Tomorrow’s world
Walter Isaacson and Henry Greely probe the power and peril of CRISPR gene-editing MIT Press; 400 pages; $27.95 and £22.50
The Code Breaker. By Walter Isaacson.
Simon & Schuster; 560 pages; $35 and £30
W
HAT THE transistor once was to electronics, so
CRISPR gene-editing is to biotechnology today. It changes the field from something interesting but clunky, and of restricted application, into a game of infinite possibility that almost anyone can play. Transistors led to computer chips and the youthful entrepreneurs of the Homebrew Computer Club in Silicon Valley. Similarly,
CRISPR editing has let a new generation of would-be billionaires explore ideas that range from systematising the search for the proteins targeted by drugs, to breeding pigs that might act as organ donors for transplants.
Credits: Cover image courtesy of Pantheon
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In 1929, astronomer Edwin Hubble, using data from the Mount Wilson Observatory in California, found that the universe is expanding. This was “probably the most important cosmic discovery of all time,” writes Alan Lightman in his new book, “Probable Impossibilities: Musings on Beginnings and Endings.” Certainly it is among the most thought-provoking.
Hubble’s discovery complicates how we grasp space and time. Can you picture a universe that expands infinitely? And if it is expanding, it must have had a starting point in time. But what existed before that, and how did things get started?
For Nobel laureate Jack Szostak, the biggest question in science today is fundamental: What is the origin of life?
Szostak, a professor of genetics at Harvard University, has dedicated his lab to piecing together the complex puzzle of life’s origins on Earth.
The story takes us back billions of years and may provide answers to some of our most mysterious questions: Where did we come from and are we alone in the universe?
“We all want to know one way or another how we came to be here,” says Szostak.
“If you just look around at life and the world, it’s so amazing and varied and beautiful and it’s so different from everything that’s inanimate. It just raises the question of: How did this difference arise and how did it lead to us?”
Organisms with linear chromosomes have to solve the problem that DNA replication makes them shorter. This is due to the fact that DNA polymerase can only add bases to the terminal 3 -OH of a DNA chain. The DNA replication initiation complex uses RNA primers to provide the initial 3 -OH and to initiate lagging strand synthesis. While one strand can be copied all the way to the end of a chromosome, the other, lagging strand, must be primed at short intervals in order to provide a 3 OH group for DNA polymerase as the replication fork advances through a chromosome. The problem at the end of a chromosome then is that the lagging strand has nothing for the primer to bind to. Without some kind of solution, each replication cycle would result in a shorter chromosome.
Evolutionary biology long ago solved the philosophical conundrum what came first, the chicken or the egg? by showing that eggs came long before chickens.
But more relevant to evolution is the mother molecule that led to the formation of life. What is it and how did it replicate itself?
RNA may be the answer to the first question, because it has more flexibility in how it recognizes itself than previously believed. The finding might change how we picture the first chemical steps towards replication and life.
Today, plants, animals and other organisms reproduce by making copies of their DNA with the help of enzymes and then passing the copies onto the next generation. This is possible because genetic material is made of building blocks or bases A, T, U, G and C that pair up in a specific way. A pairs with T (or U in RNA), and G pairs with C. This rule is called Watson-Crick base pairing, named after the scientists who were credited with solving DNA s structure. But befo