Interview With a Worm: We’re Not So Different

Credit: Alejandro Sánchez Alvarado, Stowers Institute for Medical Research.
Schmidtea mediterranea
Home: Freshwater habitats along the Mediterranean
Party trick: Regenerating its head
Most charismatic feature: Eyespots
Work site: Science labs worldwide

The planarian has a power few creatures can match. Remove its head, its tail or nearly any of its body parts, and this aquatic flatworm will simply grow it back. Humans can’t do that, of course. And yet many of the genes that help the planarian regenerate are also found in us. To learn more about this tiny marvel, we “interviewed” a representative. 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
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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Turning Back Every 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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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

“Award Season” for Science

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 Exit iconthat’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

The Simple Rules Bacteria Follow to Survive

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

Field Focus: Progress in RNA Interference Research

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 Exit icon 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. Continue reading

Meet Sarkis Mazmanian and the Bacteria That Keep Us Healthy

Sarkis K. Mazmanian
Credit: New York Academy of Sciences
Sarkis K. Mazmanian, Ph.D.
Born in: The country of Lebanon, moved to Los Angeles when he was 1
Fields: Microbiology, immunology, neuroscience
Works at: California Institute of Technology
Awards won: Many, including the MacArthur Foundation “Genius” grant
Most proud of: The success of his trainees! “There’s nothing that comes close to the gratification and joy I feel when a student or research fellow goes on to be an independent scientist.”
When not in the lab or mentoring students, he’s: Spending time with his family, including his 1-year-old-son or going for an occasional run

As a child, Sarkis Mazmanian frequently took things apart to figure out how they worked. At the age of 12, he dismantled his family’s entire television set—to the dismay of his parents and the unsuccessful TV repairman.

“I wasn’t aware of this at the time, but maybe that was some sort of a foreshadowing that I would enjoy science,” Mazmanian says. “Scientists take biological systems apart to understand how they work.”

Mazmanian never thought he’d become a microbiologist, let alone a leading expert in the field. He began studying microbiology at the University of California, Los Angeles (UCLA), because it was the major that allowed him to do the most hands-on research. But as soon as he entered the field, he fell in love with the complexities of microbial organisms and the efficiency of their functions. 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