Writing the Book in DNA: Geneticist Encodes His Book in Life's Language

Using next-generation sequencing technology and a novel strategy to encode 1,000 times the largest data size previously achieved in DNA, a Harvard geneticist encodes his book in life's language. Although George Church's next book doesn't hit the shelves until Oct. 2, it has already passed an enviable benchmark: 70 billion copies -- roughly triple the sum of the top 100 books of all time.And they fit on your thumbnail.
That's because Church, the Robert Winthrop Professor of Genetics at Harvard Medical School and a founding core faculty member of the Wyss Institute for Biomedical Engineering at Harvard University, and his team encoded the book,Regenesis: How Synthetic Biology Will Reinvent Nature and Ourselves,in DNA, which they then read and copied.
Biology's databank, DNA has long tantalized researchers with its potential as a storage medium: fantastically dense, stable, energy efficient and proven to work over a timespan of some 3.5 billion years. While not the first project to demonstrate the potential of DNA storage, Church's team married next-generation sequencing technology with a novel strategy to encode 1,000 times the largest amount of data previously stored in DNA.
The team reports its results in the Aug. 17 issue of the journalScience.The researchers used binary code to preserve the text, images and formatting of the book. While the scale is roughly what a 5 ¼-inch floppy disk once held, the density of the bits is nearly off the charts: 5.5 petabits, or 1 million gigabits, per cubic millimeter. "The information density and scale compare favorably with other experimental storage methods from biology and physics," said Sri Kosuri, a senior scientist at the Wyss Institute and senior author on the paper. The team also included Yuan Gao, a former Wyss postdoc who is now an associate professor of biomedical engineering at Johns Hopkins University.

Finally, the Promise of Male Birth Control in a Pill: Compound Makes Mice Reversibly Infertile

Researchers have finally found a compound that may offer the first effective and hormone-free birth control pill for men. The study in the August 17th Cell, a Cell Press publication, shows that the small molecule makes male mice reversibly infertile without putting a damper on their sex drive. When the animals stop taking this new form of birth control, their sperm rebound and they are again able to sire perfectly healthy offspring.

"This compound produces a rapid and reversible decrease in sperm count and motility with profound effects on fertility," said James Bradner of the Dana-Farber Cancer Institute, the lead author of the study.

A male birth control pill hasn't been easy to come by in large part because of the challenge of getting any drug across the blood:testis barrier, where it can reach the sperm-generating cells. That lack of contraceptive alternatives for men is partially responsible for the high rate of unplanned pregnancies. Despite the unsatisfactory options for male contraception, nearly one-third of couples rely on male-directed birth control methods.

More Powerful Supercomputers?

Researchers have created a new type of optical device small enough to fit millions on a computer chip that could lead to faster, more powerful information processing and supercomputers.

The "passive optical diode" is made from two tiny silicon rings measuring 10 microns in diameter, or about one-tenth the width of a human hair. Unlike other optical diodes, it does not require external assistance to transmit signals and can be readily integrated into computer chips.

The diode is capable of "nonreciprocal transmission," meaning it transmits signals in only one direction, making it capable of information processing, said Minghao Qi (pronounced Chee), an associate professor of electrical and computer engineering at Purdue University.

"This one-way transmission is the most fundamental part of a logic circuit, so our diodes open the door to optical information processing," said Qi, working with a team also led by Andrew Weiner, Purdue's Scifres Family Distinguished Professor of Electrical and Computer Engineering.

The diodes are described in a paper to be published online Dec. 22 in the journal Science. The paper was written by graduate students Li Fan, Jian Wang, Leo Varghese, Hao Shen and Ben Niu, research associate Yi Xuan, and Weiner and Qi.