Feb 7, 2016 06:26 PM
Many white-tailed deer have malaria: First-ever native malaria in the Americas
http://www.sciencedaily.com/releases/201...153323.htm
RELEASE: Two years ago, Ellen Martinsen, was collecting mosquitoes at the Smithsonian's National Zoo, looking for malaria that might infect birds--when she discovered something strange: a DNA profile, from parasites in the mosquitoes, that she couldn't identify.
By chance, she had discovered a malaria parasite, Plasmodium odocoilei--that infects white-tailed deer. It's the first-ever malaria parasite known to live in a deer species and the only native malaria parasite found in any mammal in North or South America. Though white-tailed deer diseases have been heavily studied--scientist hadn't noticed that many have malaria parasites.
Martinsen and her colleagues estimate that the parasite infects up to twenty-five percent of white-tailed deer along the East Coast of the United States. Their results were published February 5 in Science Advances.
In hiding
"You never know what you're going to find when you're out in nature--and you look," says Martinsen, a research associate at the Smithsonian's Conservation Biology Institute and adjunct faculty in the University of Vermont's biology department. "It's a parasite that has been hidden in the most iconic game animal in the United States. I just stumbled across it."
The new study, led by Martinsen, was a collaboration with scientists at the Smithsonian Conservation Biology Institute, the American Museum of Natural History, the National Park Service, the University of Georgia, the University of Wisconsin-Milwaukee--and UVM biologist and malaria expert Joseph Schall.
Though Martinsen and Schall are quick to note that they anticipate little danger to people from this newly discovered deer malaria, it does underline the fact that many human health concerns are connected to wider ecological systems--and that understanding the biology of other species is a foundation to both conservation and public health management. Zika virus is recently making worrisome headlines and "there's a sudden surge in interest in mosquito biology across the United States," says Schall. "This is a reminder of the importance of parasite surveys and basic natural history."
In 1967, a renowned malaria researcher reported he'd discovered malaria in a single deer in Texas. But the received understanding was that "malaria wasn't supposed to be in mammals in the New World," says Schall, who has studied malaria for decades. "It was like the guy was reporting he saw Big Foot," and no other discoveries were made after that.
But now Martinsen and her colleagues have discovered that the deer malaria is widespread--though it's "cryptic" she says, because the parasites occur in very low levels in many of the infected deer. "Ellen spent days and days looking through a microscope at slides that were mostly empty," Schall says, but eventually found the parasites. Combined with sensitive molecular PCR techniques to understand the genetics, the team confirmed a high prevalence of the disease--between eighteen and twenty-five percent--in sites ranging from New York to West Virginia to Louisiana.
Native species
The new discovery fundamentally changes our understanding of the distribution and evolutionary history of malaria parasites in mammals, Martinsen says. Some scientists wondered if the deer malaria could have jumped from people or zoo animals in the recent past. But the new study suggests otherwise. The team's data shows that the deer actually carry two genetic lineages of the malaria parasites--"probably different species," she says--and that the two lineages are substantially different from each other.
This divergence between the two forms of malaria was used by the scientists as a kind of molecular clock. "We can date the evolutionary split between those two lineages," Martinsen says--to 2.3 to 6 million years ago. Which probably means that when the ancient evolutionary ancestors to white-tailed deer traveled from Eurasia across the Bering Land Bridge to North America in the Miocene, some 4.2 to 5.7 million years ago--malaria came along for the ride. "We think malaria is native to the Americas," Martinsen says, "that it's been here for millions of years."
Malaria is a major problem for people in many parts of the world--and for many species of wildlife too. It has been devastating bird species in Hawaii and Bermuda, among many epidemics. Whether it is hurting white-tailed deer in America is an open question. Martinsen suspects not, because she'd expect to see more obviously sick animals. But Schall wonders if, like some human malaria infections, the disease causes a low-level burden that hurts deer populations. They both agree that it is an area that calls for more research--and that the new study raises many other questions, including whether the parasite might infect dairy cows or other hoofed species.
Ellen Martinsen completed her undergraduate and doctoral training at UVM in Joe Schall's lab and went on to do her postdoctoral research at the Smithonian Conservation Biology Institute's Center for Conservation Genetics. The new discovery drew on a team of scientists and veterinarians at the Smithsonian and other institutions, who studied samples from both live and necropsied deer as well as mosquitoes. Additionally, Martinsen returned to Schall's lab for some of the new research.
"Malaria is a top parasitic disease in humans and wildlife," Ellen Martinsen says. "It's important that we gain a better understanding of its diversity and distribution not just across humans but across other species too."
Prehistoric mystery meat put to the test (spoiler alert: It’s not woolly mammoth or giant ground sloth)
http://www.sciencedaily.com/releases/201...153546.htm
RELEASE: Sorry, Explorers Club, but woolly mammoth is no longer on the menu. Neither is the giant ground sloth.
A Yale-led analysis has shown that a famous morsel of meat from a 1951 Explorers Club dinner is not, in fact, a hunk of woolly mammoth. It is green sea turtle meat, most likely set aside from the soup course.
At issue is the taxonomic provenance of a fist-sized piece of animal flesh prepared for an Explorers Club shindig in New York City. The event, held Jan. 13, 1951 in the Grand Ballroom of the Roosevelt Hotel, featured a dinner of Pacific spider crabs, green turtle soup, bison steaks, and portions of a 250,000-year-old woolly mammoth that had been preserved in glacial ice. At least, that's the menu that entered popular lore. Others in attendance at the dinner thought the main entrée was meat from an extinct giant ground sloth.
"I'm sure people wanted to believe it. They had no idea that many years later, a Ph.D. student would come along and figure this out with DNA sequencing techniques," said Jessica Glass, a Yale graduate student in ecology and evolutionary biology, and co-lead author of a study published Feb. 3 in the journal PLOS ONE.
"To me, this was a joke that no one got," said Matt Davis, a Yale graduate student in geology and geophysics, who is the other co-lead author of the study. "It's like a Halloween party where you put your hand in spaghetti, but they tell you it's brains. In this case, everyone actually believed it."
Reports at the time said the Reverend Bernard Hubbard, a much publicized Alaskan explorer and lecturer known as the "Glacier Priest," had supplied the mammoth meat for the banquet. The frozen beast allegedly had been found at "Woolly Cove" on Akutan Island, in the Aleutians, and shipped to New York by U.S. Navy Captain George Francis Kosco.
The banquet's promoter, Commander Wendell Phillips Dodge, was a noted impresario and former agent for film star Mae West. He sent out press notices saying the annual dinner would feature "prehistoric meat." Some attendees took this to mean woolly mammoth meat, while others believed they were being served meat from the giant ground sloth known as Megatherium. This was scientifically important, because although sloths extended into Alaska, Megatherium's range was thought to be restricted to South America.
A club member unable to attend the dinner, Paul Griswold Howes of the Bruce Museum in Greenwich, Conn., requested that a piece of meat be saved for him to display at the museum. Dodge personally filled out the specimen label for the fibrous chunk of muscle, saying it was Megatherium.
Yet over the years, the idea persisted that woolly mammoth had been served. The notion fit neatly with other stories in popular culture that imagined prehistoric mammoths found in blocks of glacial ice. That image remains iconic even today.
But science shows otherwise. Preserved mammoths would be found, not in ice, but in the frozen dirt of permafrost. "The meat wouldn't taste good, but you could eat it," Davis said.
This particular specimen, labeled as giant sloth meat, remained in the Bruce Museum until 2001, when it became part of the mammal collection at the Yale Peabody Museum of Natural History.
Eric Sargis, a Yale anthropology professor and curator of mammalogy at the Peabody, and a co-author of the study, grew increasingly curious about the sample. In 2014, Sargis found two students, Glass and Davis, who were interested in pursuing the true origins of the Explorers Club specimen.
Glass led the DNA analysis, and Davis conducted archival research. Both are members of the Explorers Club, which gave the Yale team access to its archives and provided a grant to support the study.
Adalgisa Caccone, a senior research scientist in the Department of Ecology and Evolutionary Biology and a co-author of the study, helped guide the DNA analysis at Yale's Institute for Biospheric Studies, Center for Genetic Analyses of Biodiversity. "This was an interesting challenge, in part because the meat had been cooked," Caccone said. "This was the first time I looked at the DNA of leftovers -- very precious leftovers."
Glass was able to extract DNA, purify it and conduct mitochondrial gene sequencing. The results matched the genetic profile for green sea turtle.
Meanwhile, Davis found an item in the Explorers Club archives that pointed in the same direction. It was a published statement from Dodge soon after the banquet, joking that he may have discovered a "potion" that turns green sea turtle into giant sloth meat.
Beyond solving the origins of the Explorers Club entrée, the researchers said their study illustrates the value of interdisciplinary collaboration and the ability of modern science to use museum collections in new ways. Specimens can yield more answers than ever before, noted the researchers, making their preservation critical -- even if they came out of a banquet hall kitchen.
"If this had not been from the banquet, we would still want to know the identity of the meat, because it would have large scientific implications," Davis said.
Glass noted that this year's Explorers Club banquet will be in March, but she's unable to attend. "Maybe someone will save a piece of meat for me," she said.
In addition to the Yale researchers, Timothy Walsh of the Bruce Museum was a co-author of the study.
http://www.sciencedaily.com/releases/201...153323.htm
RELEASE: Two years ago, Ellen Martinsen, was collecting mosquitoes at the Smithsonian's National Zoo, looking for malaria that might infect birds--when she discovered something strange: a DNA profile, from parasites in the mosquitoes, that she couldn't identify.
By chance, she had discovered a malaria parasite, Plasmodium odocoilei--that infects white-tailed deer. It's the first-ever malaria parasite known to live in a deer species and the only native malaria parasite found in any mammal in North or South America. Though white-tailed deer diseases have been heavily studied--scientist hadn't noticed that many have malaria parasites.
Martinsen and her colleagues estimate that the parasite infects up to twenty-five percent of white-tailed deer along the East Coast of the United States. Their results were published February 5 in Science Advances.
In hiding
"You never know what you're going to find when you're out in nature--and you look," says Martinsen, a research associate at the Smithsonian's Conservation Biology Institute and adjunct faculty in the University of Vermont's biology department. "It's a parasite that has been hidden in the most iconic game animal in the United States. I just stumbled across it."
The new study, led by Martinsen, was a collaboration with scientists at the Smithsonian Conservation Biology Institute, the American Museum of Natural History, the National Park Service, the University of Georgia, the University of Wisconsin-Milwaukee--and UVM biologist and malaria expert Joseph Schall.
Though Martinsen and Schall are quick to note that they anticipate little danger to people from this newly discovered deer malaria, it does underline the fact that many human health concerns are connected to wider ecological systems--and that understanding the biology of other species is a foundation to both conservation and public health management. Zika virus is recently making worrisome headlines and "there's a sudden surge in interest in mosquito biology across the United States," says Schall. "This is a reminder of the importance of parasite surveys and basic natural history."
In 1967, a renowned malaria researcher reported he'd discovered malaria in a single deer in Texas. But the received understanding was that "malaria wasn't supposed to be in mammals in the New World," says Schall, who has studied malaria for decades. "It was like the guy was reporting he saw Big Foot," and no other discoveries were made after that.
But now Martinsen and her colleagues have discovered that the deer malaria is widespread--though it's "cryptic" she says, because the parasites occur in very low levels in many of the infected deer. "Ellen spent days and days looking through a microscope at slides that were mostly empty," Schall says, but eventually found the parasites. Combined with sensitive molecular PCR techniques to understand the genetics, the team confirmed a high prevalence of the disease--between eighteen and twenty-five percent--in sites ranging from New York to West Virginia to Louisiana.
Native species
The new discovery fundamentally changes our understanding of the distribution and evolutionary history of malaria parasites in mammals, Martinsen says. Some scientists wondered if the deer malaria could have jumped from people or zoo animals in the recent past. But the new study suggests otherwise. The team's data shows that the deer actually carry two genetic lineages of the malaria parasites--"probably different species," she says--and that the two lineages are substantially different from each other.
This divergence between the two forms of malaria was used by the scientists as a kind of molecular clock. "We can date the evolutionary split between those two lineages," Martinsen says--to 2.3 to 6 million years ago. Which probably means that when the ancient evolutionary ancestors to white-tailed deer traveled from Eurasia across the Bering Land Bridge to North America in the Miocene, some 4.2 to 5.7 million years ago--malaria came along for the ride. "We think malaria is native to the Americas," Martinsen says, "that it's been here for millions of years."
Malaria is a major problem for people in many parts of the world--and for many species of wildlife too. It has been devastating bird species in Hawaii and Bermuda, among many epidemics. Whether it is hurting white-tailed deer in America is an open question. Martinsen suspects not, because she'd expect to see more obviously sick animals. But Schall wonders if, like some human malaria infections, the disease causes a low-level burden that hurts deer populations. They both agree that it is an area that calls for more research--and that the new study raises many other questions, including whether the parasite might infect dairy cows or other hoofed species.
Ellen Martinsen completed her undergraduate and doctoral training at UVM in Joe Schall's lab and went on to do her postdoctoral research at the Smithonian Conservation Biology Institute's Center for Conservation Genetics. The new discovery drew on a team of scientists and veterinarians at the Smithsonian and other institutions, who studied samples from both live and necropsied deer as well as mosquitoes. Additionally, Martinsen returned to Schall's lab for some of the new research.
"Malaria is a top parasitic disease in humans and wildlife," Ellen Martinsen says. "It's important that we gain a better understanding of its diversity and distribution not just across humans but across other species too."
Prehistoric mystery meat put to the test (spoiler alert: It’s not woolly mammoth or giant ground sloth)
http://www.sciencedaily.com/releases/201...153546.htm
RELEASE: Sorry, Explorers Club, but woolly mammoth is no longer on the menu. Neither is the giant ground sloth.
A Yale-led analysis has shown that a famous morsel of meat from a 1951 Explorers Club dinner is not, in fact, a hunk of woolly mammoth. It is green sea turtle meat, most likely set aside from the soup course.
At issue is the taxonomic provenance of a fist-sized piece of animal flesh prepared for an Explorers Club shindig in New York City. The event, held Jan. 13, 1951 in the Grand Ballroom of the Roosevelt Hotel, featured a dinner of Pacific spider crabs, green turtle soup, bison steaks, and portions of a 250,000-year-old woolly mammoth that had been preserved in glacial ice. At least, that's the menu that entered popular lore. Others in attendance at the dinner thought the main entrée was meat from an extinct giant ground sloth.
"I'm sure people wanted to believe it. They had no idea that many years later, a Ph.D. student would come along and figure this out with DNA sequencing techniques," said Jessica Glass, a Yale graduate student in ecology and evolutionary biology, and co-lead author of a study published Feb. 3 in the journal PLOS ONE.
"To me, this was a joke that no one got," said Matt Davis, a Yale graduate student in geology and geophysics, who is the other co-lead author of the study. "It's like a Halloween party where you put your hand in spaghetti, but they tell you it's brains. In this case, everyone actually believed it."
Reports at the time said the Reverend Bernard Hubbard, a much publicized Alaskan explorer and lecturer known as the "Glacier Priest," had supplied the mammoth meat for the banquet. The frozen beast allegedly had been found at "Woolly Cove" on Akutan Island, in the Aleutians, and shipped to New York by U.S. Navy Captain George Francis Kosco.
The banquet's promoter, Commander Wendell Phillips Dodge, was a noted impresario and former agent for film star Mae West. He sent out press notices saying the annual dinner would feature "prehistoric meat." Some attendees took this to mean woolly mammoth meat, while others believed they were being served meat from the giant ground sloth known as Megatherium. This was scientifically important, because although sloths extended into Alaska, Megatherium's range was thought to be restricted to South America.
A club member unable to attend the dinner, Paul Griswold Howes of the Bruce Museum in Greenwich, Conn., requested that a piece of meat be saved for him to display at the museum. Dodge personally filled out the specimen label for the fibrous chunk of muscle, saying it was Megatherium.
Yet over the years, the idea persisted that woolly mammoth had been served. The notion fit neatly with other stories in popular culture that imagined prehistoric mammoths found in blocks of glacial ice. That image remains iconic even today.
But science shows otherwise. Preserved mammoths would be found, not in ice, but in the frozen dirt of permafrost. "The meat wouldn't taste good, but you could eat it," Davis said.
This particular specimen, labeled as giant sloth meat, remained in the Bruce Museum until 2001, when it became part of the mammal collection at the Yale Peabody Museum of Natural History.
Eric Sargis, a Yale anthropology professor and curator of mammalogy at the Peabody, and a co-author of the study, grew increasingly curious about the sample. In 2014, Sargis found two students, Glass and Davis, who were interested in pursuing the true origins of the Explorers Club specimen.
Glass led the DNA analysis, and Davis conducted archival research. Both are members of the Explorers Club, which gave the Yale team access to its archives and provided a grant to support the study.
Adalgisa Caccone, a senior research scientist in the Department of Ecology and Evolutionary Biology and a co-author of the study, helped guide the DNA analysis at Yale's Institute for Biospheric Studies, Center for Genetic Analyses of Biodiversity. "This was an interesting challenge, in part because the meat had been cooked," Caccone said. "This was the first time I looked at the DNA of leftovers -- very precious leftovers."
Glass was able to extract DNA, purify it and conduct mitochondrial gene sequencing. The results matched the genetic profile for green sea turtle.
Meanwhile, Davis found an item in the Explorers Club archives that pointed in the same direction. It was a published statement from Dodge soon after the banquet, joking that he may have discovered a "potion" that turns green sea turtle into giant sloth meat.
Beyond solving the origins of the Explorers Club entrée, the researchers said their study illustrates the value of interdisciplinary collaboration and the ability of modern science to use museum collections in new ways. Specimens can yield more answers than ever before, noted the researchers, making their preservation critical -- even if they came out of a banquet hall kitchen.
"If this had not been from the banquet, we would still want to know the identity of the meat, because it would have large scientific implications," Davis said.
Glass noted that this year's Explorers Club banquet will be in March, but she's unable to attend. "Maybe someone will save a piece of meat for me," she said.
In addition to the Yale researchers, Timothy Walsh of the Bruce Museum was a co-author of the study.