Clipmarks | Mohir's 'genetics' clips

'Biological clock' genes control plant growth

Tue, 16 Sep 2008 16:54:46 GMT

clipped by: Mohir
clipper's remarks: When such mechanisms are more fully analyzed, it may be possible to influence them with genetic modification,

Clip Source: www.physorg.com

More than 125 years ago Charles Darwin first reported that most plants grow in a spurt during the night, not the day – and this week, scientists are reporting the discovery of the genes that control this phenomenon.

These rhythmic growth spurts, and the ability of plants to move in response to light, are actually controlled by genes involved in circadian rhythms – the "biological clock" genes that are influenced by light and dark, vary their activity based on time of day, and are increasingly found in both plants and animals to control a wide variety of functions, ranging from growth to nervous system function and even fertility.

Ultimately, more understanding of these growth genetics could allow scientists to create plants that grow faster, produce more food or have other useful characteristics, the researchers said.

Tags: genetics, growth, biological clock

How genes pick our mates for us

Sun, 14 Sep 2008 21:25:48 GMT

clipped by: Mohir
clipper's remarks: Instead of smelly T-shirts, Chaix and colleague Peter Donnelly of the University of Oxford studied previously gathered genetic data on 30 Caucasian couples from Utah and 30 Yoruba couples from Nigeria. The researchers analysed about 9000 genetic differences within the MHC genes, as well as more than 3 million differences dotted across the rest of their genomes.

This suggests that the American couples are selecting mates, in large part, based on MHC genes.

Not so for Yoruba couples, who seemed to pick mates with MHC genes no more different than would be expected for any two people picked at random from the population.
One explanation for the different findings could be diversity. Overall, Yoruba people had more differences in their MHC genes than Americans, so there could be less evolutionary pressure to find a mate with new genes.

Clip Source: www.newscientist.com

When picking a husband or wife, American couples seek out new immune genes, while Africans stick to the ones they've got.

New research shows that American couples of European ancestry go for mates with versions of immune genes that recognise pathogens dissimilar from those their own genes recognise. These genes are part of the major histocompatibility complex, and the more MHC genes a person has, the greater variety of pathogens his or her immune system recognises.

Previous work in fish, lizards and birds has suggested that animals seek out mates with different MHC genes than their own. Yet studies in humans have painted a far blurrier picture of MHC-driven mating preferences.

“It seems that body odours can reveal someone’s immune genetics, and so through the smell we could be able to distinguish the MHC genes from different potential mates,” says Raphaëlle Chaix, a human population geneticist at the National Centre for Scientific Research in Paris, France.

Tags: genetics, mates, immune system

The Genetic Early Adopters

Tue, 09 Sep 2008 14:03:33 GMT

clipped by: Mohir
clipper's remarks: Knome is at the forefront of the push toward so-called personalized medicine. Scientists and physicians hope that when sequencing costs come down enough, genetic analysis will become a ubiquitous part of health care, helping doctors choose the best treatments for a specific patient, or helping individuals take steps to prevent diseases for which they are at risk.

Clip Source: www.technologyreview.com

The first people to purchase their complete genome sequences browse their books of life.

Last month, Jorge Conde handed out the first of his company's precious products: an engraved silver box housing a USB drive. On the drive, protected by encryption software, was the sequence of the recipient's entire genome, a proprietary analysis of his genetic risks for disease, and software for browsing the data.

The event signals a shift in the world of human genome sequencing. Until now, the handful of people who have had their genomes sequenced, including genomics pioneers Craig Venter and James Watson, have been part of government or industry efforts to study the human genome or showcase new sequence technologies. But thanks to Knome, a startup based in Cambridge, MA, genome sequencing is no longer just a research tool. Anyone with $350,000 to spare and an adventurous spirit can now have his or her own genome sequenced.

Tags: genetics

Human Obesity Genes Revealed Based On Fly Experiments

Mon, 11 Aug 2008 20:54:22 GMT

clipped by: Mohir
clipper's remarks: As De Luca reports, "We found one variant to be associated with weight and lean mass in both ethnic groups. This variant was also associated with height, total fat mass and HDL-cholesterol, but only in European American women. A different variant was associated with triglyceride levels and HDL-cholesterol in African American women."

The use of flies in a study of human obesity may seem strange, but according to De Luca "Insects store fat like mammals do, as lipid droplets accumulated in the fat body, the functional equivalent of both mammalian liver and white adipose tissue". She adds that, "Drosophila share many components of fat biosynthesis, degradation and regulation with humans, including many of those implicated in diabetes and obesity".

Clip Source: www.sciencedaily.com

A study of 228 women has revealed genetic variants responsible for body shape. Based on work in the fruit fly Drosophila melanogaster, research published in the open access journal BMC Genetics identifies natural variation in the human LAMA5 gene as a key determinant of weight.

As the prevalence of obesity and related health problems continues to increase worldwide, there is considerable effort being devoted to identify genetic mechanisms that control fat storage. Maria De Luca led a team from the University of Alabama at Birmingham, USA, who identified candidate genes using different strains of Drosophila.

On the basis of the results of these fly experiments, the research team then tested three common variations in the human LAMA5 gene and discovered two gene variants that were associated with body shape, one in women of European American descent and the other affecting women of American African descent

Tags: obesity, genetics

Genetics Show How Prehistoric Cultures Migrated & Shared Knowledge

Thu, 07 Aug 2008 15:14:24 GMT

clipped by: Mohir
clipper's remarks: The researchers tracked genetic variation on the Y chromosome, the sex chromosome passed from father to son that encodes maleness, using a technique now widely used that was developed in the early 1990s by Underhill and colleagues in the lab of Luigi Cavalli-Sforza, professor emeritus of genetics. The method has given scientists a powerful window into ancient human migrations and prehistoric cultural shifts. The technique has also been adopted by some commercial genealogy services that offer Y-chromosome testing to the public.

Clip Source: www.dailygalaxy.com

Using a genetic technique pioneered at Stanford, a research team found that animal-herding methods arrived in southern Africa 2,000 years ago on a wave of human migration, rather than by movement of ideas between neighbors as previously believed.

Prior research suggested that prehistoric people in eastern and southern Africa had little contact, with only two known migrations between the regions about 30,000 and 1,500 years ago. After Bantu-language speakers migrated from eastern to southern Africa 1,500 years ago, agriculture took off in southern Africa. But the timing of the Bantu migration didn't quite match the 2,000-year-old anthropological evidence for the first sheep and cattle herds in southern Africa, so anthropologists were unsure whether the region's agricultural knowledge came from a wave of ideas that spread in front of the migrating Bantu, or whether a separate migration brought the first herders.

Tags: genetics

What Do Your Genes Say About You? The Future of Personal Genomics

Wed, 23 Jul 2008 21:21:02 GMT

clipped by: Mohir
clipper's remarks: The company 23andMe announced its DNA testing service last month in San Diego. You might think such a comprehensive analysis would costs thousands, but the process is actually relatively affordable. For less than $1,000 customers are able to learn virtually everything science currently knows about their biological code. For those wary of needles, you’ll be comforted to know that the DNA is retrieved conveniently and painlessly from a home mail-in saliva test kit.

Clip Source: www.dailygalaxy.com

Want to know what your genes say about you? According to geneticists, your genes could be saying quite a lot! Your genetics may dictate, for example, what foods you like, what diseases you are prone to develop, how smart you are, and likely factor into nearly every aspect of your being. It’s no wonder that some people would like to take a peek at their personal genetic blueprint.

Three companies are now offering such services. Not only will they test your DNA at nearly one million separate locations where the human genome is known to vary from person to person, but they also help clients interpret what their individual map says about their past, present and future. However, genetics is still an imperfect science. Your genes could indicate you have a very high risk of developing arthritis down the road, for example, but in actuality you may never suffer from stiff joints.

scientists have been mapping out genetic differences for some time now, and have made huge strides in interpreting DNA

Tags: dna, genetics

Wikipedia opens online library on human genes

Tue, 08 Jul 2008 15:12:14 GMT

clipped by: Mohir

Clip Source: www.physorg.com

A group of US researchers laid out the foundations Monday for a new online library on human genetics stored within the existing framework of open-access encyclopedia Wikipedia.

"There are about 25,000 genes in the humane genome. We have 9,000 articles," said Andrew Su, one of those behind the "Gene Wiki" project from the Genomics Institute at the Novartis Research Foundation in San Diego, California.

"Our goal is to provide a uniform starting point for all genes," he said, noting that afterwards it was up to other scientists to add information and keep it up to date, as happens now with Wikipedia entries.

"The entire community will generate content and also oversee that content."

Tags: wikipedia, genes, genetics, library

The ADHD Advantage: Did the “Hyper” Gene Benefit Our Nomadic Ancestors?

Wed, 18 Jun 2008 19:22:24 GMT

clipped by: Mohir
clipper's remarks: "So, in other words, all of us with ADHD need to head back to the desert with a pack of camels loaded up with tents to really make the most of our “disorder” (how dare they call it that when it turns out it’s an evolutionary advantage unless you’re a semi-comatose couch potatoes). Of course half of us will absent-mindedly forget to bring essentials—like water—but we’ll have a lot of fun. Who’s with me?"

Clip Source: www.dailygalaxy.com

ADHA has gotten a bad rap in the 21st century, but all of us fidgety hyper-hypos may have evolved this way for good reason, say scientists. An ADHD-associated version of the human gene DRD4 was found to be linked to superior health among nomadic tribesmen. But oddly enough, it seems to be linked with malnourishment among their more settled cousins. Here is my completely unscientific explanation for why that might be the case: People who can’t sit still would be appreciated in a society that is always on the move, whereas in a sedentary population—like most of us live in today—we’re all but an unwanted annoyance. But whatever the real reason, scientists say these findings offer clues to why some of us evolved the way we did, and what that means for the future.

They found that those with the 7R allele in the nomadic population were better nourished than their non-nomadic brethren who carried 7R allele.

Tags: adhd, nomads, evolution, genetics

Clues To Ancestral Origin Of Placenta Emerge In Genetics Study

Thu, 17 Apr 2008 17:11:39 GMT

clipped by: Mohir
clipper's remarks: They found that the placenta develops in two distinct stages. In the first stage, which runs from the beginning of pregnancy through mid-gestation, the placental cells primarily activate genes that mammals have in common with birds and reptiles. This suggests that the placenta initially evolved through repurposing genes the early mammals inherited from their immediate ancestors when they arose more than 120 million years ago.

Clip Source: www.sciencedaily.com

Researchers at the Stanford University School of Medicine have uncovered the first clues about the ancient origins of a mother's intricate lifeline to her unborn baby, the placenta, which delivers oxygen and nutrients critical to the baby's health.

The evidence suggests the placenta of humans and other mammals evolved from the much simpler tissue that attached to the inside of eggshells and enabled the embryos of our distant ancestors, the birds and reptiles, to get oxygen.

"The placenta is this amazing, complex structure and it's unique to mammals, but we've had no idea what its evolutionary origins are,"

Tags: genetics, placenta, birth giving

Major Advance In Biofuel Technology: Trash Today, Ethanol Tomorrow

Tue, 11 Mar 2008 11:22:49 GMT

clipped by: Mohir
clipper's remarks: Major Advance In Biofuel Technology: Trash Today, Ethanol Tomorrow

Clip Source: www.sciencedaily.com

ScienceDaily (Mar. 11, 2008) — University of Maryland research that started with bacteria from the Chesapeake Bay has led to a process that may be able to convert large volumes of all kinds of plant products, from leftover brewer's mash to paper trash, into ethanol and other biofuel alternatives to gasoline.

That process, developed by University of Maryland professors Steve Hutcheson and Ron Weiner, professors of cell biology and molecular genetics, is the foundation of their incubator company Zymetis, which was on view March 10 in College Park for Maryland Governor Martin O'Malley and state and university officials.

The Zymetis process can make ethanol and other biofuels from many different types of plants and plant waste called cellulosic sources. Cellulosic biofuels can be made from non- grain plant sources such as waste paper, brewing byproducts, leftover agriculture products, including straw, corncobs and husks, and energy crops such as switchgrass.

Tags: ethanol, ecology, fuel

Identical Twins Not As Identical As Believed

Wed, 20 Feb 2008 17:44:22 GMT

clipped by: Mohir

Clip Source: www.sciencedaily.com

ScienceDaily (Feb. 20, 2008) — Contrary to our previous beliefs, identical twins are not genetically identical. This surprising finding may be of great significance for research on hereditary diseases and for the development of new diagnostic methods. How can it be that one identical twin might develop Parkinson's disease, for instance, but not the other? Until now, the reasons have been sought in environmental factors. The current study complicates the picture.

The researchers studied 19 pairs of monozygotic, or identical, twins and found differences in copy number variation in DNA. Copy number variation (CNV) occurs when a set of coding letters in DNA are missing, or when extra copies of segments of DNA are produced.

Tags: dna, twins, genetics

Genetically Engineered 'Mighty Mouse' Can Run 6 Kilometers Without Stopping

Tue, 06 Nov 2007 02:52:14 GMT

clipped by: Mohir

Clip Source: www.sciencedaily.com

Genetically Engineered 'Mighty Mouse' Can Run 6 Kilometers Without Stopping

Case Western Reserve University researchers have bred a line of "mighty mice" (PEPCK-Cmus mice) that have the capability of running five to six kilometers at a speed of 20 meters per minute on a treadmill for up to six hours before stopping.

"They are metabolically similar to Lance Armstrong biking up the Pyrenees; they utilize mainly fatty acids for energy and produce very little lactic acid," said Richard W. Hanson, the Leonard and Jean Skeggs Professor of Biochemistry at Case Western Reserve and the senior author of a journal article on this research.

These genetically engineered mice also eat 60 percent more than controls, but remain fitter, trimmer and live and breed longer than wild mice in a control group. Some female PEPCK-Cmus mice have had offspring at 2.5 years of age, an amazing feat considering most mice do not reproduce after they are one year old.

Tags: genetics, mouse, technology

A Thousand Chinese Einsteins Every Year

Wed, 03 Oct 2007 20:13:35 GMT

clipped by: Mohir
clipper's remarks: wow !!!
can be quite frightening

Clip Source: www.acceleratingfuture.com

A Thousand Chinese Einsteins Every Year Wednesday, Oct 3 2007

Imagine that in ten years China forces all its college students to get genetic tests. Students with intelligence genes in the top 1% of the top 1% of humankind are then forced to donate sperm or eggs. China then uses the sperm and eggs to create a billion embryos each year. The genetic intellectual potential of all these embryos is checked. Those in the top 10,000 are implanted into women. Each of these embryos has the intellectual potential to be in the top one-billionth of humankind.

Now because of environmental factors many of these embryos won’t turn into intellectual titans. But let’s say that one in ten does. This means that each year 1,000 people with the scientific ability of Einstein will be born. By 2035 they will become adults and start doing scientific research. I imagine these Einsteins will be rather helpful to China’s economy and military.”

Tags: einstein, genetics

Personal Genomes: Mainstream In Five Years

Fri, 21 Sep 2007 14:37:49 GMT

clipped by: Mohir

Clip Source: www.sciencedaily.com

Personal Genomes: Mainstream In Five Years, But Who Should Have Access?

Science Daily — Imagine this: you visit your clinician, undergo genetic testing, and then you are handed a miniature hard drive containing your personal genome sequence, which is subsequently uploaded onto publicly accessible databases. This may sound like science fiction, but it is scientific fact, and it is already happening.

Scientists predict that within five years DNA sequencing technologies will be affordable enough that personal genomics will be integrated into routine clinical care. Companies are responding by offering their services for ancestry tracing, forensics, nutritional advice and reproductive assistance. It won't be long before companies are able to offer Facebook-like social networking services centred around our genomes.

Tags: dna, genetics, genes, healthcare, biology

Three Smart Things You Should Know About Genomics

Mon, 10 Sep 2007 14:14:12 GMT

clipped by: Mohir

Clip Source: www.wired.com

Three Smart Things You Should Know About Genomics

1. The real benefit of studying genomes is that it has taught us how little we know. We used to think noncoding "junk" DNA didn't do anything. Now it turns out it may contain underlying instructions for how DNA works.

2. Genomics' reductionist approach has become more holistic. Now we also look at all the proteins a cell makes (proteomics), RNA transcription (transcriptomics), molecules that control which DNA gets turned on (epigenomics), and cell energy consumption (metabolomics).

3. Important genes usually exist in multiple copies, in case one iteration gets damaged. This results in lots of leftover, deactivated genes from up the evolutionary tree — solid molecular proof that Darwin was right — birds have genes for teeth; humans share genes with gorillas.

Tags: genomics, dna, rna, genetics, evolution