Tag Archives | DNA

Researchers may have solved origin-of-life conundrum

Shan Sheehan (CC BY 2.0)

Shan Sheehan (CC BY-ND 2.0)

Which came first, the chicken or the egg? Researchers may have come up with the answer.

Robert Service via AAAS:

The origin of life on Earth is a set of paradoxes. In order for life to have gotten started, there must have been a genetic molecule—something like DNA or RNA—capable of passing along blueprints for making proteins, the workhorse molecules of life. But modern cells can’t copy DNA and RNA without the help of proteins themselves. To make matters more vexing, none of these molecules can do their jobs without fatty lipids, which provide the membranes that cells need to hold their contents inside. And in yet another chicken-and-egg complication, protein-based enzymes (encoded by genetic molecules) are needed to synthesize lipids.

Now, researchers say they may have solved these paradoxes. Chemists report today that a pair of simple compounds, which would have been abundant on early Earth, can give rise to a network of simple reactions that produce the three major classes of biomolecules—nucleic acids, amino acids, and lipids—needed for the earliest form of life to get its start.

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Sea Slug Has Taken Genes from Algae It Eats, Allowing It to Photosynthesize like a Plant

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

Diana Kenney via Marine Biological Laboratory:

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.

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NASA Ames reproduces the building blocks of life in laboratory

Left to right: Ames scientists Michel Nuevo, Christopher Materese and Scott Sandford reproduce uracil, cytosine, and thymine, three key components of our hereditary material, in the laboratory. Credit: NASA/ Dominic Hart

Left to right: Ames scientists Michel Nuevo, Christopher Materese and Scott Sandford reproduce uracil, cytosine, and thymine, three key components of our hereditary material, in the laboratory.

Credit: NASA/ Dominic Hart

Via Science Daily:

NASA scientists studying the origin of life have reproduced uracil, cytosine, and thymine, three key components of our hereditary material, in the laboratory. They discovered that an ice sample containing pyrimidine exposed to ultraviolet radiation under space-like conditions produces these essential ingredients of life.

Pyrimidine is a ring-shaped molecule made up of carbon and nitrogen and is the central structure for uracil, cytosine, and thymine, which are all three part of a genetic code found in ribonucleic (RNA) and deoxyribonucleic acids (DNA). RNA and DNA are central to protein synthesis, but also have many other roles.

“We have demonstrated for the first time that we can make uracil, cytosine, and thymine, all three components of RNA and DNA, non-biologically in a laboratory under conditions found in space,” said Michel Nuevo, research scientist at NASA’s Ames Research Center, Moffett Field, California.

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Half of DNA found on NYC Subways Does Not Match Any Known Organism

So if “[a]lmost half of the DNA found on the [New York City Subway] system’s surfaces did not match any known organism and just 0.2 percent matched the human genome,” then where does it come from? Anyone? From the New York Times:

Have you ever been on the subway and seen something that you did not quite recognize, something mysteriously unidentifiable?

Well, there is a good chance scientists do not know what it is either.

NY subway life

Researchers at Weill Cornell Medical College released a study on Thursday that mapped DNA found in New York’s subway system — a crowded, largely subterranean behemoth that carries 5.5 million riders on an average weekday, and is filled with hundreds of species of bacteria (mostly harmless), the occasional spot of bubonic plague, and a universe of enigmas. Almost half of the DNA found on the system’s surfaces did not match any known organism and just 0.2 percent matched the human genome.

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Changing Our DNA through Mind Control?

Marguerite Agniel in a Buddha position with her legs crossed Wellcome V0048585.jpg

Marguerite Agniel, photo from Wellcome Library (CC)

A study finds meditating cancer patients are able to affect the makeup of their DNA, reports Scientific American:

“I think, therefore I am” is perhaps the most familiar one-liner in western philosophy. Even if the stoners, philosophers and quantum mechanically-inclined skeptics who believe we’re living an illusion are right, few existential quips hit with such profound, approachable simplicity.  The only catch is that in Descartes’ opinion, “we” – our thoughts, our personalities, our “minds” – are mostly divorced from our bodies.

The polymathic Frenchman and other dualist philosophers proposed that while the mind exerts control over our physical interaction with the world, there is a clear delineation between body and mind; that our material forms are simply temporary housing for our immaterial souls. But centuries of science argue against a corporeal crash pad. The body and mind appear inextricably linked. And findings from a new study published in Cancer by a Canadian group suggest that our mental state has measurable physical influence on us – more specifically on our DNA.

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Nanotechnology to outer space: ten top tech innovations of 2014

This article was originally published on The Conversation.
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By David Green, Monash University

Don’t be mesmerised by cool apps and flashy new gizmos – the top technology inventions of the year are ones that will have a lasting effect.

Most are advances in fields that are already changing us. Some will have immediate impact; others are portents of transformations that may take decades to complete. In this vein, and in no particular order, here are what I consider to be ten of the best technological innovations from 2014.

1. DNA nanobots injected into cockroaches

Nanotechnology is a growing research field that manipulates materials on a molecular scale. One prospect is to transform medicine by injecting nanobots into the body where they perform functions such as treating disease.

Researchers injected DNA into cockroaches. Tom Spinker/Flickr, CC BY-NC-ND

In February, an Israeli team described devices they made from DNA and injected into cockroaches.… Read the rest

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Viking families traveled together, research shows

Frank Douwes CC BY 2.0

Frank Douwes (CC BY 2.0)

via Phys.org:

(Phys.org)—A new study shows that when Vikings moved to new territories, men and women traveled together. Erika Hagelberg of the University of Oslo and her colleagues compared ancient Norse and Icelandic mitochondrial DNA with mitochondrial DNA of modern Northwestern Europeans. They found similarities between the ancient and modern DNA suggesting women played a significant role in Viking migrations. The research appears in The Royal Society Philosophical Transactions B.

Vikings traveled long distances, establishing colonies in Iceland and many parts of Northwestern Europe. They even traveled as far as North America. It’s a commonly held belief that Viking expeditions consisted entirely of men, and that a shortage of women at home compelled Viking men to seek out women in foreign lands. Earlier genetic studies have suggested that while Viking men ventured forth to pillage and plunder, women and children stayed home.

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Combining The DNA Of Three People Raises Ethical Questions

Stuart Caie (CC BY 2.0)

Stuart Caie (CC BY 2.0)

via NPR:

In a darkened lab in the North of England, a research associate is intensely focused on the microscope in front of her. She carefully maneuvers a long glass tube that she uses to manipulate early human embryos.

“It’s like microsurgery,” says Laura Irving of Newcastle University.

Irving is part of a team of scientists trying to replace defective DNA with healthy DNA. They hope this procedure could one day help women who are carrying genetic disorders have healthy children.

“We are talking about conditions for which there is currently no cure,” says Dr. Doug Turnbull, a professor of neurology at Newcastle University who is leading the research. These mitochondrial diseases are caused by hereditary defects in human cells.

“Mitochondria are like little power stations present in all our cells,” Turnbull says. These power stations provide the energy that cells need. If the mitochondrial DNA is defective, the cells don’t work right.

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Epigenetic Tie to Neuropsychiatric Disorders Found

2D structure of neurotransmitter dopamine. Created with BKChem and Extensible SVG Optimiser

2D structure of neurotransmitter dopamine. Created with BKChem and Extensible SVG Optimiser

Could this discovery lead to the end of “treating” mental illness through the endless prescribing of psychiatric drugs?

Via ScienceDaily:

Dysfunction in dopamine signaling profoundly changes the activity level of about 2,000 genes in the brain’s prefrontal cortex and may be an underlying cause of certain complex neuropsychiatric disorders, such as schizophrenia, according to UC Irvine scientists.

This epigenetic alteration of gene activity in brain cells that receive this neurotransmitter showed for the first time that dopamine deficiencies can affect a variety of behavioral and physiological functions regulated in the prefrontal cortex.

The study, led by Emiliana Borrelli, a UCI professor of microbiology & molecular genetics, appears online in the journal Molecular Psychiatry.

“Our work presents new leads to understanding neuropsychiatric disorders,” Borrelli said. “Genes previously linked to schizophrenia seem to be dependent on the controlled release of dopamine at specific locations in the brain.

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Family Violence Leaves Genetic Imprint on Children

Pic: US ARMY (PD)

Pic: US ARMY (PD)

Via ScienceDaily:

A new Tulane University School of Medicine study finds that the more fractured families are by domestic violence or trauma, the more likely that children will bear the scars down to their DNA.

Researchers discovered that children in homes affected by domestic violence, suicide or the incarceration of a family member have significantly shorter telomeres, which is a cellular marker of aging, than those in stable households. The findings are published online in the latest issue of the journal Pediatrics.

Telomeres are the caps at the end of chromosomes that keep them from shrinking when cells replicate. Shorter telomeres are linked to higher risks for heart disease, obesity, cognitive decline, diabetes, mental illness and poor health outcomes in adulthood. Researchers took genetic samples from 80 children ages 5 to 15 in New Orleans and interviewed parents about their home environments and exposures to adverse life events.

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