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Zooming In on Meiosis

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Credit: Simone Köhler, Michal Wojcik, Ke Xu, and Abby Dernburg, University of California, Berkeley

Meiosis—the formation of egg and sperm cells—is a highly choreographed process that creates genetic diversity in all plants and animals, including humans, to make each of us unique. This kaleidoscopic image shows cells from a worm exchanging DNA during meiosis.

You can see a protein-based polymer tether (green) from what’s called the synaptonemal complex. The complex holds together partner chromosomes (magenta) to facilitate DNA exchange in nuclei (white). Moving from left to right are views of the molecular assembly that progressively zoom in on the DNA, revealing in exquisite detail (far right) the two paired partner chromosomes perfectly aligned. This is not just the familiar DNA double helix. This is a double helix made up of two double helices!

A Microbial Work of Art

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Sclupture of a bacterial colony

Credit: Scott Chimileski, Sylvie Laborde, Nicholas Lyons, Roberto Kolter, Harvard Medical School, Boston

Bacteria are single-celled organisms that are too small to see in detail without the aid of a microscope. So you might not think that zooming in on a batch of bacteria would provide the inspiration for a museum-worthy sculpture.

But, in fact, that’s exactly what you see in the image. Researchers grew in a lab dish Bacillus licheniformis, a usually benign bacterium from the soil that produces an enzyme used in laundry detergent. The bacteria self-organized into a sand dollar-like pattern to form a cohesive structure called a biofilm. The researchers then took a 3D scan of the living bacterial colony in the lab and used it to print this stainless steel sculpture at 12 times the dime-sized biofilm.

A Scientist and Conservation Photographer

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These stunning images of animals were taken by Susan McConnell, whose photographs have appeared in Smithsonian Magazine, National Geographic, Nature’s Best Photography, Africa Geographic, and a number of other publications. But photography is just part of her professional life. McConnell is best known as a developmental neurobiologist at Stanford University, Palo Alto, CA, and an elected member of the U.S. National Academy of Sciences.

How did McConnell find the time while tracing the development of the brain’s biocircuitry to launch a second career as a nature photographer? Her answer: Every research career has its seasons. When McConnell launched her lab in 1989 at the age of 31, she was up to her eyeballs recruiting staff, writing research grants, and pursuing many different leads in her quest to understand how neurons in the brain’s cerebral cortex are produced, differentiated, and then wired together into functional circuits.

Snapshots of Life: Finding Where HIV Hides

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Credit: Nadia Roan, University of California, San Francisco

Researchers have learned a tremendous amount about how the human immunodeficiency virus (HIV),  which causes AIDS, infects immune cells. Much of that information comes from studying immune cells in the bloodstream of HIV-positive people. Less detailed is the picture of how HIV interacts with immune cells inside the lymph nodes, where the virus can hide.

In this image of lymph tissue taken from the neck of a person with uncontrolled HIV infection, you can see areas where HIV is replicating (red) amid a sea of immune cells (blue dots). Areas of greatest HIV replication are associated with a high density of a subtype of human CD4 T-cells (yellow circles) that have been found to be especially susceptible to HIV infection.

Cool Videos: The Ghost in the Lab Dish?

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As Halloween approaches, lots of kids and kids-at-heart will be watching out for ghosts and goblins. So, to help meet the seasonal demand for scary visuals, I’d like to share this award-winning image that’s been packaged into a brief video.

The “ghoul” you see above is no fleeting apparition: it’s a mouse cell labelled to reveal its microtubules, which are dynamic filaments involved in cellular structure, transport, and motility. Graduate student Victor DeBarros captured this image a couple of years ago in the NIH-supported lab of Randall Duncan at the University of Delaware, Newark, as part of research on the rare skeletal disorder metatropic dysplasia (MD).

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