Bookmark and Share

Contact: Diana Kenney, Marine Biological Laboratory
508-289-7139; dkenney@mbl.edu

WOODS HOLE, Mass.—How a brilliant-green sea slug manages to live for months at a time “feeding” on sunlight, like a plant, is clarified in a recent study published in The Biological Bulletin.

The authors present the first direct evidence that the emerald green sea slug’s chromosomes have some genes that come from the algae it eats.

These genes help sustain photosynthetic processes inside the slug that provide it with all the food it needs.

Importantly, this is one of the only known examples of functional gene transfer from one multicellular species to another, which is the goal of gene therapy to correct genetically based diseases in humans.

“Is a sea slug a good [biological model] for a human therapy? Probably not. But figuring out the mechanism of this naturally occurring gene transfer could be extremely instructive for future medical applications,” says study co-author Sidney K. Pierce, an emeritus professor at University of South Florida and at University of Maryland, College Park.

The rich green color of the photosynthesizing sea slug, Elysia chlorotica, helps to camouflage it on the ocean floor. Credit: Patrick Krug

The rich green color of the photosynthesizing sea slug, Elysia chlorotica, helps to camouflage it on the ocean floor. Credit: Patrick Krug

The team used an advanced imaging technique to confirm that a gene from the alga V. litorea is present on the E. chlorotica slug’s chromosome. This gene makes an enzyme that is critical to the function of photosynthetic “machines” called chloroplasts, which are typically found in plants and algae.

It has been known since the 1970s that E. chloritica “steals” chloroplasts from V. litorea (called “kleptoplasty”) and embeds them into its own digestive cells. Once inside the slug cells, the chloroplasts continue to photosynthesize for up to nine months—much longer than they would perform in the alga. The photosynthesis process produces carbohydrates and lipids, which nourish the slug.

How the slug manages to maintain these photosynthesizing organelles for so long has been the topic of intensive study and a good deal of controversy. “This paper confirms that one of several algal genes needed to repair damage to chloroplasts, and keep them functioning, is present on the slug chromosome,” Pierce says. “The gene is incorporated into the slug chromosome and transmitted to the next generation of slugs.” While the next generation must take up chloroplasts anew from algae, the genes to maintain the chloroplasts are already present in the slug genome, Pierce says.

“There is no way on earth that genes from an alga should work inside an animal cell,” Pierce says. “And yet here, they do. They allow the animal to rely on sunshine for its nutrition. So if something happens to their food source, they have a way of not starving to death until they find more algae to eat.”

This biological adaptation is also a mechanism of rapid evolution, Pierce says. “When a successful transfer of genes between species occurs, evolution can basically happen from one generation to the next,” he notes, rather than over an evolutionary time scale of thousands of years.

Citation:

Schwartz JA, Curtis NE, and Pierce SK (2014) FISH labeling reveals a horizontally transferred algal (Vaucheria litorea) nuclear gene on a sea slug (Elysia chlorotica) chromosome. Biol. Bull. 227: 300-312.

—###—

The Biological Bulletin is a peer-reviewed, trans-disciplinary international journal that publishes outstanding experimental research on a wide range of organisms and biological topics, with a focus on marine models. Published since 1897 by the Marine Biological Laboratory, it is one of America’s oldest and most respected journals.


The Marine Biological Laboratory (MBL) is dedicated to scientific discovery and improving the human condition through research and education in biology, biomedicine, and environmental science. Founded in Woods Hole, Massachusetts, in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.

Bill Klimm, captain of the Gemma, the MBL's collecting vessel. Credit: Daniel Cojanu

Bill Klimm, captain of the Gemma, the MBL’s collecting vessel. Credit: Daniel Cojanu

When Nature began pursuing a story on “unsung heroes” in science — the behind-the-scenes staff who make the whole operation happen — it became clear that plenty of people at the MBL fit that bill. One is Bill Klimm, captain of the Gemma, who as a longtime fisherman knows not only how to operate the boat, but where to find the elusive fish and other marine organisms used for MBL research. Nature published a wonderful profile of Klimm this week, including the video below. Thanks to Bill, Dave Remsen, Dan Sullivan, and everyone who works hard every day to make the MBL’s collecting operation succeed!

 

By Jennifer Walton

Would you like to spend part of your summer at the MBLWHOI Library studying or writing?

Karush-photo-for-webThe Fred Karush Endowed Library Readership provides the recipient with a study desk and library services in the MBLWHOI Library for one summer month, with limited funds granted for travel and/or housing. Applications are being accepted now for summer 2015; the deadline to apply is February 15.

The MBLWHOI Library has long been a working home for scholars and researchers in Woods Hole, offering a unique and historic environment for scientific study and writing. A Library Reader desk in the book stacks is a quiet space in the middle of the vibrant MBL community.

Here are a few comments from researchers and scholars on the MBLWHOI Library Reader experience:

“Every time I have a big writing project, grant proposal, or review paper, I try to find an excuse that will allow me to do it at a desk in the MBLWHOI Library. In many ways, the library is the most valuable feature of the MBL. It contains one of the largest, most comprehensive, and most complete collections of biological and oceanographic primary literature in the country, perhaps the world …  Although it comes as a surprise to my students, not everything is available on the Internet or for free—but it is usually in the stacks of the MBLWHOI Library.”

Sidney K. Pierce, Emeritus Professor of Biology, University of Maryland and Emeritus Professor of Biology, University of South Florida

“The MBL journals collection is one of the most inspiring library collections I’ve ever encountered. It’s the perfect source for anyone interested in current biological research and its historical origins, valuable not only to biologists, but also to historians and philosophers of science like me.”

Florian Huber, University of Vienna

Questions? Please contact Jen Walton, Coordinator of Library Services, at 508-289-7452; .

 

FOR IMMEDIATE RELEASE: January 7, 2015
CONTACT: Diana Kenney
dkenney@mbl.edu; 508-289-7139

Get Your Hands On Research! Apply Now for a Fellowship
In the MBL’s Science Journalism Program

WOODS HOLE, Mass. – The Marine Biological Laboratory (MBL), an international center for research and education in biological and environmental sciences and an affiliate of the University of Chicago, invites journalists to apply for a fellowship in its Logan Science Journalism Program, to be held May 27 to June 5, 2015. The deadline to apply is March 2.

Since 1986, this program has plunged journalists into laboratory or field research in one of the most dynamic settings for scientific discovery in the world. Fellows choose between one of two courses: the Environmental Hands-On Research Course or the Biomedical Hands-On Research course. The main emphasis is on research activities, enriched by discussions, scientific talks, and excursions.

“This kind of [research] experience should be a requisite part of the career of any science journalist.”
—Erik Olsen, The New York Times (2013 MBL Environmental Fellow)

Alumni of the MBL’s Logan Science Journalism Program include hundreds of prominent journalists from U.S. and international media outlets. Read some of their testimonials here.

Salt marsh at Plum Island, Mass. Credit: DS Johnson

Salt marsh at Plum Island, Mass. Credit: DS Johnson

Fellows in the 2015 Environmental Hands-On Course will experience field and laboratory science immersion both at the MBL and at the Plum Island Long Term Ecological Research site north of Boston, Mass., where they will discover firsthand how human activities are shaping the health and functioning of a coastal ecosystem.

Fellows in the Biomedical Hands-On Course will gain exposure to the fundamental techniques and concepts of cell and molecular biology that underlie many approaches to current biomedical research.

Limited extended-stay fellowships will be awarded to Biomedical fellows to remain in Woods Hole during the dynamic MBL summer season, and to Environmental fellows to travel to Toolik Field Station in Arctic Alaska (pending program funding). Completion of the relevant Hands-On Course is a requirement to apply for an extended-stay fellowship.

To apply, please visit http://www.mbl.edu/sjp/ and submit an application by March 2, 2015. Domestic travel, room and board, and all course and activity fees are underwritten by the fellowship.

—###—

The Marine Biological Laboratory (MBL) is dedicated to scientific discovery and improving the human condition through research and education in biology, biomedicine, and environmental science. Founded in Woods Hole, Massachusetts, in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.

MBL Adjunct Scientist Amy Gladfelter can now add “video producer” to her resume. Tapped to make her science “visible to the world” by Celldance Studios, a project of the American Society for Cell Biology (ASCB), Gladfelter came up with an aesthetically beautiful, simply told video about her discoveries of what goes wrong when cells form toxic aggregates, such as in Alzheimer’s disease. Her mini-movie, called “Companions in Discovery,” was filmed partly at MBL and partly at Dartmouth College, where she is an Associate Professor of Biological Sciences. It premiered for an appreciative audience in December at the ASCB annual meeting in Philadelphia.

“I like the end of the film, where members of [Gladfelter’s] lab talk briefly on camera. These young faces are the future of cell biology,” said Simon Atkinson, chairman of the ASCB’s Public Information Committee, which sponsors Celldance Studios.

Celldance Studios gave Gladfelter $1,000 to underwrite her costs, and provided video editing and post-production support. The original score is by Hollywood film composer Ted Masur, son of cell biologist Sandra Masur. More information is here.

 

« Previous PageNext Page »