MetaFilter posts tagged with DNA

Learn.Genetics

netbros — Sat, 31 Oct 2009 16:35:03 -0800

grumblebee's post about cell size and scale the other day was quite fascinating. Pulling back to the home for that site, the Genetic Science Learning Center at the University of Utah delivers educational materials on genetics, bio-science and health topics ranging from stem cells to gene therapy, and from epigenetics to heredity. Explore the neurobiology of normal and addicted brains and the genetic contribution to this chronic disease.

Blood sucking leeches

caddis — Tue, 20 Oct 2009 07:59:18 -0800

Leeches, horror film staples, medicinal wonders, and now crime fighters. Police cracked the case of a home invasion and safe robbery when they found one of the suspects' blood inside a leech on the floor and matched his dna.

Gene Genie

storybored — Mon, 19 Oct 2009 10:53:58 -0800

I.B.M. Joins Pursuit of $1,000 Personal Genome The target is remarkable given that the original Human Genome Project successfully sequenced the first genome less than ten years ago and cost roughly $500 million to $1 billion. Advances in sequencing technology puts Moore's Law to shame: "In the last four to five years, the cost of sequencing has been falling at a rate of tenfold annually, according to George M. Church, a Harvard geneticist. In a recent presentation in Los Angeles, Dr. Church said he expected the industry to stay on that curve, or some fraction of that improvement rate, for the foreseeable future." The old way of doing things was laborious. The new way involves "a 'DNA transistor,' which it hopes will be capable of reading individual nucleotides in a single strand of DNA as it is pulled through an atomic-size hole known as a nanopore. A complete system would consist of two fluid reservoirs separated by a silicon membrane containing an array of up to a million nanopores, making it possible to sequence vast quantities of DNA at once...[the goal is to build a machine that could sequence] an individual genome of up to three billion bases, or nucleotides, 'in several hours.' "

UK Asylum Seekers: Let The Right Ones In

filthy light thief — Wed, 30 Sep 2009 09:54:02 -0800

The Home Office, the UK government department responsible for immigration control, has initiated a program to test the DNA from of potential asylum seekers in an attempt to confirm their true nationalities. The initial program is a six-month pilot limited to claimants arriving from the Horn of Africa. The program, currently using forensic samples provided on a voluntary basis, could potentially expand to other nationalities if successful. The Home Office spokeswoman said ancestral DNA testing would not be used alone but would be combined with language analysis, investigative interviewing techniques and other recognized forensic disciplines, but many are decrying the "deeply flawed" program, from refugee support groups to scientists in the genetic forensics fields (via). Sandy Buchan, of Refugee Action:

Many of those who seek asylum are two or even three generations removed from the country of origin of their parents and grandparents, and are fleeing areas other than the nation of their birth. A Zimbabwean farmer fleeing persecution may possess the DNA of British relatives; would they be denied asylum on that basis?

Alec Jeffreys of the University of Leicester, who pioneered human DNA fingerprinting:

The Borders Agency is clearly making huge and unwarranted assumptions about population structure in Africa; the extensive research needed to determine population structure and the ability or otherwise of DNA to pinpoint ethnic origin in this region simply has not been done. Even if it did work (which I doubt), assigning a person to a population does not establish nationality - people move! The whole proposal is naive and scientifically flawed.

See also: Science Insider follow-up post and further reactions from experts in genetic forensic analysis.

Molecular Visualizations of DNA

It's Raining Florence Henderson — Wed, 23 Sep 2009 14:48:54 -0800

Molecular Visualizations of DNA

" They that die by famine die by inches." -- Matthew Henry

orthogonality — Mon, 07 Sep 2009 18:41:37 -0800

The winter of 1944–45 is known as the ‘Hunger Winter’ in The Netherlands, which was occupied by the Germans in May 1940. Beginning in September 1944, Allied troops had liberated most of the South of the country, but their advance towards the North came to a stop at the Waal and Rhine rivers and the battle of Arnhem. In support of the Allied war effort, the Dutch government in exile in London called for a national railway strike to hinder German military initiatives. In retaliation, in October 1944, the German authorities blocked all food supplies to the occupied West of the country. Despite the war, nutrition in The Netherlands had generally been adequate up to October 1944. Thereafter, food supplies became increasingly scarce. By November 26, 1944, official rations, which eventually consisted of little more than bread and potatoes, had fallen below 1000 kcal per day, and by April 1945, they were as low as 500 kcal per day. Widespread starvation was seen especially in the cities of the western Netherlands. Food supplies were restored immediately after liberation on May 5, 1945.

But for many, who weren't even born when it started, the hongerwinter continues. Why? In part because "certain environmental conditions early in human development can result in persistent changes in epigenetic information" via DNA methylation. Epigenetics seems like a little bit of Lamarckism: environmental effects on a parent -- or even a grandparent -- can be passed to offspring, even without permanent changes to DNA. (previously)

On specialization in biology

dhruva — Wed, 22 Jul 2009 15:18:24 -0800

An Outsider's View "Over the past fifty years, factions of biologists have had a complex relationship. Some scientists have continued to carry out relatively traditional natural history work, with little need to delve into molecular (or computational) biology. Others have given little attention to natural history, focusing their efforts instead on deciphering the complexities of a membrane channel, or building new algorithms for identifying open reading frames. In some cases, biologists have bridged this divide, and the result has been a fruitful collaboration. But in other cases—such as the DNA studies on whales and hippos—one group moves into the other's traditional territory, sparking new conflict."[via]

DNA Not The Same In Every Cell Of Body

GuyZero — Thu, 16 Jul 2009 16:13:31 -0800

DNA Not The Same In Every Cell Of Body. "...calls into question one of the most basic assumptions of human genetics: that when it comes to DNA, every cell in the body is essentially identical to every other cell... if it turns out that blood and tissue cells do not match genetically, these ambitious and expensive genome-wide association studies may prove to have been essentially flawed from the outset"

G T C A

shadytrees — Thu, 16 Apr 2009 06:55:51 -0800

I can build DNA / I can be a big star (previously) (via the filter)

The Sins of your Fathers

protorp — Wed, 18 Mar 2009 09:57:07 -0800

Familial genetic profiling of law enforcement DNA databases has already been used to succesfully establish both guilt and innocence. Legal and moral questions on these expanded techniques abound and are comprehensively explored by a speaker at a recent FBI symposium on the topic. In the author's words, scenarios previously limited to movies like Minority Report are unfolding quietly, before most of us have thought about the consequences. (Via)

cluck cluck cluck BAWK! ROAR!!

Pants! — Sun, 15 Mar 2009 11:03:28 -0800

When and if the dinochicken is created, Horner looks forward to bringing it out on a leash during lectures. (book)

DIY DNA research

jacalata — Mon, 02 Feb 2009 04:29:15 -0800

Hugh Reinhoff has sequenced his daughters DNA at home attempting to diagnose her unique genetic mutation. Although most parents don't have his background, he also started a website to bring together the parents of children with undiagnosed disorders, and doctors who are interested in the area. At least one family has found their answers through the community already.

Jurrassic World

Brandon Blatcher — Thu, 20 Nov 2008 19:56:33 -0800

We get you real woolly mammoth, very cheap, good quality.

The gene is in an identity crisis

homunculus — Tue, 11 Nov 2008 19:30:39 -0800

Now: The Rest of the Genome. "Only 1 percent of the genome is made up of classic genes. Scientists are exploring the other 99 percent and uncovering new secrets and new questions."

Darwin, extended

digaman — Tue, 11 Nov 2008 18:50:28 -0800

The "blind watchmaker" may not be as blind as we thought. A team of scientists at Princeton University discovers that organisms are not only evolving, they're evolving to evolve better, using a set of proteins to "steer the process of evolution toward improved fitness" by making tiny course corrections.

Personal Genome Project

thatbrunette — Mon, 20 Oct 2008 18:20:31 -0800

Volunteers from the general public working together with researchers to advance personal genomics. 10 volunteers, among them noted author and cognitive psychologist Stephen Pinker, have open sourced (so to speak) their genetic information. The belief is that current privacy issues surrounding genetic information is leading to a decline in research. With a hoped for 100,000 participants the idea is to give a boost to medical research involving the human genome. Pinker and the 9 other volunteers have posted up their medical history, and will add information such as tastes and preferences, ethnic backgrounds. Future volunteers will do the same, along with photographs, allergies- even television habits. Want to join?

It's not the economy, stupid.

scodger — Mon, 29 Sep 2008 00:11:17 -0800

"You know, we spent $3 million to study the DNA of bears in Montana. I don't know if that was a criminal issue or a paternal issue..." (previously) The infamous bear study bought up by McCain in the first debate is one of his favourite pork barrel examples, but little actual information is given about the study. Here is the website giving details about the project, with more info, a quick fact sheet and a podcast. This is one of the rare times when a candidate will air an opinion on science in a popular setting.... However, several websites have been trying to get into the details of the candidates policies on science and technology. The science debate (previously) looks dead in the water, but they did manage to get the candidates to answer 14 questions by email. Nature, a leading scientific journal, has a special section comparing the candidates scientific credentials and a section of questions that were answered by Obama but not responded to by McCain. Key quote from Obama "I believe in evolution, and I support the strong consensus of the scientific community that evolution is scientifically validated." A more popular version is "geek the vote" from popular mechanics. McCain has gained praise for promising to introduce a science advisor, but with 71 Nobel prize winners endorsing Obama and his science plan, it is clear where the consensus lies.

Fred, Barney and Betty Pending

Marisa Stole the Precious Thing — Mon, 22 Sep 2008 12:04:31 -0800

Meet Wilma, the first model of a Neanderthal based in part on ancient DNA evidence. The findings indicate that at least some Neanderthals had red hair, pale skin, and even freckles, adding to the relatively recent evidence that Neanderthals did not interbreed with humans (previously), might have been outbred into extinction by Homo sapiens, and were probably not as stupid as we thought.

Small tweak to DNA may have given us our unique hands

homunculus — Sun, 07 Sep 2008 10:35:36 -0800

Fingering What Make Us Human: Did a gene enhancer humanise our thumbs?

Down

chuckdarwin — Fri, 08 Aug 2008 18:08:33 -0800

The Genius of Charles Darwin Warning: Dawkins haters, click away now. And, yes: eponysterical.

One-woman crime spree

yoyo_nyc — Sun, 20 Jul 2008 16:12:56 -0800

She robs, she injects herself with heroin, she flits across borders like a ghost, she seems to kill with almost professional precision, she leaves clues and bodies – and she has no identity. The suspect, known as the Phantom of Heilbronn, is wanted in connection with 30 crimes in three countries, including six murders and dozens of robberies. Police has no idea what she looks like, they do not know how old she is, but they have one big clue - her DNA. Just today, a Metafilter post was about how reliable DNA is in identifying suspects. A one-woman crime spree? Maybe the employees of the company that provides the PCR kits to the police should handle over their DNA to avoid a systematic error?

How reliable is DNA in identifying suspects?

finite — Sun, 20 Jul 2008 12:18:44 -0800

A discovery leads to questions about whether the odds of people sharing genetic profiles are sometimes higher than portrayed. Calling the finding meaningless, the FBI has sought to block such inquiry.

The Ghost of Bobby Dunbar

smoothvirus — Wed, 19 Mar 2008 07:22:07 -0800

Bobby Dunbar was a four year-old boy that vanished in 1912, while on a fishing trip with his family in a Louisiana swamp. For weeks, searchers combed the area looking for him. The lake where he went missing was dynamited. Alligators were captured and had their bellies slit open to see if the body was inside. Nothing was found except a set of child's footprints leading to an old railroad trestle. Eight months later, the police found Bobby in the company of a drifter with a horse-drawn cart. He protested his innocence but was arrested and charged with kidnapping. Another woman came forward and claimed Bobby was, in fact, her son. But she was an unmarried fieldworker, and her claims were dismissed. The crime became a nationwide media event and the boy was returned to his parents, and their hometown held a parade in his honor. Bobby returned to his life. Ninety-one years later, Bobby Dunbar's granddaughter uncovered the truth.

Synthetic life is now just around the corner.

geeknik — Sat, 26 Jan 2008 12:02:22 -0800

Scientists have built the first synthetic genome by stringing together 147 pages of letters representing the building blocks of DNA.

who'se your daddy?

nihlton — Fri, 11 Jan 2008 15:59:44 -0800

Scientists for better PCR
Just mix your template with a buffer and some primers, Nucleotides and polymerases, too.
Denaturing, annealing, and extending. Well it’s amazing what heating and cooling and heating will do. The PCR Song There was a time when to amplify DNA, You had to grow tons and tons of tiny cells.

Then along came a guy named Dr. Kary Mullis, Said you can amplify in vitro just as well.

Just mix your template with a buffer and some primers, Nucleotides and polymerases, too.

Denaturing, annealing, and extending. Well it’s amazing what heating and cooling and heating will do.

PCR, when you need to detect mutations. PCR, when you need to recombine. PCR, when you need to find out who the daddy is. PCR, when you need to solve a crime.