Snapshots of Life: Muscling in on Development

Limb Muscles

Credit: Mary P. Colasanto, University of Utah, Salt Lake City

Twice a week, I do an hour of weight training to maintain muscle strength and tone. Millions of Americans do the same, and there’s always a lot of attention paid to those upper arm muscles—the biceps and triceps. Less appreciated is another arm muscle that pumps right along during workouts: the brachialis. This muscle—located under the biceps—helps your elbow flex when you are doing all kinds of things, whether curling a 50-pound barbell or just grabbing a bag of groceries or your luggage out of the car.

Now, scientific studies of the triceps and brachialis are providing important clues about how the body’s 40 different types of limb muscles assume their distinct identities during development [1]. In these images from the NIH-supported lab of Gabrielle Kardon at the University of Utah, Salt Lake City, you see the developing forelimb of a healthy mouse strain (top) compared to that of a mutant mouse strain with a stiff, abnormal gait (bottom).

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Snapshots of Life: A Van Gogh Moment for Pancreatic Cancer

Pancreatic Cancer

Credit: Nathan Krah, University of Utah,
Salt Lake City

Last year, Nathan Krah sat down at his microscope to view a thin section of pre-cancerous pancreatic tissue from mice. Krah, an MD/PhD student in the NIH-supported lab of Charles Murtaugh at the University of Utah, Salt Lake City, had stained the tissue with three dyes, each labelling a different target of interest. As Krah leaned forward to look through the viewfinder, he fully expected to see the usual scattershot of color. Instead, he saw enchanting swirls reminiscent of the famous van Gogh painting, The Starry Night.

In this eye-catching image featured in the University of Utah’s 2016 Research as Art exhibition, red indicates a keratin protein found in the cytoskeleton of precancerous cells; green, a cell adhesion protein called E-cadherin; and yellow, areas where both proteins are present. Finally, blue marks the cell nuclei of the abundant immune cells and fibroblasts that have expanded and infiltrated the organ as a tumor is forming. Together, they paint a fascinating new portrait of pancreatic ductal adenocarcinoma (PDAC), the most common form of pancreatic cancer.

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