MBL


WOODS HOLE, Mass.—Vision has been studied inside and out for more than a century, and all this data has resulted in confident textbooks presenting the visual system as essentially understood. But María Gomez and Enrico Nasi, adjunct scientists at the Marine Biological Laboratory (MBL), don’t agree. They have spent the last several years investigating non-visual photoreceptors, cells whose function remains elusive in eyes filled with rods and cones. They reveal an important clue to how these cells work—how calcium triggers the electrical light response— in a recent paper published in Proceedings of the National Academy of Sciences.

Enrico Nasi and Maria del Pilar Gomez

Enrico Nasi and Maria del Pilar Gomez

Studies of vision traditionally divided light-sensitive cells into two distinct classes: those of vertebrates and those of invertebrates. The two classes were so different from each other that they were thought to represent two separate lines of evolution. But a few phenomena presented problems with this view. The most dramatic is the fact that blind people, who lack functioning rods and cones—the only photoreceptive cells previously thought to exist in vertebrates—can recover from jet lag, somehow sensing the light that resets their circadian rhythms. “A new type of photosensitive cell was later discovered in the mammalian eye that is responsible for these functions,” says Nasi. “Another dogma bites the dust.”

It is these non-visual photoreceptors, sometimes called circadian photoreceptors, that Nasi and Gomez, both professors at the Universidad Nacional de Colombia, were interested in studying. “What are these sensors? The idea that they might be just like photoreceptors of invertebrates—this is beyond blasphemy,” says Nasi. If true, “this leads to rewriting the evolutionary history of vision.” But studying these cells presented a few practical challenges. In vertebrates, the cells are few and far between, and have no unique shapes or markers to make them easy to find.

Amphioxus can grow as long as 2.5 inches, and it is very difficult to tell their head from their tail. Other than that, they are a very useful animal model. Photo by Hans Hillewaert.

Amphioxus can grow as long as 2.5 inches, and it is very difficult to tell their head from their tail. Other than that, they are a very useful animal model. Photo by Hans Hillewaert.

So Gomez and Nasi turned to an unassuming, fish-like invertebrate called a lancelet or amphioxus. This creature holds a unique place on the evolutionary tree of life, at the branching point between vertebrates and invertebrates. It has other advantages: the photoreceptors Gomez and Nasi were interested in were easy to find and experiment on. The evidence they found in the simple amphioxus suggests that vertebrates’ non-visual photoreceptors may mimic those found in amphioxus — that the visual systems of vertebrates and invertebrates are not as different as previously thought.

Their paper tackles the final step of the pathway that lets these photoreceptors translate incoming light into signals to the organism. Most of the pathway was already known, but solid evidence for the last step was elusive: How was light converted to an electrical cell signal that could be communicated to other cells?

Gomez and Nasi investigated the flood of calcium that is released when the circadian photoreceptors were exposed to light. They showed that calcium provoked the electrical cell signal, very similar to what happens with normal light stimulation. “It reproduces the native response,” says Gomez. This flood of calcium is the link that lets these photoreceptors communicate with the rest of the organism.

“We’re rather happy to see something that fully reproduces the light response for the first time,” Nasi says. But, he adds, “We don’t want to make claims that this is going to be general to all species.” Whether this discovery proves to be common in other species or not, it’s clear the field of vision and light-sensing cells still has much to reveal.

Citation:
Peinado G et al (2015). Calcium activates the light-dependent conductance in melanopsin-expressing photoreceptors in amphioxus. PNAS, DOI: 10.1073/pnas.1420265112

By Rachel Buhler

Two journalists who received fellowships from the MBL Logan Science Journalism Program are spending the next week with scientists pursuing environmental field research at Toolik Field Station in Arctic Alaska, including studies of global climate change.

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Michael Werner and Meera Subramanian at the Arctic Circle, 150 miles north of Fairbanks.

The two fellows, freelance journalist Meera Subramanian and freelance journalist/ filmmaker Michael Werner, both attended the program’s hands-on course at the MBL in June, undertaking field and laboratory research to “step into the shows of the scientists they cover.”  Last Tuesday, they flew into Fairbanks, Alaska, as the starting point for their journey to Toolik, which entails a minimum eight-hour drive and a passage across the Arctic Circle.

Subramanian has been blogging  — with striking photos and videos of the Arctic tundra and its scientist inhabitants — on the program’s blog, “A Toolik Field Journal.”

Over the years, the Logan Science Journalism Program has granted fellowships to hundreds of journalists from prominent news organizations, including The New York Times, The Wall Street Journal, Science, National Public Radio, The Washington Post, USA Today, CNN, and Scientific American. Journalists from Africa, Brazil, Sweden, India, Japan, the United Kingdom and other countries have also received fellowships.

Ever wonder what it takes to keep MBL scientists working away? Here’s a clue, in the form of a time-lapse video of the daily upkeep required for the many zebrafish being studied at the MBL this summer. University of Chicago undergraduates Melissa Li and Clara Kao pressed “go” on a video camera and then went about their daily routine of feeding, cleaning, and generally caring for all the fish in the Zebrafish Facility. “We basically make sure everyone is happy and healthy,” Kao says. The 24-second video went up on a blog they’re keeping on their summer of research at the MBL: Summer People, Some Are Not (tagline: Some Are Zebrafish).

http://summerpeoplesomearenot.tumblr.com/post/123742373728/the-daily-grind


These two rising juniors are working in Jonathan Gitlin’s lab this summer, a change from the labs they work in back in Chicago. “When you switch labs for the summer, you get a different sort of snippet of the scientific world,” Li says. Both are interested in coming back to the MBL after the summer is over- Kao is in fact here for her second summer, and is interested in coming back for the Physiology course. With any luck, the blog and video collection will get a chance to expand.

The family, friends, and colleagues of Catherine N. Norton (1941-2014), former director of the MBLWHOI Library, gathered in Lillie Auditorium on June 19 to honor her memory. As befitting Norton, who was ever-positive and energetic, the event was inspiring, enlightening, and celebratory of her life, family, and pioneering professional accomplishments.

Family, friends and colleagues of Cathy Norton gathered in Lillie Auditorium to celebrate her life. Credit: Tom Kleindinst

Cathy Norton’s family, friends, and colleagues gathered in Lillie Auditorium to share stories of her life and great contributions to library science. Credit: Tom Kleindinst

Speakers at the celebration honored Norton’s vision and vibrancy, and her major legacy to the library sciences worldwide through her prescient leadership in establishing digital collections, databases, and informatics tools at the MBLWHOI Library. Excerpts from the speakers’ remarks are below.

Diane Rielinger, co-director of the MBLWHOI Library, announced the Catherine N. Norton Endowed Fellowship, which has received donations from more than 110 family members, friends, and colleagues. This endowed fund will support projects by students or early-career fellows that use the MBLWHOI Library or Archives and uphold the principles Norton championed by being “openly accessible, collaborative, innovative, connective, and laying the foundation for new scientific knowledge.”

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Cathy always made sure we thought big. She encouraged us to see only opportunities—there were never problems. She didn’t just embrace technology; she pushed it forward with innovative programs that increased access and discovery, such as the Biodiversity Heritage Library. Cathy made sure our library was the first one out of the gate to digitize our collection with the project’s funding, and we developed procedures and policies that others adopted when they started scanning their collections. We learned an incredible amount so fast. — Diane Rielinger, Co-director, MBLWHOI Library

Cathy was one of the most amazingly effective and fun people I have ever worked with. She was a larger-than-life-sized person. Cathy was held in very high repute in library circles: She put MBL in the world league of libraries. And the most important thing to her was family.
— Donald Lindberg, Director Emeritus, National Library of Medicine

Cathy was far ahead of the curve in the Woods Hole community with respect to electronic journals and databases and “informatics.” The community owes a great debt of gratitude to Cathy for her vision, leadership, and hard work that kept the MBLWHOI Library at the forefront of library science and services, and well poised for the future. I assume that by now Cathy has assumed leadership of the Celestial Library and Archives. If so, they are in for an exciting time in the Celestial Realm! — John Farrington, Dean Emeritus, Woods Hole Oceanographic Institution

Cathy exemplified the “sanguine” temperament: open, caring, creative, bubbly, open to human beings but concerned about subject matter. Years ago, I asked her whether a journal should be published in print or digital formats. She said, “Do it both ways: for the present and for the future.” — Gerald Weissmann, Editor-in-Chief, The FASEB Journal and MBL Trustee Emeritus

My work with Cathy was a wonderful ride. We managed to be in the right place and time when new Internet technology came along and she found the money to wire the MBL. She enabled and supported me in the ability to discover and learn by doing, and she also gave me critical life lessons in how to lead a team. And Cathy always managed to have a lot of fun along the way. — David Remsen, director of MBL Marine Resources, who worked with Norton on MBL information systems (including the development of uBio) from 1991-2006

Cathy was a force of nature. The lessons she taught to all of us graduate students on the digital History of the MBL Project were a result of her indomitable spirit, pushing through every roadblock, and her joie de vivre. We carry these qualities forward in the project.
— Kate MacCord, project manager, MBL History Project

Cathy was exceedingly easy to love. She was an audacious friend. — John Monahan, family friend

I never met Cathy, but this is what I have heard about her: “inspirational but funny,” “very determined but kind,” “incredibly focused but managed to be positive.” These are the attributes we want to continue at MBL. — Hunt Willard, MBL President and Director

Audience members also shared their memories, many humorous, touching, or revealing of Norton’s “can-do” spirit. The memorial concluded with music performed by the Falmouth a capella group Notescape.

 

If you check the MBL’s Twitter feed during the summer months, you’ll be treated to quick, highly enthusiastic, and often visually beautiful dispatches from the MBL’s Summer Courses. The students and faculty are pursuing up-to-the-minute questions in life sciences research using a wide array of high-end imaging equipment, and some of the images they produce are eye-popping. Here are just a few recent Twitter posts from MBL students and faculty:

Vincent Boudreau (@viboud), a graduate student in the Physiology Course from University of North Carolina, Chapel Hill, Tweeted out this video, which he and several students made during the course’s biochemistry bootcamp under the supervision of Sabine Petry of Princeton University and Robert Fischer of the National Institutes of Health. “This bootcamp experiment taught us students how to do the biochemical legwork involved to get these microtubules to give us such stunning images,” Boudreau says. Microtubules (red) can be seen branching off of one another, marked by the green EB1 protein at their outwardly growing extremity. Video made with a Nikon TIRF microscope.

The MBL Embryology Course, tweeting under the hashtag #embryo2015, has shared one striking image after another. This is a tardigrade (a bizarre-looking, microscopic, water-dwelling animal) imaged with light-sheet microscopy by two students in the course: Christina Zakas, a post-doc at New York University who tweets @CZakDerv, and Nick Shikuma, a post-doc at Caltech.

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Tardigrade stained with DAPI to highlight nuclei and imaged on the Zeiss lighsheet Z1. Credit: C. Zakas and N. Shikuma, MBL Embryology course

Speaking of Embryology, several students in the course are blogging about their MBL experiences at the Node, an online community resource run by The Company of Biologists.  Check out their impressions of the course — its sheer intensity, its “exquisite coordination,” and the fun that balances all the hard work.

Embryology Course Co-director Alejandro Sánchez Alvarado, an expert Tweeter, once in a while reminds the students to step back from the bench, take a deep breath, and enjoy the beauty of Woods Hole. He called this scene “the rewards of Eel Pond after a rich day of learning and experimentation.”

Eel Pond, Woods Hole. Credit: Alejandro Sánchez Alvarado of the Stowers Institute/HHMI

Eel Pond, Woods Hole. Credit: Alejandro Sánchez Alvarado of the Stowers Institute/HHMI

 

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