Archive for February, 2015

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Buzzards Bay, Eel Pond, Great Harbor are in a deep-freeze. Our hardworking MBL grounds crews have been plowing, shoveling, sanding, and carving narrow walkways throughout campus since January. Shoes, cars,and stairwells are filthy, parking lots are flanked by ugly snow mountains, and patience with snow shovels, overcoats, scarves, gloves, boots, ear warmers, etc., is quickly waning. Even the Eel Pond ducks seem to be crying “UNCLE!” And more snow is predicted for this week.

So how are we surviving the tough winter weather?

Woods Hole’s natural, transient beauty (less the parking lots) keeps us charmed and impressed. Gorgeous sunsets, glimmering snowscapes, ice-capped shorelines, and oddly translucent waters make Woods Hole appear extraordinarily shiny and picturesque. It’s cold and inconvenient, but we all agree the village looks pretty darned good in snow.

Along with breathtaking winter views, good old New England fun energizes and entertains us, despite the bitter cold temperatures. Just today, at lunchtime, a hearty handful of ice skaters ventured out onto a solidly frozen Eel Pond. (The last time the pond froze was more than a decade ago, so this was quite a novelty for most.) Colleagues bundled up and headed out to the dock to watch the skaters, or to embark on their own personal historic walk across the water they are used to boating on. (Yes, that is MBL’s Gemma Captain Bill Klimm donning skates and joining in a round of pick-up hockey. No collecting boat trips today!)

Yes, Woods Hole is exceptionally beautiful and interesting under winter’s weight. But, really, spring is welcome anytime now….

— by Beth Liles

Photos by Hunt Willard, Pam Wilmot, and Beth Liles.

 

 

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The MBL-UChicago-Argonne Exploratory Research Fund provides seed funding for UChicago/Argonne collaborations with MBL resident and Whitman scientists. Congratulations to the first recipients of these awards, who are listed below. The University is accepting a second round of proposals until February 20. Please see a feature article about the program here.


First Recipients of MBL-UChicago-Argonne Exploratory Research Fund Awards

  • Jocelyn Malamy and Joel Smith: “Clytia hemisphaerica, a New Marine Model for Regeneration”
  • Patrick La Rivière, Hari Shroff, and Daniel Colón-Ramos: “Improving diSPIM Microscopy Through Advanced Computational Methods”
  • Stephanie E. Palmer and Roger T. Hanlon: “Quantifying Cuttlefish Camouflage”
  • Gordon Kindlmann, Rudolf Oldenbourg, and Nicola Ferrier: “Light Field Imaging of Anisotropic Materials”
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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.

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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.