What is it?
This is a scientific laboratory technique for creating an ovum with a donor nucleus. It can be used in embryonic stem cell research or in regenerative medicine which is more commonly known as therapeutic cloning.
A very famous example of somatic cell nucleotide transfer
Dolly the sheep is the most famous case of somatic cell nucleotide transfer. Dolly was a huge step forward for science as cloning adult cells is much more challenging than cloning embryonic cells, as these have the ability to differentiate into any type of cell. Dolly was the only living survivor out of 277 sheep that were trialled. This is how it all went down:
Udder cells were taken from a donor female sheep. These cells were cultured in a low nutrient medium to turn off in a certain way their genes and make them dormant. Meanwhile, unfertilized egg cells were taken from another sheep. The nucleus was removed from each egg cell, obviously using a micropipette. The egg cells without nucleus were then fused with the other cells using power from electricity. The embryos were implanted into another sheep who then became the surrogate mother where the fused cells developed like zygotes and became embryos and eventually, Dolly the Sheep.
This can break it down for you:
It is important to note that Dolly was genetically identical to the sheep that the udder cells were donated from, she therefore developed many problems at a young age, such as arthritis and sadly passed away at the age of 7. It is important to note that sheep usually live 10 to 12 years, which renders the question how effective this cloning truly was?