July 23, 2010

Cloning Success – 1998

On this date in 1998 the “Yana team” (Ryuzo Yanagimachi and his research team from the University of Hawaii) published about their new technique for cloning mammals from adult cells. The team cloned more than 50 identical mice representing three different generations. The paper was published in the respected journal Nature.

Dolly the sheep, the first mammal successfully cloned, is perhaps the most famous clone as well.

Many plants and most animals reproduce sexually, which means that a male fish and a female fish together produce baby fish, male birds and female birds together make fertilized eggs, male plant parts and female plant parts work together to create seeds, and so forth. In sexual reproduction, there are two parents, each passing on half of his or her genetic material, and so almost every baby plant or animal ends up being unique. (Of course there are exceptions such as identical twins.)

Some organisms reproduce asexually. Bacteria, protists, many fungi and plants, and some animals are able to create offspring with just one parent―and the offspring has pretty much the same genes as that parent. (Again, there are exceptions such as mutation and “lateral gene transfer.”)

Cloning is a lot like asexual reproduction. Generally speaking, genetic material (inside a nucleus) is taken from a single individual and is inserted into an egg that has no nucleus. If the cell begins dividing, it is transferred to a surrogate mother. Another artificial cloning method involves deliberately creating identical twins by dividing a cell at a crucial state of development―and both pieces go on to create identical organisms.

There is a lot of controversy over cloning―especially over cloning humans―but actually farmers and gardeners have been cloning plants for centuries or even millennia! One could say that it is unfair to use the word cloning for processes such as grafting, but the word was used in horticulture first!

For more on cloning, check out “Eureka Science.”

For more on the ethics of cloning, here is an old Salon interview. (Note: it is more than ten years old. Nevertheless, I found it interesting.)