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

Solving a biological mystery

Researchers find that gene related to germ cell formation is far older than first thought

2012-11-01
(Press-News.org) Harvard scientists have solved the long-standing mystery of how some insects form the germ cells – the cellular precursors to the eggs and sperm necessary for sexual reproduction – and the answer is shedding new light on the evolutionary origins of a gene that had long been thought to be critical to the process.

As described in a November 1 paper published in Current Biology, a team of researchers led by Associate Professor of Organismic and Evolutionary Biology Cassandra Extavour discovered that a cricket, a so-called "lower" insect, possess a variation of a gene, called oskar, that has been shown to be critical to the production of germ cells in "higher" insects, particularly fruit flies. That discovery, Extavour said, suggests that the oskar gene emerged far earlier in insect evolution than researchers previously believed.

"The prevailing hypothesis was that, since only higher insects appeared to possess the oskar gene, that it must have emerged after the two branches of insect evolution diverged," Extavour said. "We found that that can't be right. Oskar is present in both groups of insects, so it must have emerged in their last common ancestor."

Aside from rewriting science's understanding of how germ lines evolved in insects, the finding is also shining fresh light on the importance of looking beyond the traditional models for biological research. Had her team not reached beyond the oft-used fruit fly model, Extavour said, their discovery of the evolutionary history of oskar likely would not have happened.

"There are some questions, especially deep evolutionary questions, you can never get at by examining only one animal," said Extavour, who also serves as the director of the Evo-Devo-Eco Network (EDEN), an initiative funded by the National Science Foundation aimed at providing support to researchers who work outside the traditional model organisms. "And you certainly can't get at them by examining animals that are very far removed from their last common ancestor, as the evidence shows fruit flies are."

"The whole concept of the model organism is based on the principle that what works in one organism works the same way, or a very similar way, in another organism," Extavour said. "The more we know about biology, the more we understand that that's not always the case."

While their findings provide an answer to a riddle that had long stumped biologists, Extavour and her colleagues began their research by asking a simple question: Since germ cells are critical to the reproduction of so many plants and animals, could there be a single genetic pathway – one that evolution never tinkered with – to create them?

Scientists have long understood that higher insects like fruit flies use a process called maternal inheritance, in which the mother loads material – including the oskar gene – into eggs before they are laid. That material, called germ plasm, later causes the cells containing it to become germ cells.

Among most "lower" insects, however, the process of forming germ cells is completely different, Extavour said, and understanding it provided hints that the oskar gene's original role likely had nothing to do with germ cells.

While Extavour's team found that "lower" insects like crickets do have a variation of the oskar gene, they were surprised to find that it appears to have little to do with forming germ cells. Unlike fruit flies, which cannot form germ cells without oskar, removing the gene from crickets has no effect on germ cell formation.

"What that means is that even though oskar emerged much earlier in evolution than we suspected, this role that we've been talking about for more than three decades – oskar has only been talked about in the context of being a germ line gene – this may not be the ancestral role it played," Extavour said. "Somewhere along the line, it changed jobs."

What was oskar's original job, then, if it wasn't to form germ cells?

When they examined crickets, researchers found the gene not in germ cells, but in neural stem cells called neuroblasts, suggesting that its original role was in the nervous system. Supporting this hypothesis was their observation that removing the gene from crickets caused defects in neuron production and nervous system wiring.

"Our argument is basically that in the last common ancestor of insects, the ancestral role for oskar was most likely in wiring the nervous system," she said. "Somewhere along the line, it got co-opted into this germ line pathway, and eventually rose to prominence in the hierarchy of genes that control germ cell formation."

### END


ELSE PRESS RELEASES FROM THIS DATE:

Living donors fare well following liver transplantation

2012-11-01
Researchers in Japan report that health-related quality of life (HRQOL) for donors following living donor liver transplantation (LDLT) was better than the general Japanese population (the norm). This study—one of the largest to date—found that donors who developed two or more medical problems (co-morbidities) after donation had significantly decreased long-term HRQOL. Full findings are published in the November issue of Liver Transplantation, a journal of the American Association for the Study of Liver Diseases (AASLD). The shortage of viable donor organs continues to ...

A protein’s role in helping cells repair DNA damage

2012-11-01
BUFFALO, N.Y. -- In a new study, University at Buffalo scientists describe the role that a protein called TFIIB plays in helping cells repair DNA damage, a critical function for preventing the growth of tumors. The research appeared online on Oct. 30 in the Proceedings of the National Academy of Sciences (PNAS) Early Edition. TFIIB, short for "transcription factor II B," is a protein that binds to DNA in cells to initiate the process of transcription, which is critical for building new proteins. When DNA damage occurs, TFIIB is altered in a way that halts general transcription, ...

New target discovered for food allergy treatment

2012-11-01
Researchers at National Jewish Health have discovered a novel target for the treatment of food allergies. Erwin Gelfand, MD, and his colleagues report in the October 2012 issue of the Journal of Allergy and Clinical Immunology that levels of the enzyme Pim 1 kinase rise in the small intestines of peanut-allergic mice. Inhibiting activity of Pim 1 markedly reduced the allergic response to peanuts. "Pim 1, and its associated transcription factor, Runx3, play a crucial role in allergic reactions to peanuts," said Dr. Gelfand, senior author and chair of pediatrics at National ...

Air pollution, gone with the wind

Air pollution, gone with the wind
2012-11-01
Montreal, November 1, 2012 – As urban populations expand, downtown buildings are going nowhere but up. The huge energy needs of these skyscrapers mean that these towers are not only office buildings, they're polluters with smokestacks billowing out toxins from the rooftop. Our cities are dirtier than we think. New research from Concordia University just might clean them up. By examining the trajectory and amount of air pollution from a building to its neighbours downwind, Concordia researchers Ted Stathopoulos and Bodhisatta Hajra have come up with environmentally friendly ...

Anthropocene continues to spark scientific debate

2012-11-01
Boulder, CO, USA – How have humans influenced Earth? Can geoscientists measure when human impacts began overtaking those of Earth's other inhabitants and that of the natural Earth system? Responding to increasing scientific recognition that humans have become the foremost agent of change at Earth's surface, organizers of this GSA technical session have brought together speakers and poster presentations from a variety of sources in order to answer these questions and define the "Geomorphology of the Anthropocene." "Anthropocene" is a fairly new term (first used ca. 2002 ...

Scientists launch international study of open-fire cooking and air quality

Scientists launch international study of open-fire cooking and air quality
2012-11-01
Contact: David Hosansky hosansky@ucar.edu 303-497-8611 National Center for Atmospheric Research/University Corporation for Atmospheric Research Zhenya Gallon zhenya@ucar.edu 303-497-8607 National Center for Atmospheric Research/University Corporation for Atmospheric Research Christine Wiedinmyer christin@ucar.edu 303-497-1414 National Center for Atmospheric Research Mary Hayden mhayden@ucar.edu 303-497-8116 National Center for Atmospheric Research Scientists launch international study of open-fire cooking and air quality BOULDER -- Expanding ...

Genetic test results for Lynch syndrome improved with new computer program

2012-11-01
SALT LAKE CITY—Many patients who have genetic testing for Lynch syndrome, a hereditary predisposition to colon cancer, receive the inconclusive result "variants of uncertain clinical significance." This can be a problem, as people with Lynch syndrome have a much higher probability to develop colon cancer, and often develop colon cancer at an earlier age than is common among the general population; consequently, they need to begin screening at a much younger age. Now, between two-thirds and three-fourths of these genetic variants can be classified into categories that ...

Brain may 'see' more than the eyes, study indicates

2012-11-01
Vision may be less important to "seeing" than is the brain's ability to process points of light into complex images, according to a new study of the fruit fly visual system currently published in the online journal Nature Communications. University of Virginia researchers have found that the very simple eyes of fruit fly larvae, with only 24 total photoreceptors (the human eye contains more than 125 million), provide just enough light or visual input to allow the animal's relatively large brain to assemble that input into images. "It blows open how we think about vision," ...

IU researchers report first effective treatment of tumors arising from common genetic disease NF1

IU researchers report first effective treatment of tumors arising from common genetic disease NF1
2012-11-01
Physician-researchers at Indiana University School of Medicine have reported the first effective therapy for a class of previously untreatable and potentially life-threatening tumors often found in children. Announcing their findings in the online first edition of Lancet Oncology, the researchers said the drug imatinib mesylate, marketed as Gleevec as a treatment for chronic myeloid leukemia, provided relief to a significant number of patients with plexiform neurofibromas, tumors caused by neurofibromatosis type 1, or NF1. "Although this was a small study, the results ...

Super-rare, super-luminous supernovae are likely explosion of universe's earliest stars

Super-rare, super-luminous supernovae are likely explosion of universes earliest stars
2012-11-01
The most-distant, super-luminous supernovae found to date have been observed by an international team, including Raymond Carlberg of the University of Toronto's Department of Astronomy & Astrophysics. The stellar explosions would have occurred at a time when the universe was much younger and probably soon after the Big Bang. "The objects are both unusually bright and unusually slow to fade. These are properties that are consistent with what is known as pair-instability supernova, a rare mechanism for explosion which is expected to happen for high-mass stars with almost ...

LAST 30 PRESS RELEASES:

Engineers uncover why tiny particles form clusters in turbulent air

GLP-1RA drugs dramatically reduce death and cardiovascular risk in psoriasis patients

Psoriasis linked to increased risk of vision-threatening eye disease, study finds

Reprogramming obesity: New drug from Italian biotech aims to treat the underlying causes of obesity

Type 2 diabetes may accelerate development of multiple chronic diseases, particularly in the early stages, UK Biobank study suggests

Resistance training may improve nerve health, slow aging process, study shows

Common and inexpensive medicine halves the risk of recurrence in patients with colorectal cancer

SwRI-built instruments to monitor, provide advanced warning of space weather events

Breakthrough advances sodium-based battery design

New targeted radiation therapy shows near-complete response in rare sarcoma patients

Does physical frailty contribute to dementia?

Soccer headers and brain health: Study finds changes within folds of the brain

Decoding plants’ language of light

UNC Greensboro study finds ticks carrying Lyme disease moving into western NC

New implant restores blood pressure balance after spinal cord injury

New York City's medical specialist advantage may be an illusion, new NYU Tandon research shows

Could a local anesthetic that doesn’t impair motor function be within reach?

1 in 8 Italian cetacean strandings show evidence of fishery interactions, with bottlenose and striped dolphins most commonly affected, according to analysis across four decades of data and more than 5

In the wild, chimpanzees likely ingest the equivalent of several alcoholic drinks every day

Warming of 2°C intensifies Arctic carbon sink but weakens Alpine sink, study finds

Bronze and Iron Age cultures in the Middle East were committed to wine production

Indian adolescents are mostly starting their periods at an earlier age than 25 years ago

Temporary medical centers in Gaza known as "Medical Points" (MPs) treat an average of 117 people daily with only about 7 staff per MP

Rates of alcohol-induced deaths among the general population nearly doubled from 1999 to 2024

PLOS One study: In adolescent lab animals exposed to cocaine, High-Intensity Interval Training boosts aversion to the drug

Scientists identify four ways our bodies respond to COVID-19 vaccines

Stronger together: A new fusion protein boosts cancer immunotherapy

Hidden brain waves as triggers for post-seizure wandering

Music training can help the brain focus

Researcher develop the first hydride ion prototype battery

[Press-News.org] Solving a biological mystery
Researchers find that gene related to germ cell formation is far older than first thought