Clipmarks | rmowery's genetics collection

'DNA computer' is unbeatable at tic-tac-toe

Tue, 17 Oct 2006 21:23:18 GMT

clipped by: rmowery

Clip Source: www.newscientisttech.com

'DNA computer' is unbeatable at tic-tac-toe

Tom Simonite

NewScientist.com news service

10:35 17 October 2006

A computer that uses strands of DNA to perform calculations has mastered the game tic-tac-toe.

MAYA-II, developed by researchers at Columbia University and the University of New Mexico in the US, uses a system of DNA logic gates to calculate its moves.

A DNA logic gate consists of a strand of DNA that binds to another specific input sequence. This binding causes a region of the strand to work as an enzyme, modifying yet another short DNA sequence into an output string.

Scientists have already developed DNA computers capable of various similar simple calculations. But the researchers behind MAYA-II say their design should prove particularly useful for exploring ways to identify the genetic markers associated with certain diseases.

Another level

A human plays MAYA-II by adding a DNA sequence that represents their chosen move at a particular point in the game. This is added to all 8 wells that correspond to the outer squares on a tic-tac-toe grid. One limitation of the system is that the human player must always go second, after the centre square has been filled by the machine.

The previous version of MAYA, unveiled in 2003, was even more limited. The human opponent’s first move was restricted to one of two squares (see First game-playing DNA computer revealed).

Tags: dna, dna computing, bio-computing, bitech, dna computation, tic-tac-toe

Early to bed, early to rise: Sleep Genetics

Thu, 21 Sep 2006 05:24:23 GMT

clipped by: rmowery

Clip Source: www.eurekalert.org

Early to bed, early to rise

Genetics of the morning lark

In an upcoming G&D paper, a team of German scientists presents a genetic basis for understanding human morning lark behavior. Dr. Achim Kramer (Charité Universitaetsmedizin Berlin) and colleagues have uncovered a genetic cause for the human familial advanced sleep phase syndrome (FASPS), which causes people to both go to sleep and wake up very early.

"Being a morning lark or a night owl is something encoded in people's genes and we here made substantial progress to uncover the molecular basis for that," explains Dr. Kramer.

FASPS is a dominantly inherited circadian rhythm disorder in which patients' inborn biological clock (or circadian clock as it is known by scientists) runs ahead of normal. Circadian clocks are found in organisms ranging from bacteria to humans. They keep our bodies' daily activities, like sleeping and eating, on a roughly 24 hour schedule, or period. FASPS patients' periods are about 4 hours advanced, causing the patients to retire at 6 or 7pm and rise by 4am. In 1999, it was discovered that a mutated gene, called PERIOD2 (PER2) is mutated in many cases of FASPS.

Dr. Kramer and colleagues mapped phosphorylation sites on the PER2 protein. They identified 21 sites, one of which (Serine 659), was implicated in FASPS. By monitoring the bioluminescence cycles of cell lines, the researchers demonstrated that mutation of Serine 659 causes a shortening of the luminescence period and recapitulates the FASPS phenotype. The researchers determined that the mutated form of Serine 659, which does not get phosphorylated, leads to PER2's destabilization and earlier clearance from the cell nucleus.

Tags: sleep, science, genetics, circadian clock, biology

Did a Virus make you smart?

Mon, 04 Sep 2006 04:53:53 GMT

clipped by: rmowery

Clip Source: scienceblogs.com

Category: Books • Evolution • Genetics
Posted on: August 23, 2006 10:58 AM, by Coturnix

Not really a review of Greg Bear's "Darwin's Radio" and "Darwin's Children" but musing (practically SF itself) on the topic of these books (from April 20, 2005):

Did A Virus Make You Smart?

I've been reading science-fiction pretty much all my life. I usually go through "phases" when I hit on a particular author and read several books by the same person. Last year I was in my Greg Bear phase and I have read eight of his books. He is one of those writers who gets better with age: more recent his book, more I liked it.

After I read his last two novels, "Darwin's Radio" and "Darwin's Children" I decided to check on his science - it sounded very good, yet so fantastic at the same time. What I found was a surprise: the real science is really that fantastic! Greg only needed to add a very little twist in order to turn it from fiction into science-fiction. So, here is some of what I discovered (though I am a biologist, this is way out of my area of expertise, so assume this is a lay-person writing).

His is also some of the hardest of hard sci-fi around. He must be a really smart guy - he has a blog, after all! Bear really thoroughly researches whatever area of physics, astronomy, geology or biology he needs for his next novel. At a book reading last year, several people in the audience voiced their difficulties in understanding the science parts of his novels, while they thoroughly enjoyed the characters and plot. As a biologists, I found the science easy to understand, yet riveting anyway.

Tags: pshychology, genetics, science, rna, dna, retrovirus

Move over, guys, here comes lab-made sperm

Wed, 12 Jul 2006 01:43:01 GMT

clipped by: rmowery

Clip Source: newpaper.asia1.com.sg

COULD men one day be redundant in the baby-making process?

Move over, guys, here comes lab-made sperm

July 12, 2006

Some scientists - male, presumably - fear so, after a potential cure for male infertility was discovered.

A Newcastle scientist managed to fertilise ova with sperm grown artificially from stem cells.

While this may be a boon to infertile men, who will now have the chance to 'grow' their own sperm, critics say it may also threaten men's thus-far-crucial role in reproduction, reported The Daily Mail.

But don't panic prematurely. So far, it's been done only with mice.

Tags: biotechnology, lab made sperm, stem cells, sperm