Month: January 2013 (page 2 of 5)

dna data storage

DNA, RNA and their bases

DNA, RNA and their bases

In the January 23rd edition of Nature a team of scientists report using DNA to store poems, a picture and a recorded speech. From Science News:

Led by Nick Goldman, researchers from the European Bioinformatics Institute in England began by converting the five files into bits (technically, “trits” — they used a triplet code comprising zero, one and two). Then they translated that code into one made of As, Cs, Gs and Ts, the “letters” of DNA. So TAGAT replaces the “T” that begins line two of Shakespeare’s sonnet 18: “Thou art more lovely and more temperate.”  The team also incorporated a way to index the data — sort of a DNA version of the Dewey Decimal System — and an error correction code to keep the data clean.

Then the researchers sent their code to the instrumentation company Agilent Technologies in Santa Clara, Calif. There scientists read the code and used it to build millions upon millions of DNA molecules, which they sent back to the researchers via FedEx in a test tube inside a cardboard box.

When the test tube, about the size of a pinkie finger, arrived, Goldman and his colleagues sequenced the DNA, the same way researchers read the DNA of organisms, reconstructing the original files. The translation from data to DNA and back was free of errors, says Goldman.

DNA storage offers the potential of holding vastly more data in a smaller amount of space. It might also potentially be cheaper as the cost of DNA synthesis and sequencing continues to become less costly.

dogs, wolves and carbs

Domesticated dog breeds evolved long ago from the wolf. In a study published in Nature, researchers examined differences in the genomes of modern domesticated breeds and wolves and made some interesting discoveries. They expected differences in the nervous systems since the species behave differently. They also found many differences in genes effecting metabolism, especially digestion of carbohydrates. Domesticated breeds digest starches much better than wolves.  From Science News:

The new study focuses on genetic differences between 60 dogs representing 14 breeds and 12 wolves from around the world. Those changes, the researchers reasoned, could identify genes that were important in separating dogs from wolves.

The researchers determined the genetic makeup of groups of dogs and compared the results to those from wolves, concentrating on parts of the genetic instruction book that differ between the two species. As they had expected, the researchers uncovered differences in many genes relating to the brain. But the search also revealed lots of genes involved in starch digestion and metabolism, and in the use of fats. Dogs, the team found, have more copies than wolves do of the AMY2B gene, which produces an enzyme that breaks starch into easily digestible sugars.

Other genetic variants seem to contribute to dogs’ increased ability to convert a sugar called maltose to glucose, the sugar that cells prefer to burn for energy. Yet other genetic changes improve dogs’ ability to move glucose into their cells. Combined, the tweaks alter dogs’ metabolism so they can get more energy out of a carbohydrate-rich diet than wolves can, the researchers conclude. The scientists confirmed the effect of the genetic variants by identifying biochemical differences in starch metabolism in blood and tissue samples from dogs and wolves.

neanderthals cloning, continued

Tyler Cowen considers reasons why we wouldn’t want to clone neanderthals. There are many ethical questions on how we would deal with the offspring:

Then ask yourself some basic questions about Neanderthals: could they be taught in our schools?  Who would rear the first generation?  Would human parents find this at all rewarding?  Do they have enough impulse control to move freely in human society?  How happy would they be with such a limited number of peers?  What public health issues would be involved and how would we learn about those issues in advance?  What would happen the first time a Neanderthal kills a human child?  Carries and transmits a contagious disease?  By the way, how much resistance would the Neanderthals have to modern diseases?

What kinds of “human rights” would we issue to them?  Would we end up treating them better than lab chimpanzees?  Would they be covered by ACA and have emergency room rights?

We don’t know the answers here, but I would expect to run up against a number of significant fails on these issues and others.

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