules, including secondary metabolites. Continue reading “Bacterial ‘Fight Clubs’ and the Search for New Medicines”

“Award Season” for Science

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Science award
The biggest prizes each science “award season”: powerful glimpses into fundamental life processes that can yield deeper understanding of health and disease. Credit: Stock image.

Roll out the red carpet and shine up your shoes—it’s “award season” for science. The biggest prizes: powerful glimpses into fundamental life processes that can yield deeper understanding of health and disease.

For instance, the 2015 Albert Lasker Basic Medical Research Award that’s being presented today highlights the seminal work of two scientists on the DNA-damage response, a mechanism that protects the genomes of all living organisms. Chemicals, radiation and duplication errors during cell division are constantly harming our genetic material. Healthy cells respond with a complex network of proteins that work together to mend the damage and halt cell division until repairs are complete. If injury is beyond repair, the proteins trigger cell death. Errors in the DNA-damage response can lead to cancer, neurodegenerative disorders and immune deficiencies.

The scientists recognized today took important steps toward elucidating the mechanics of the DNA-damage response. Evelyn Witkin of Rutgers University established its existence and its basic features in bacteria. Continue reading ““Award Season” for Science”

How Cells Manage Chance

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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 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 “How Cells Manage Chance”

The Simple Rules Bacteria Follow to Survive

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Left: Football stadium. Right: Colored contoured lines showing the periodic stops in the growth of a bacterial colony
Football image credit: Stock image. The colored contoured lines show the periodic stops in the growth of a bacterial colony. Credit: Süel Lab, UCSD.

What do these images of football fans and bacterial cells have in common? By following simple rules, each individual allows the group to accomplish tasks none of them could do alone—a stadium wave that ripples through the crowd or a cell colony that rebounds after antibiotic treatment.

These collective behaviors are just a few examples of what scientists call emergent phenomena. While the reasons for the emergence of such behavior in groups of birds, fish, ants and other creatures is well understood, they’ve been less clear in bacteria. Two independent research teams have now identified some of the rules bacterial cells follow to enable the colony to persist. Continue reading “The Simple Rules Bacteria Follow to Survive”

Field Focus: Progress in RNA Interference Research

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Scientists first noticed what would later prove to be RNA interference when puzzling over an unexpected loss of color in petunia petals. Subsequent studies in roundworms revealed that double-stranded RNA can inactivate specific genes. Credit: Alisa Z. Machalek.

In less than two decades, RNA interference (RNAi)—a natural process cells use to inactivate, or silence, specific genes—has progressed from a fundamental finding to a powerful research tool and a potential therapeutic approach. To check in on this fast-moving field, I spoke to geneticists Craig Mello of the University of Massachusetts Medical School and Michael Bender of NIGMS. Mello shared the 2006 Nobel Prize in physiology or medicine with Andrew Fire Exit icon of Stanford University School of Medicine for the discovery of RNAi. Bender manages NIGMS grants in areas that include RNAi research.

How have researchers built on the initial discovery of RNAi?

A scientific floodgate opened after the 1998 discovery that it was possible to switch off specific genes by feeding microscopic worms called C. elegans double-stranded RNA that had the same sequence of genetic building blocks as a target gene. (Double-stranded RNA is a type of RNA molecule often found in, or produced by, viruses.) Scientists investigating gene function quickly began to test RNAi as a gene-silencing technique in other organisms and found that they could use it to manipulate gene activity in many different model systems. Additional studies led the way toward getting the technique to work in cells from mammals, which scientists first demonstrated in 2001. Soon, researchers were exploring the potential of RNAi to treat human disease.

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