Tetra (monkey) facts for kids

Tetra was a special rhesus macaque monkey born on October 12, 1999. She was created using a science method called "embryo splitting". This made her the first "cloned" primate (a group of animals that includes monkeys, apes, and humans) made by "artificial twinning."

A team of scientists led by Professor Gerald Schatten at the Oregon National Primate Research Center created Tetra. Her birth was a big step in understanding how to create identical animals.

How Was Tetra Created?

Tetra was made using a process called embryo splitting. Imagine a very early baby animal, called an embryo, that is just starting to grow. This embryo has cells that are dividing. In Tetra's case, when the embryo had eight cells, scientists carefully split these cells apart.

The Splitting Process

• The eight-cell embryo was split into four smaller groups of cells.
• Each of these groups then started to grow like a new, tiny embryo.
• This method is like how identical twins are formed naturally, but it's done in a lab. That's why it's called "artificial twinning."

This was the first time scientists successfully used this splitting method in monkeys. It had been used before in farm animals like cattle.

From Embryo to Birth

After the splitting, only two of the four tiny embryos grew enough to be placed inside a mother monkey. Tetra was the only one of these two that was born successfully. She arrived after about 157 days, which is how long rhesus macaques are usually pregnant.

The world learned about Tetra on January 13, 2000, when she was four months old. Scientists hoped that creating identical primates like Tetra would help them learn more about human health and diseases. They thought it could lead to new medical treatments.

Different Ways to Clone

The method used to create Tetra was different from the one used to clone Dolly the sheep. Dolly was made using a technique called nuclear transfer. This involves taking material from an adult animal's cell and putting it into an empty egg cell. Tetra's method was simpler, like creating identical twins.

ANDi: Another Special Monkey

The year after Tetra was born, the same team of scientists created another rhesus macaque named ANDi. ANDi was special because he was the first monkey to be genetically modified. This means scientists changed some of his genes. They added a gene from a jellyfish to his cells. This made his cells glow under a special microscope, which helped scientists study them.

See also

• ANDi
• List of individual monkeys
• List of cloned animals