Embryonic stem cells can develop into any kind of tissue in the body, including nerves, muscle, organs and bone. Depending on which chemical signals they are given. Adult stem cells found in bone marrow, umbilical cords, the brain, and other parts of the body can also be used to make new tissue. Regulations relaxed In December 1998 two research watchdogs, the Human Genetics Advisory Commission and the Human Fertilisation and Embryology Authority, recommended that the law should be relaxed to allow the use of early-stage human embryos for stem cell research. Under the 1990 Human Fertilisation and Embryology Act embryos up to 14 days old can already be used for research into specific areas such as fertility, contraception, miscarriage and congenital disorders.
Therapeutic cloning offers the possibility of overcoming the problem of transplant tissue rejection.
An embryo cloned from a patient would yield stem cells which could be sued to grow tissue compatible with the patient. Therapeutic cloning will also allow scientists to explore the biological mechanisms involved in the growth and development of human cells.