Month: May 2017

Sea Urchin Regeneration May Help Us Understand Aging

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Sea urchin

The variegated sea urchin typically lives for about 4 years in the wild. The close-up view shows the sea urchin’s spines and tube feet that regrew after being removed 15 days earlier. Credit: Helena Reinardy (left) and Andrea Bodnar (right), Bermuda Institute of Ocean Sciences.

If you’ve ever been to the beach and walked around the rocks during low tide, you’ve probably seen a sea urchin. You may not have known that sea urchins found along the Pacific shore can live for more than 100 years. What’s even cooler is that, as they age, they don’t seem to lose their abilities to reproduce or regenerate damaged body parts. While different species of sea urchins have varying life expectancies, they all seem to share fountain-of-youth characteristics. For these and other reasons, scientists study sea urchins to investigate aging and other basic life processes. Continue reading “Sea Urchin Regeneration May Help Us Understand Aging”

Beauty is in the Eye

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Our eyes are the gateway to countless brilliant sights. However, as evidenced by the images on this page, the eye itself can be breathtakingly exquisite as well. This May, as we celebrate Healthy Vision Month with the National Eye Institute, we hope sharing the beauty hidden in your eyes will inspire you to take the necessary steps to protect your vision, prevent vision loss and make the most of the vision you have remaining.

Visit NEI to learn more about caring for your eyes.

Happy Healthy Vision Month!

Mammalian eye

Eyes are beautiful, and they take on a whole new look in this agate-like image, which highlights just how complex mammalian eyes really are. Researchers used staining and imaging techniques to turn each of the 70-plus cell types in this mouse eye a different color. The image won first place in the 2011 International Science and Engineering Visualization Challenge. Credit: Bryan William Jones, University of Utah Moran Eye Center.
Mouse eye

This burst of starry points is actually part of the retina from a mouse eye. The image comes from a research project investigating the promise of gene therapy for glaucoma. Untreated glaucoma is a leading cause of blindness. The disease is characterized by the death of cells called retinal ganglion cells. Scientists are hoping to deliver gene therapy to these cells as a treatment for glaucoma. In this photo, a fluorescent protein (GFP) lights up to show the location of retinal ganglion cells—and to reveal how well the proposed gene therapy technique might work. Credit: Kenyoung Kim, Wonkyu Ju and Mark Ellisman, National Center for Microscopy and Imaging Research, University of California, San Diego.
Mouse eye

What appears as a tree branch painstakingly wrapped in green wire is a microscopic blood vessel from the retina at the back of a mouse eye. These vessels can help diagnose conditions such as glaucoma and diabetic eye disease. The vessels also have a characteristic appearance in people with high blood pressure. This detailed image was created to help scientists understand what happens in a genetic disease called neurofibromatosis, in which tumors begin to form on nerve tissue. Credit: National Center for Microscopy and Imaging Research, University of California, San Diego.
Mouse eye

Like a colorful fiber-optic network, this microscopic layer from a mouse’s eye relays information from the retina to the brain. Retinal ganglion neurons (orange) and their associated optic nerve fibers (red) are overlaid with blood vessels (blue) and spidery glial cells (green). By comparing detailed images of healthy eye tissues with similar images of a diseased eye, researchers can learn about changes in biology that occur as eye diseases develop. Credit: National Center for Microscopy and Imaging Research, University of California, San Diego.

The Endoplasmic Reticulum: Networking Inside the Cell

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Like a successful business networker, a cell’s endoplasmic reticulum (ER) is the structure that reaches out—quite literally—to form connections with many different parts of a cell. In several important ways, the ER enables those other parts, or organelles, to do their jobs. Exciting new images of this key member of the cellular workforce may clarify how it performs its roles. Such knowledge will also help studies of motor neuron and other disorders, such as amyotrophic lateral sclerosis (ALS), that are associated with abnormalities in ER functioning.

Structure Follows Function

Illustration of some of the jobs that the ER performs in the cell.

An illustration of some of the jobs that the endoplasmic reticulum (ER) performs in the cell. Some ER membranes (purple) host ribosomes on their surface. Other ER membranes (blue) extending into the cytoplasm are the site of lipid synthesis and protein folding. The ER passes on newly created lipids and proteins to the Golgi apparatus (green), which packages them into vesicles for distribution throughout the cell. Credit: Judith Stoffer.

Initiated in 1965, the Postdoctoral Research Associate Program (PRAT) is a competitive postdoctoral fellowship program to pursue research in one of the laboratories of the National Institutes of Health. PRAT is a 3-year program providing outstanding laboratory experiences, access to NIH’s extensive resources, mentorship, career development activities and networking. The program places special emphasis on training fellows in all areas supported by NIGMS, including cell biology, biophysics, genetics, developmental biology, pharmacology, physiology, biological chemistry, computational biology, immunology, neuroscience, technology development and bioinformatics

The ER is a continuous membrane that extends like a net from the envelope of the nucleus outward to the cell membrane. Tiny RNA- and protein-laden particles called ribosomes sit on its surface in some places, translating genetic code from the nucleus into amino acid chains. The chains then get folded inside the ER into their three-dimensional protein structures and delivered to the ER membrane or to other organelles to start their work. The ER is also the site where lipids—essential elements of the membranes within and surrounding a cell—are made. The ER interacts with the cytoskeleton—a network of protein fibers that gives the cell its shape—when a cell divides, moves or changes shape. Further, the ER stores calcium ions in cells, which are vital for signaling and other work.

To do so many jobs, the ER needs a flexible structure that can adapt quickly in response to changing situations. It also needs a lot of surface area where lipids and proteins can be made and stored. Scientists have thought that ER structure combined nets of tubules, or small tubes, with areas of membrane sheets. However, recent NIGMS PRAT (Postdoctoral Research Associate; see side bar) fellow Aubrey Weigel, working with her mentor and former PRAT fellow Jennifer Lippincott-Schwartz of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (currently at the Howard Hughes Medical Institute in Virginia) and colleagues, including Nobel laureate Eric Betzig, wondered whether limitations in existing imaging technologies were hiding a better answer to how the ER meets its surface-area structural needs in the periphery, the portion of the cell not immediately surrounding the nucleus. Continue reading “The Endoplasmic Reticulum: Networking Inside the Cell”