The CRISPR gene-editing tool was recognized today by Science magazine as its “breakthrough of the year.” We support a number of researchers working in this exciting area and have featured it on this blog. To learn more about this exceptionally promising new method, see below for our illustrated explanation of the CRISPR system and its possible applications.
Last summer, we shared findings from Gürol Süel and colleagues at the University of California, San Diego, that bacterial cells in tight-knit microbial communities called biofilms expand in a stop-and-go pattern. The researchers concluded that this pattern helps make food at the nutrient-rich margin available to the cells in the starved center, but they didn’t know how. They’ve now shown that the cells use electrochemical signaling to communicate and cooperate with each other.
Because nutrients and other signals cells use to sense each other and their environment move rather slowly, the researchers looked for a faster, more active communication system in biofilms of the bacterium B. subtilis. They focused on electrical signaling via potassium, a positively charged ion that, for example, our nerve and muscle cells use to send or receive signals. Continue reading
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
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.
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.
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
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
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
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 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
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