A team of South Korean researchers has achieved a major scientific breakthrough, successfully cloning a human embryo by implanting a human somatic cell into a human egg and subsequently extracting stem cells.

The Korean scientists also announced that they had successfully transformed the embryonic stem cells into neurons, another scientific first in genetic research.

The accomplishment, which will be detailed in Friday's edition of the journal, Science, heralds a significant step toward curing human diseases by replacing tissues with genetically modified material.

The research team from Seoul National University, led by Prof. Hwang Woo-suk, said it was able to succeed thanks to having access to unfertilized eggs donated by South Korean volunteers.

The team transplanted the somatic cells into those donated egg cells after extracting nuclei from the eggs.

It is hoped that the extraction of embryonic stem cells, known as therapeutic cloning, will eventually provide cures for diabetes, Parkinson's, Alzheimer's and other diseases.

Stem cells are known to be transformed into the more than 210 types of cells and organs of the human bodies, and hold out the tantalizing possibility of one day achieving regeneration of damaged organs or tissue.