The world beneath our skin is full of movement. Hemoglobin in our blood grabs oxygen and delivers it throughout the body. Molecular motors in cells chug along tiny tubes, hauling cargo with them. Biological invaders like viruses enter our bodies, hijack our cells and reproduce wildly before bursting out to infect other cells.
To make sense of the subcutaneous world, Janet Iwasa, a molecular animator at the University of Utah, creates “visual hypotheses”—detailed animations that convey the latest thinking of how biological molecules interact.
“It’s really building the animated model that brings insights,” Iwasa told Biomedical Beat in 2014. “When you’re creating an animation, you’re really grappling with a lot of issues that don’t necessarily come up by any other means. In some cases, it might raise more questions, and make people go back and do some more experiments when they realize there might be something missing.”
Iwasa has collaborated with numerous scientists to develop animations of a range of biological processes and structures . Recently, she’s undertaken an ambitious, multi-year project to animate HIV reproduction .
Credit: Wikimedia Commons, Usman Bashir.
Natural habitat: Deciduous forest soil and moist leaf litter
Favorite food: Bacteria
Top speed: 8 micrometers per minute
Like the athletes in Rio, the world’s most highly advanced microbial runners recently gathered in Charlestown, Massachusetts, to find out which ones could use chemical cues to most quickly navigate a maze-like microfluidic racecourse. The winners’ prize: credit for helping scientists learn more about how immune system cells navigate through the human body on their way to fight disease.
Credit: Daniel Irimia of Massachusetts General Hospital, and Monica Skoge and Albert Bae of the University of California, San Diego.
The finalists were a group of soil-dwelling slime molds called Dictyostelium that were genetically engineered by a pair of Dutch biochemists to detect minuscule chemical changes in the environment. The racers used their enhanced sense of “smell” to avoid getting lost on their way to the finish line.
While researchers have been racing the genetically souped-up microbes at annual events for a few years—another competition is scheduled for October 26—scientists have been studying conventional Dictyostelium for decades to investigate other important basic life processes including early development, gene function, self/non-self recognition, cell-type regulation, chemical signaling and programmed cell death. Continue reading “Interview With a Slime Mold: Racing for New Knowledge”
Credit: Alejandro Sánchez Alvarado, Stowers Institute for Medical Research.
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 “Interview With a Worm: We’re Not So Different”
More than 70 percent of new drugs approved within the past 30 years originated from trees, sea creatures and other organisms that produce substances they need to survive. Since ancient times, people have been searching the Earth for natural products to use—from poison dart frog venom for hunting to herbs for healing wounds. Today, scientists are modifying them in the laboratory for our medicinal use. Here’s a peek at some of the products in nature’s medicine cabinet.
A protein called draculin found in the saliva of vampire bats is in the last phases of clinical testing as a clot-buster for stroke patients. Vampire bats are able to drink blood from their victims because draculin keeps blood from clotting. The first phases of clinical trials have shown that the protein’s anti-coagulative properties could give doctors more time to treat stroke patients and lower the risk of bleeding in the brain.
Continue reading “Nature’s Medicine Cabinet”
DNA researcher Rosalind Franklin first described an unusual form of DNA called the A-form in the early 1950s (Franklin, who died in 1958, would have turned 95 next month). New research on a heat- and acid-loving virus has revealed surprising information about this DNA form, which is one of three known forms of DNA: A, B and Z.
“Many people have felt that this A-form of DNA is only found in the laboratory under very non-biological conditions, when DNA is dehydrated or dry,” says Edward Egelman in a University of Virginia news release about the recent study. But considered with earlier studies on bacteria by other researchers, the new findings suggest that the A-form “appears to be a general mechanism in biology for protecting DNA.” Continue reading “Unusual DNA Form May Help Virus Withstand Extreme Conditions”
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.
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 “How a Cell Knows Friend From Foe”
Icelandic hot springs are the natural habitat of Rhodothermus marinus, one of many species of thermophiles that the Gennis Lab studies to better understand membrane proteins. Credit: Stock image.
As the temperature climbs, most humans look for ways to cool down fast. But for some species of microorganisms, a midsummer heat wave isn’t nearly hot enough. These heat lovers, known as thermophiles, thrive at temperatures of 113°F or more. They’re often found in hot springs, geysers and even home water heaters.
Like humans and other organisms, thermophiles rely on proteins to maintain normal cell function. While our protein molecules break down under intense heat, a thermophile’s proteins actually work more efficiently. They also tend to be more stable at room temperature than our own. An NIH-funded research team is taking advantage of this property of thermophiles to better understand a group of human proteins commonly targeted by today’s medicines.
Read more about the team’s thermophile research in this Inside Life Science article.