Ocean Genome Legacy Inc.

Ipswich, MA, United States

Ocean Genome Legacy Inc.

Ipswich, MA, United States

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News Article | April 17, 2017
Site: motherboard.vice.com

The shells of a mysterious, three-foot-long shipworm species were first documented in the late 1700s, but the worm always managed to stay more or less out of the spotlight, and has largely avoided being researched. Now, scientists have tracked down, dissected, and researched the elusive shipworm, which has been chilling in the Philippines all this time. "We've known about these creatures a long time," Daniel Distel, the research professor and the executive director of Ocean Genome Legacy, a marine research organization at Northeastern University in Boston, said in a phone interview. He's the co-author of a new paper describing the shipworm, in the journal Proceedings of the National Academy of Sciences. "I've been looking for them for about 20 years. It was pretty crazy the first time we saw them." The Kuphus polythalamia that Distel and other scientists found and studied spends its days in a log storage pond in Mindanao, surrounded by the smell of rotten eggs. This is because the organic-rich mud it lives in emits hydrogen sulphide, which the shipworm (a type of saltwater clam) consumes to survive—unlike other shipworms, which munch on wood. Distel and his collaborators started chasing this species after a documentary that showed a patch of K. polythalamia shells aired on Philippine television, giving them a useful hint about where to find them. Senior author Margo Haygood was in the lab the first time a live K. polythalamia, in excellent condition, was dissected in 2011. (They've been studying them since.) She was recording the whole thing. "It was amazing to see how powerful and alive they were," Haygood, a research professor at the University of Utah, said. "You can see Dan Distel pull out what looks like this tube, and it just keeps coming and coming because these are such large animals." Haygood said the team was initially struck by how the animal managed to feed. The end of the shell, which houses the animal's mouth, is closed—suggesting they weren't using their mouths to eat. "The answer, at the end of years of work, is that (K. polythalamia) have bacteria living inside of them that are producing their food for them," she said. "We don't know how the sulphide, the gas that presumably dissolves in the seawater, gets into the animal." The team discovered that this shipworm lives on a diet of hydrogen sulphide and carbon dioxide, Distel said. In order to do that, the K. polythalamia needs to have sulfur oxidizing chemoautotrophic (obtaining energy from inorganic chemicals) bacteria in its gills. Currently, the researchers only know about this one population of K. polythalamia, but Haygood said the shells are collected from a variety of locations in the Philippines and elsewhere in the Indo-West Pacific, suggesting there are more out there to find. And plenty of questions, too. "Do they live in mud even as juveniles or do they start out living in wood and then jump to living in the mud?" she said. "How fast do they grow? When we get one of these animals that's over a metre long, is that five years old, or 100 years old?" These researchers also want to learn more about the K. polythalamia habitat. Most animals that live in similar habitats are very small, according to Distel, nothing like a K. polythalamia, which averages about the size of a baseball bat but can grow bigger. "I'm five-foot-three and I've seen a prize specimen in a private shell collection longer than I am tall," Haygood said. According to her, this discovery has yielded decades' worth of study. Motherboard is nominated for three Webby Awards for Best Science YouTube Channel , Best Drama , Best Tech/Science Podcast . Please vote for us!


News Article | April 19, 2017
Site: www.cnet.com

While most of us would cringe at finding something that looks like an extra long bizarre black worm squirming in the mud, scientists are thrilled they finally tracked down the elusive giant shipworm -- scientifically named Kuphus polythalamia. Though it might look like a long worm, the shipworm is actually classified as a bivalve mollusk, like a clam or a mussel. The shipworm -- which measures 5 feet (155 centimeters) long and 2.3 inches (6 centimeters) in diameter -- is encased in a hard shell and lives underwater in the mud. Scientists were aware of the giant shipworm's existence for years, but no live specimen of the creature was available to study in a lab environment until now. After being spotted it in a TV program from the Philippines, five live specimens were each shipped inside PVC pipes to scientists, who filmed the unveiling of the shipworms from their hard shells as well as the dissections themselves. The scientific paper "Discovery of chemoautotrophic symbiosis in the giant shipworm Kuphus polythalamia (Bivalvia: Teredinidae) extends wooden-steps theory" published Monday in the Proceedings of the National Academy of Sciences journal, reveals the scientists' unusual findings. In addition to the mollusk's unusual black coloring on the outside, scientists were also surprised by the shipworms' unusually small internal organs. They also discovered that the creature's intestines had yellow spots from bacteria that turned hydrogen sulfide into food, which is the first time it has been observed in shipworms. "I've been studying shipworms since 1989 and in all that time I had never seen a living specimen of Kuphus polythalamia," Daniel Distel, a co-author of the new study and the director of Northeastern University's Ocean Genome Legacy Center told The Sydney Morning Herald. "It was pretty spectacular to lift that tube out of its container for the first time." Technically Incorrect: Bringing you a fresh and irreverent take on tech. Virtual reality 101: CNET tells you everything you need to know about VR.


News Article | April 18, 2017
Site: www.bbc.co.uk

Scientists have found live specimens of the rare giant shipworm for the first time, in the Philippines. Details of the creature, which can reach up to 1.55m (5ft) in length and 6cm (2.3in) in diameter, were published in a US science journal. The giant shipworm spends its life encased in a hard shell, submerged head-down in mud. Though its existence has been known for years, no living specimen had been studied until now. Despite its name, the giant shipworm is actually a bivalve - the same group as clams and mussels. The "rare and enigmatic species", also known as Kuphus polythamia, is the longest living bivalve known to man, according to the study published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). The strange shells have been found for centuries, because they are "very sturdy and they last a long time," said Daniel Distel, the report's chief author. "But we've never known where to find them." The discovery came about by chance, when Dr Distel's team was working in the Philippines with local scientists. "One of our students came in and said, 'hey, look at this' - he'd found this really great video on YouTube," Dr Distel said. "We searched the literature and the scientific sources for years, and then we find it on YouTube. It's the miracle of social media." That led a team of scientists from the US, the Philippines and France to find and collect five giant shipworms in Mindanao in a marine bay. For Dr Distel, who works at Ocean Genome Legacy - a research group and "gene bank", storing the genetic material of rare ocean creatures - it was a major find. But the scientists are keeping the exact location secret. The giant shipworms were once found all over the globe, but the team does not know how many are left. On top of that, the outside tubes "fetch a pretty good price" among shell collectors, so the researchers are being careful. A video shows the scientists cutting off one end of a shipworm's shell, before gently shaking it out. A long, slimy black creature is seen sliding out of the tube-like shell. "It was like opening a soft-boiled egg - I just tapped on it very, very lightly with a chisel, made a circle, and the shell came off, just like an egg," Dr Distel said. "It feels a lot like it looks - it's kind of slimy, but it wasn't objectionable, it didn't smell bad." The team was, however, surprised by its jet-black colour - most bivalves are light cream colours. It is also extremely muscular - or "beefy" - despite the fact that it lives its life in a shell. Previously, the best information they had was based off drawings of a poorly-preserved dead specimen from the 1960s. You might also like: The creature belongs to the shipworm family, whose members are usually much smaller. They burrow into and feed on rotting wood. The giant shipworm is unique not just for its size, but also for feeding on nutrients in mud and marine sediment instead, using a type of bacteria. It therefore has a much smaller digestive system compared to other shipworms. And while the discovery of the animal itself is exciting, the team's research has revealed there is an entire hidden ecosystem at play. The giant shipworm has bacteria that live inside its shell, converting chemicals from the nearby rotting wood into energy and nutrients, similar to what plants do with sunlight. That, Dr Distel said, will be a big part of their future research on these rare specimens.


News Article | April 17, 2017
Site: news.yahoo.com

Kuphus polythalamia lives in a baseball-bat-like shell, burrows into the mud and eats swamp gas. An international team of scientists is studying live specimens of a giant, black, mud dwelling worm-like animal — a Kuphus polythalamia — that feeds on sulfur and lives in a shell that looks like a baseball bat. People have known about giant shipworms for centuries but obtaining live ones for study has been elusive. Researchers from the University of Utah, Northeastern University, University of the Philippines, Sultan Kudarat State University and Drexel University finally found the mollusks in a lagoon on an abandoned log farm in the Philippines. Read: Immune System Can Be Reprogrammed With Them, Researchers Say The researchers hope by studying the microbes found in of the world’s longest bivalve’s single gill they will find new antimicrobial substances. For more news videos visit Yahoo View, available now on iOS and Android. The findings were published Monday in the Proceedings of the National Academy of Sciences. Unlike its slimy cousins, K.polythalamia doesn’t eat rotting wood. Rather, it burrows into the mud, consuming hydrogen sulfide. Its microbes turn the swamp gas into carbon. "This particular species fall square in the middle of the family, so we know it had to have a wood-eating ancestor," Margo Haygood, a research professor in medicinal chemistry at the University of Utah College of Pharmacy, told Popular Science. "Do they start out eating wood? We don't know anything about their life cycle, or where we might find more populations of them. And we have no idea how old they are. ... Are the specimens we studied a couple years old, or a couple hundred?" The animal’s shells, which look like elephant tusks and can be 5-feet in length, often wash ashore. The giant shipworm itself is “dark gray, shiny and floppy,” Haygood said. "I was awestruck when I first saw the sheer immensity of this bizarre animal," Marvin Altamia, a researcher at the marine sciences institute, University of the Philippines, told Phys.org. Daniel Distel of the Ocean Genome Legacy Center at Northeastern University in Boston said he and colleagues were first made aware of the colony in 2010 as the result of a Philippine TV news story on people trying to eat the slimy beasts for medicinal purposes. He told New Scientist he had been “looking for them for 20 years.” “It’s hard not to be amazed when seeing one in the flesh, even if you know nothing about them,” Distel said. “There is no other animal like them.” Distel said the giant shipworm evolved from the wood-eating variety and likely is a newer addition to the family tree.


News Article | April 18, 2017
Site: www.gizmag.com

This is the first time that scientists have found live specimens of the mud-burrowing giant shipworm (removed from its shell in this picture), which thrives on a gas toxic to most living creatures  (Credit: Marvin Altamia) Hydrogen sulfide is not a gas that is usually described as life sustaining. Even at low concentrations it smells like rotten egg and exposure to high levels can cause all kinds of health problems, such as nausea, loss of smell and even death in extreme situations. However while its toxic fumes might knock most of us out, there is a creature that thrives on this toxic gas – the giant shipworm, a mysterious mud-dwelling creature that has eluded scientists till now. Found in a lagoon laden with rotting wood in the southern Philippine island of Mindanao, the giant shipworm (Kuphus polythalamia) has been playing a game of catch-me-if-you-can with scientists since the 18th century. While its empty shells, which can measure up to five-foot long, are fairly common, the creature itself – and a live specimen at that – is not, says lead investigator Daniel Distel, a research professor and director of the Ocean Genome Legacy Center at Northeastern University. As luck would have it, scientists were handed a clue when a collaborator alerted them to a Filipino documentary on the creature (known to locals as the giant tamilok). An expedition was duly organized and live specimens were eventually found and transported to the University of the Philippines for analysis. "I was awestruck when I first saw the sheer immensity of this bizarre animal," says Marvin Altamia, a researcher at the marine sciences institute, University of the Philippines. Compared to its skinny, pale-hued wood-boring cousins, which are typically a foot long (30 cm), the ink-black giant shipworm looks like the dismembered tentacle of a larger and scarier creature, reaching lengths of 155 cm (5 ft) and making it the longest bivalve known to scientists. (Despite its name, it is actually a clam, not a worm.) Bizarre appearance aside, what sets the giant shipworm apart from its cousins is the way it sustains itself. Unlike the latter, which feed on the wood they burrow into, its digestive system is disproportionately tiny compared to the rest of its body. As the researchers discovered, the giant shipworm does not have the large sac-like cecum, found in all other members of the same bivalve family, which stores digested wood particles. In addition, only trace quantities of fecal matter were found in its digestive system, which rules out the possibility that its much bigger size is due to ingestion of wood, even though it was found in a place with plenty of wood debris. Furthermore, it lives enclosed in its shell, which has a cap that covers its mouth, thus ruling out the possibility that it excavates and feeds on the sediments in the mud, like earthworms. So if it doesn't eat wood or mud, how did it become so much larger than other shipworms? The answer to this mystery lies in its outsized gill (see illustration below), within which live bacteria. While this in itself is not unusual - normal shipworms also have bacteria living in their gill that help them digest the wood they eat - what the researchers found when studying the giant shipworm was that its bacterial genome contains features, such as sulfur globules, similar to those in other sulfur-oxidizing bacteria. This led them to surmise that that the creature gets its energy from the carbon the bacteria produce when they break down the hydrogen sulfide in its habitat. And since the giant shipworm doesn't have to use its digestive organs at all, this would also explain the size of the organs. Back in 2000, Distel published a study proposing the theory that mussels found living in deep sea vents had evolved from specimens commonly found on sunken whale bones and rotting wood. This transition was made possible by the sulfur-oxidizing bacteria they harbored, which enabled them to survive on the gas produced by the vents when they sank to the ocean floor. Similarly, the researchers believe that the giant shipworm evolved from wood-eating ancestors that used wood as a "stepping stone" between habitats. Eventually, they evolved when they traded the wood-processing bacteria in their gills for the sulfur-ingesting variety, thus allowing them to thrive on the toxic gas, of which there is no shortage given the abundance of rotting wood and organic matter in these marine environments. Apart from giving them a complete makeover in the size and anatomy departments, the researchers also believe that this evolutionary transition led to "a fundamental change" in the relationship between the shipworms and sulfur-oxidizing bacteria. In wood-eating shipworms, the bacteria acquire organic carbon from the host and in return provide digestive enzymes that help it to process the wood it eats, note the authors in their study. In the case of the giant shipworm, the bacteria require no organic carbon from the host, but instead provide it with the carbon they produce. "We suspected the giant shipworm was radically different from other wood-eating shipworms," says senior author Margo Haygood, a research professor in medicinal chemistry at the University of Utah. "Finding the animal confirmed that." You can watch the researchers remove the giant shipworm from its shell in the video below – if you dare. The study was published in the Proceedings of the National Academy of Sciences.


Our world seems to grow smaller by the day as biodiversity rapidly dwindles, but Mother Earth still has a surprise or two up her sleeve. An international team of researchers were the first to investigate a never before studied species -- a giant, black, mud dwelling, worm-like animal. The odd animal doesn't seem to eat much, instead it gets its energy from a form of sulfur. The findings, led by scientists at the University of Utah, Northeastern University, University of the Philippines, Sultan Kudarat State University and Drexel University, will be published online in the Apr. 17 issue of the Proceedings of the National Academy of Sciences. People have known about the existence of the creature for centuries. The three- to five-foot long, tusk-like shells that encase the animal were first documented in the 18th century. "The shells are fairly common," begins lead investigator Daniel Distel, Ph.D., a research professor and director of the Ocean Genome Legacy Center at Northeastern University, "But we have never had access to the animal living inside." The animal's preferred habitat was unclear, but the research team benefitted from a bit of serendipity when one of their collaborators shared a documentary that aired on Philippine television. The video showed the bizarre creatures planted, like carrots, in the mud of a shallow lagoon. Following this lead, the scientists set up an expedition and found live specimens of Kuphus polythalamia. With a live giant shipworm finally in hand, the research team huddled around Distel as he carefully washed the sticky mud caked to the outside of the giant shipworm shell and tapped off the outer cap, revealing the creature living inside. "I was awestruck when I first saw the sheer immensity of this bizarre animal," says Marvin Altamia, researcher at the marine sciences institute, University of the Philippines. "Being present for the first encounter of an animal like this is the closest I will ever get to being a 19th century naturalist," says the study's senior author Margo Haygood, a research professor in medicinal chemistry at the University of Utah College of Pharmacy. Because the animal had never been studied rigorously, little was known about its life history, habitat, or biology. "We suspected the giant shipworm was radically different from other wood-eating shipworms," says Haygood. "Finding the animal confirmed that." Altamia continues, "Frankly, I was nervous. If we made a mistake, we could lose the opportunity to discover the secrets of this very rare specimen." The scientists were then faced with an interesting dilemma explain why Kuphus is so unusual. The answer may lie in the remote habitat in which it was found, a lagoon laden with rotting wood. The normal shipworm burrows deep into the wood of trees that have washed into the ocean, munching on and digesting the wood with the help of bacteria. Unlike its shipworm cousins, Kuphus lives in the mud. It also turns to bacteria to obtain nourishment, but in a different way. Kuphus lives in a pretty stinky place. The organic-rich mud around its habitat emits hydrogen sulfide, a gas derived from sulfur, which has a distinct rotten egg odor. This environment may be noxious for you and me, but it is a feast for the giant shipworm. And yet Kuphus themselves don't eat, or if they do, they eat very little. Instead, they rely on beneficial bacteria that live in their gills that make food for them. Like tiny chefs, these bacteria use the hydrogen sulfide as energy to produce organic carbon that feeds the shipworm. This process is similar to the way green plants use the sun's energy to convert carbon dioxide in the air into simple carbon compounds during photosynthesis. As a result, many of Kuphus's internal digestive organs have shrunk from lack of use. The giant shipworm's lifestyle lends support to a hypothesis proposed by Distel almost two decades ago. Acquiring a different type of beneficial bacteria could explain how shipworms transition from a wood-eating organism to one that uses a noxious gas in mud to survive. The research team will continue to examine the role wood plays in the unique transition between the normal shipworm and the giant shipworm. "We are also interested to see if similar transitions can be found for other animals that live in unique habitats around the world," said Distel. The discovery of this flagship creature expands on our understanding of biodiversity in the Indo-Pacific region, which was made possible through collaborative nature of this interdisciplinary, international research group. This work is an important component of research grants provided by the International Cooperative Biodiversity Groups program. The program helps researchers conduct projects in developing countries to identify unique, novel compounds for future drug development, while building research capacity and conserving biodiversity in the host country. Distel and Haygood collaborated with colleagues from University of Utah, Drexel University, Second Genome in San Francisco, Ecole Normale Superieure, France and the University of the Philippines, the Sultan Kudarat State University and the Philippine Genome Center in the Philippines. The research was funded by National Institutes of Health, National Science Foundation and U.S Department of Energy, Joint Genome Institute.


News Article | April 25, 2017
Site: www.eurekalert.org

Northeastern professor Daniel Distel and his colleagues have discovered a dark slithering creature four feet long that dwells in the foul mud of a remote lagoon in the Philippines. They say studying the animal, a giant shipworm with pinkish siphons at one end and an eyeless head at the other, could add to our understanding of how bacteria cause infections and, in turn, how we might adapt to tolerate--and even benefit from--them. Live specimens of the massive shipworm, which was captured by Distel's team with the help of researchers from the area, have eluded scientific description for hundreds of years. Distel, research professor at Northeastern's Marine Science Center, has been searching for it for two decades. He had examined fragments of its tusk-like shell, made of calcium carbonate, and gazed wistfully at dead specimens preserved in ethanol. But neither he, nor any other living researchers, had ever come across a live specimen of the ancient species, a bivalve mollusc named Kuphus polythalamia that was first described (though incorrectly classified) by Swedish taxonomist Carl Linnaeus in 1758. Now, in a new paper published in the Proceedings of the National Academy of Sciences, Distel and his colleagues present their research on the live shipworm. They describe how, remarkably, it does not eat, at least not much--it has a tiny digestive system--but instead bacteria living inside its gills convert sulfur gas from rotting wood into nutrients to keep it alive. "Most shipworms are very delicate, translucent, usually white, beige or pink," says Distel, who directs the Ocean Genome Legacy at Northeastern, a unique biological bank where researchers acquire DNA from organisms around the world for genetic analysis. "They're mostly small, a few centimeters long. You have to be very careful not to damage them when you're taking them out of the wood, where they live. This thing was like a baseball bat. It was a beefy, muscular animal, jet black." Indeed, the team had to edit much of the audio out of the original video of the creature's debut. "When I took that thing out of the tube there was a collective gasp among the whole group," says Distel, "along with quite a number of expletives that had to be deleted." Distel's genomic analysis of the host Kuphus as well as the bacteria whipping up its food revealed a symbiotic relationship between the two that elucidates an "evolutionary stepping stone," he says. Shipworms as a rule eat wood; hence their being dubbed "termites of the sea." Bacteria in their gills, Distel discovered earlier, secrete enzymes that travel to their gut and break down the wood--which is made of cellulose, an organic material--turning it into sugars. But wood can also serve as a source of hydrogen sulfide--a sulfur gas that smells like rotten eggs. "We believe that somewhere along the line a shipworm acquired a sulfur-oxidizing bacteria as a symbiont, and it was able to get energy not just from the wood but also from the inorganic gas hydrogen sulfide coming from the wood as it rotted," says Distel. "Eventually the new symbiosis completely replaced the old symbiosis." Other marine animals also get their nutrients from sulfur-oxidizing symbionts, but the sulfur source differs: The giant tubeworm Riftia pachyptila, for example, gets its sulfur from the effluence of volcanic hot springs on the sea floor. The symbiont bacteria convert the hydrogen sulfide into food similar to the way photosynthesis works in green plants. Green plants take energy from sunlight and use it to synthesize sugars from carbon dioxide. The bacteria take chemical energy from hydrogen sulfide, pull carbon dioxide out of the seawater, and synthesize sugars and other nutrients. "These bacteria live inside the animals' cells, alongside the cytoplasm," says Distel. "If we or any vertebrate had bacteria living inside our cells, we'd be very sick. In the long run, studying these symbioses may tell us a lot about the process of disease. What is it about these bacteria that they can infect the host yet not harm it? How does the host learn to tolerate, and even benefit from, the bacteria?" "For a biologist who is interested in these bivalves, it's like a unicorn," said Margo Haygood, a marine microbiologist at the University of Utah and senior author on the study, in a video revealing one of the giant shipworms. Distel praises the power of social media for helping the researchers finally find the elusive giant. They were in the Philippines in 2010 as part of a National Institutes of Health-funded project called the Philippine Mollusc Symbiont-International Cooperative Biodiversity Groups, studying molluscs and symbiotic bacteria in search of natural compounds that might be developed into antibiotics and other drugs. A student researcher reported seeing a YouTube documentary showing people on the island of Mindanao eating the shipworms, a delicacy, known in the area as Tamilok, that some believe has medicinal properties. By the time the live creatures--packed in an odiferous brew of mud and seawater inside PVC pipes--arrived on the dissecting table at the University of the Philippines Manila, Distel's head was spinning. "I was excited, amazed, and then concerned," he says about seeing the animal slip out of its shell tubing after he'd cracked open one end. "What samples do we need to take? What tissues do we freeze? What tissues do we preserve in ethanol? What tissues do we preserve for electron microscopy? How do we preserve things for DNA studies? Remember, we didn't know what we were going to get so we couldn't fully prepare. Once we started cutting, amazement was gone and it was down to work, trying to figure out, 'How do we not screw this up?'"


News Article | April 26, 2017
Site: www.sciencedaily.com

Northeastern professor Daniel Distel and his colleagues have discovered a dark slithering creature four feet long that dwells in the foul mud of a remote lagoon in the Philippines. They say studying the animal, a giant shipworm with pinkish siphons at one end and an eyeless head at the other, could add to our understanding of how bacteria cause infections and, in turn, how we might adapt to tolerate -- and even benefit from -- them. Live specimens of the massive shipworm, which was captured by Distel's team with the help of researchers from the area, have eluded scientific description for hundreds of years. Distel, research professor at Northeastern's Marine Science Center, has been searching for it for two decades. He had examined fragments of its tusk-like shell, made of calcium carbonate, and gazed wistfully at dead specimens preserved in ethanol. But neither he, nor any other living researchers, had ever come across a live specimen of the ancient species, a bivalve mollusc named Kuphus polythalamia that was first described (though incorrectly classified) by Swedish taxonomist Carl Linnaeus in 1758. Now, in a new paper published in the Proceedings of the National Academy of Sciences, Distel and his colleagues present their research on the live shipworm. They describe how, remarkably, it does not eat, at least not much -- it has a tiny digestive system -- but instead bacteria living inside its gills convert sulfur gas from rotting wood into nutrients to keep it alive. "Most shipworms are very delicate, translucent, usually white, beige or pink," says Distel, who directs the Ocean Genome Legacy at Northeastern, a unique biological bank where researchers acquire DNA from organisms around the world for genetic analysis. "They're mostly small, a few centimeters long. You have to be very careful not to damage them when you're taking them out of the wood, where they live. This thing was like a baseball bat. It was a beefy, muscular animal, jet black." Indeed, the team had to edit much of the audio out of the original video of the creature's debut. "When I took that thing out of the tube there was a collective gasp among the whole group," says Distel, "along with quite a number of expletives that had to be deleted." Distel's genomic analysis of the host Kuphus as well as the bacteria whipping up its food revealed a symbiotic relationship between the two that elucidates an "evolutionary stepping stone," he says. Shipworms as a rule eat wood; hence their being dubbed "termites of the sea." Bacteria in their gills, Distel discovered earlier, secrete enzymes that travel to their gut and break down the wood -- which is made of cellulose, an organic material -- turning it into sugars. But wood can also serve as a source of hydrogen sulfide -- a sulfur gas that smells like rotten eggs. "We believe that somewhere along the line a shipworm acquired a sulfur-oxidizing bacteria as a symbiont, and it was able to get energy not just from the wood but also from the inorganic gas hydrogen sulfide coming from the wood as it rotted," says Distel. "Eventually the new symbiosis completely replaced the old symbiosis." Other marine animals also get their nutrients from sulfur-oxidizing symbionts, but the sulfur source differs: The giant tubeworm Riftia pachyptila, for example, gets its sulfur from the effluence of volcanic hot springs on the sea floor. The symbiont bacteria convert the hydrogen sulfide into food similar to the way photosynthesis works in green plants. Green plants take energy from sunlight and use it to synthesize sugars from carbon dioxide. The bacteria take chemical energy from hydrogen sulfide, pull carbon dioxide out of the seawater, and synthesize sugars and other nutrients. "These bacteria live inside the animals' cells, alongside the cytoplasm," says Distel. "If we or any vertebrate had bacteria living inside our cells, we'd be very sick. In the long run, studying these symbioses may tell us a lot about the process of disease. What is it about these bacteria that they can infect the host yet not harm it? How does the host learn to tolerate, and even benefit from, the bacteria?" "For a biologist who is interested in these bivalves, it's like a unicorn," said Margo Haygood, a marine microbiologist at the University of Utah and senior author on the study, in a video revealing one of the giant shipworms. Distel praises the power of social media for helping the researchers finally find the elusive giant. They were in the Philippines in 2010 as part of a National Institutes of Health-funded project called the Philippine Mollusc Symbiont-International Cooperative Biodiversity Groups, studying molluscs and symbiotic bacteria in search of natural compounds that might be developed into antibiotics and other drugs. A student researcher reported seeing a YouTube documentary showing people on the island of Mindanao eating the shipworms, a delicacy, known in the area as Tamilok, that some believe has medicinal properties. By the time the live creatures -- packed in an odiferous brew of mud and seawater inside PVC pipes -- arrived on the dissecting table at the University of the Philippines Manila, Distel's head was spinning. "I was excited, amazed, and then concerned," he says about seeing the animal slip out of its shell tubing after he'd cracked open one end. "What samples do we need to take? What tissues do we freeze? What tissues do we preserve in ethanol? What tissues do we preserve for electron microscopy? How do we preserve things for DNA studies? Remember, we didn't know what we were going to get so we couldn't fully prepare. Once we started cutting, amazement was gone and it was down to work, trying to figure out, 'How do we not screw this up?'"


Distel D.L.,Ocean Genome Legacy Inc. | Amin M.,University of Maine, United States | Burgoyne A.,University of Maine, United States | Linton E.,Central Michigan University | And 5 more authors.
Molecular Phylogenetics and Evolution | Year: 2011

The ability to consume wood as food (xylotrophy) is unusual among animals. In terrestrial environments, termites and other xylotrophic insects are the principle wood consumers while in marine environments wood-boring bivalves fulfill this role. However, the evolutionary origin of wood feeding in bivalves has remained largely unexplored. Here we provide data indicating that xylotrophy has arisen just once in Bivalvia in a single wood-feeding bivalve lineage that subsequently diversified into distinct shallow- and deep-water branches, both of which have been broadly successful in colonizing the world's oceans. These data also suggest that the appearance of this remarkable life habit was approximately coincident with the acquisition of bacterial endosymbionts. Here we generate a robust phylogeny for xylotrophic bivalves and related species based on sequences of small and large subunit nuclear rRNA genes. We then trace the distribution among the modern taxa of morphological characters and character states associated with xylotrophy and xylotrepesis (wood-boring) and use a parsimony-based method to infer their ancestral states. Based on these ancestral state reconstructions we propose a set of plausible hypotheses describing the evolution of symbiotic xylotrophy in Bivalvia. Within this context, we reinterpret one of the most remarkable progressions in bivalve evolution, the transformation of the " typical" myoid body plan to create a unique lineage of worm-like, tube-forming, wood-feeding clams. The well-supported phylogeny presented here is inconsistent with most taxonomic treatments for xylotrophic bivalves, indicating that the bivalve family Pholadidae and the subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic, and that the principle traits used for their taxonomic diagnosis are phylogenetically misleading. © 2011 Elsevier Inc.


Altamia M.A.,University of the Philippines at Diliman | Wood N.,Ocean Genome Legacy Inc. | Fung J.M.,Ocean Genome Legacy Inc. | Dedrick S.,Ocean Genome Legacy Inc. | And 4 more authors.
Molecular Ecology | Year: 2014

Teredinibacter turnerae is a cultivable intracellular endosymbiont of xylotrophic (wood-feeding) bivalves of the Family Teredinidae (shipworms). Although T. turnerae has been isolated from many shipworm taxa collected in many locations, no systematic effort has been made to explore genetic diversity within this symbiont species across the taxonomic and geographical range of its hosts. The mode of symbiont transmission is unknown. Here, we examine sequence diversity in fragments of six genes (16S rRNA, gyrB, sseA, recA, rpoB and celAB) among 25 isolates of T. turnerae cultured from 13 shipworm species collected in 15 locations in the Atlantic, Pacific and Indian Oceans. While 16S rRNA sequences are nearly invariant between all examined isolates (maximum pairwise difference <0.26%), variation between examined protein-coding loci is greater (mean pairwise difference 2.2-5.9%). Phylogenetic analyses based on each protein-coding locus differentiate the 25 isolates into two distinct and well-supported clades. With five exceptions, clade assignments for each isolate were supported by analysis of alleles of each of the five protein-coding loci. These exceptions include (i) putative recombinant alleles of the celAB and gyrB loci in two isolates (PMS-535T.S.1b.3 and T8510), suggesting homologous recombination between members of the two clades; and (ii) evidence for a putative lateral gene transfer event affecting a second locus (recA) in three isolates (T8412, T8503 and T8513). These results demonstrate that T. turnerae isolates do not represent a homogeneous global population. Instead, they indicate the emergence of two lineages that, although distinct, likely experience some level of genetic exchange with each other and with other bacterial species. © 2014 John Wiley & Sons Ltd.

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