PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Scientists offer first definitive proof of bacteria-feeding behavior in green algae

Study gives look at early evolutionary event that paved way for land plants, animals

2013-05-24
(Press-News.org) A team of researchers has captured images of green alga consuming bacteria, offering a glimpse at how early organisms dating back more than 1 billion years may have acquired free-living photosynthetic cells. This acquisition is thought to have been a critical first step in the evolution of photosynthetic algae and land plants, which, in turn, contributed to the increase in oxygen levels in Earth's atmosphere and ocean and provided one of the conditions necessary for animal evolution.

In a paper that appears in the June 17 issue of Current Biology and is available online today, researchers identify a mechanism by which a green alga that resembles early ancestors of the group engulfs bacteria, providing conclusive evidence for a process that had been proposed but not definitely shown.

"This behavior had previously been suggested but we had not had clear microscopic evidence until this study," said Eunsoo Kim, assistant curator in the Museum's Division of Invertebrate Zoology and corresponding author on the paper. "These results offer important clues to an evolutionary event that fundamentally changed the trajectory of the evolution of not just photosynthetic algae and land plants, but also animals."

In green algae and land plants, photosynthesis, or the conversion of light into food, is carried out by a specialized cell structure known as a chloroplast. The origin of chloroplast is linked to endosymbiosis, a process in which a single-celled eukaryote—an organism whose cells contain a nucleus—captures a free-living photosynthetic cyanobacterium but does not digest it, allowing the photosynthetic cell to eventually evolve into a chloroplast. The specific feeding mechanisms for this process, however, have remained largely unknown until now.

In this study, researchers used transmission electron microscopy and feeding and staining experiments to take conclusive images showing how a basic green alga from the genus Cymbomonas feeds on bacteria. The alga draws bacterial cells into a tubular duct through a mouth-like opening and then transports these food particles into a large, acidic vacuole where digestion takes place. The complexity of this feeding system in photosynthetic modern alga suggests that this bacteria-feeding behavior, and the unique feeding apparatus to support it, descend from colorless ancestors of green algae and land plants and may have played important roles in the evolution of early photosynthetic eukaryotes, the precursors to plants like trees and shrubs that cover the Earth today.

Eunsoo Kim joined the Museum in 2012 as curator of the protist collection, which includes algae, protozoa, and fungus-like protists. A native of South Korea, Kim received her Ph.D. in botany from the University of Wisconsin-Madison and conducted postdoctoral research at Dalhousie University in Halifax, Nova Scotia. She works closely with associate curator Susan Perkins and curator Rob DeSalle as part of one of the first natural history museum microbial research programs.

Shinichiro Mauyama, currently a postdoctoral researcher at the Division of Environmental Photobiology at the National Institute for Basic Biology in Okazaki, Japan, is a co-author on this paper. In addition to Kim's laboratory at the Museum, this work was conducted in John Archibald's laboratory at Dalhousie University. Funding was provided by the American Museum of Natural History and Japan Society for the Promotion of Science.



INFORMATION:

Watch Kim talk about the new finding and see green algae in action in this video: http://www.youtube.com/watch?v=lafL_mmv3EA



ELSE PRESS RELEASES FROM THIS DATE:

Death rates decline for advanced heart failure patients, but outcomes are still not ideal

2013-05-24
UCLA researchers examining outcomes for advanced heart-failure patients over the past two decades have found that, coinciding with the increased availability and use of new therapies, overall mortality has decreased and sudden cardiac death, caused by the rapid onset of severe abnormal heart rhythms, has declined. However, the team found that even today, with these significant improvements, one-third of patients don't survive more than three years after being diagnosed with advanced disease. Heart failure is increasingly common, affecting close to 6 million individuals ...

Syracuse University professor argues Earth's mantle affects long-term sea-level rise estimates

2013-05-24
From Virginia to Florida, there is a prehistoric shoreline that, in some parts, rests more than 280 feet above modern sea level. The shoreline was carved by waves more than 3 million years ago—possible evidence of a once higher sea level, triggered by ice-sheet melting. But new findings by a team of researchers, including Robert Moucha, assistant professor of Earth Sciences in Syracuse University's College of Arts and Sciences, reveal that the shoreline has been uplifted by more than 210 feet, meaning less ice melted than expected. Equally compelling is the fact that ...

H7N9 animal model looks at transmission of H7N9 influenza virus

2013-05-24
Toronto – May 23, 2013 – Embargoed until 2:00 PM – An international team of scientists has proved that the H7N9 influenza virus is efficiently transmitted when animals are in close contact -- defined in the study as touching, coughing and the exchange of bodily fluids. "This study was designed to give us clues about the transmission of H7N9 which has affected some humans in China," said David Kelvin, PhD, a senior scientist at the Toronto General Research Institute and Professor at the University of Toronto. "The animals used in the study had very mild clinical symptoms ...

University of Illinois biophysicists measure mechanism that determines fate of living cells

2013-05-24
Cells in the human body do not function in isolation. Living cells rely on communication with their environment—neighboring cells and the surrounding matrix—to activate a wide range of cellular functions, including reproduction of new cells, differentiation of stem cells into distinct cell types, cell adhesion, and migration of white blood cells to fight bodily infections. This cellular communication occurs on the molecular level and it is reciprocal: a cell receives cues from and also transmits function-activating cues to its neighbors. The mechanics of this type of ...

UC Santa Barbara scientists discover cinnamon compounds' potential ability to prevent Alzheimer's

2013-05-24
Cinnamon: Can the red-brown spice with the unmistakable fragrance and variety of uses offer an important benefit? The common baking spice might hold the key to delaying the onset of –– or warding off –– the effects of Alzheimer's disease. That is, according to Roshni George and Donald Graves, scientists at UC Santa Barbara. The results of their study, "Interaction of Cinnamaldehyde and Epicatechin with Tau: Implications of Beneficial Effects in Modulating Alzheimer's Disease Pathogenesis," appears in the online early edition of the Journal of Alzheimer's Disease, and ...

Ferrets, pigs susceptible to H7N9 avian influenza virus

2013-05-24
Chinese and U.S. scientists have used virus isolated from a person who died from H7N9 avian influenza infection to determine whether the virus could infect and be transmitted between ferrets. Ferrets are often used as a mammalian model in influenza research, and efficient transmission of influenza virus between ferrets can provide clues as to how well the same process might occur in people. The research was supported, in part, by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health. The researchers dropped H7N9 virus into ...

Reforestation study shows trade-offs between water, carbon and timber

2013-05-24
More than 13,000 ships per year, carrying more than 284 million tons of cargo, transit the Panama Canal each year, generating roughly $1.8 billion dollars in toll fees for the Panama Canal Authority. Each time a ship passes through, more than 55 million gallons of water are used from Gatun Lake, which is also a source of water for the 2 million people living in the isthmus. However, the advent of very large "super" cargo ships, now more than 20 percent of the ships at sea, has demanded change. The Panama Canal is being expanded to create channels and locks three times ...

New filtration material could make petroleum refining cheaper, more efficient

2013-05-24
A newly synthesized material might provide a dramatically improved method for separating the highest-octane components of gasoline. Measurements at the National Institute of Standards and Technology (NIST) have clarified* why. The research team, which included scientists from NIST and several other universities, has published its findings in the journal Science.* Created in the laboratory of Jeffrey Long, professor of chemistry at the University of California, Berkeley, the material is a metal-organic framework, or MOF, which can be imagined as a sponge with microscopic ...

Cradle turns smartphone into handheld biosensor

2013-05-24
CHAMPAIGN, Ill. — Researchers and physicians in the field could soon run on-the-spot tests for environmental toxins, medical diagnostics, food safety and more with their smartphones. University of Illinois at Urbana-Champaign researchers have developed a cradle and app for the iPhone that uses the phone's built-in camera and processing power as a biosensor to detect toxins, proteins, bacteria, viruses and other molecules. Having such sensitive biosensing capabilities in the field could enable on-the-spot tracking of groundwater contamination, combine the phone's GPS ...

Vaccine blackjack: IL-21 critical to fight against viral infections

2013-05-24
Scientists at Emory Vaccine Center have shown that an immune regulatory molecule called IL-21 is needed for long-lasting antibody responses in mice against viral infections. The results are published in the Journal of Virology. "Our findings highlight how IL-21 could be important in the development of antiviral vaccines," says research associate Ata Ur Rasheed Mohammed, PhD, the first author of the paper. The senior author is Rafi Ahmed, PhD, director of the Emory Vaccine Center and a Georgia Research Alliance Eminent Scholar. The findings could lead scientists designing ...

LAST 30 PRESS RELEASES:

Public take the lead in discovery of new exploding star

What are they vaping? Study reveals alarming surge in adolescent vaping of THC, CBD, and synthetic cannabinoids

ECMWF - delivering forecasts over 10 times faster and cutting energy usage by 1000

Brazilian neuroscientist reveals how viral infections transform the brain through microscopic detective work

Turning social fragmentation into action through discovering relatedness

Cheese may really be giving you nightmares, scientists find

Study reveals most common medical emergencies in schools

Breathable yet protective: Next-gen medical textiles with micro/nano networks

Frequency-engineered MXene supercapacitors enable efficient pulse charging in TENG–SC hybrid systems

Developed an AI-based classification system for facial pigmented lesions

Achieving 20% efficiency in halogen-free organic solar cells via isomeric additive-mediated sequential processing

New book Terraglossia reclaims language, Country and culture

The most effective diabetes drugs don't reach enough patients yet

Breast cancer risk in younger women may be influenced by hormone therapy

Strategies for staying smoke-free after rehab

Commentary questions the potential benefit of levothyroxine treatment of mild hypothyroidism during pregnancy

Study projects over 14 million preventable deaths by 2030 if USAID defunding continues

New study reveals 33% gap in transplant access for UK’s poorest children

Dysregulated epigenetic memory in early embryos offers new clues to the inheritance of polycystic ovary syndrome (PCOS)

IVF and IUI pregnancy rates remain stable across Europe, despite an increasing uptake of single embryo transfer

It takes a village: Chimpanzee babies do better when their moms have social connections

From lab to market: how renewable polymers could transform medicine

Striking increase in obesity observed among youth between 2011 and 2023

No evidence that medications trigger microscopic colitis in older adults

NYUAD researchers find link between brain growth and mental health disorders

Aging-related inflammation is not universal across human populations, new study finds

University of Oregon to create national children’s mental health center with $11 million federal grant

Rare achievement: UTA undergrad publishes research

Fact or fiction? The ADHD info dilemma

Genetic ancestry linked to risk of severe dengue

[Press-News.org] Scientists offer first definitive proof of bacteria-feeding behavior in green algae
Study gives look at early evolutionary event that paved way for land plants, animals