Inherent Defects Cast Doubt on Touted Benefits of Human Research Cloning
A review of all the cloned animals in the world, conducted by Ian Wilmut, creator of Dolly the sheep, finds that every one of them is in some way defective. This fact raises serious questions for the therapeutic use of embryonic stem cells derived from cloning.
Science has only a very limited understanding of the system of genetic signals (called “imprinting”) that work to guide the earliest stages of embryonic development. This system does not appear to function normally in the cloning process, thus producing genetic defects and abnormal development. Because of these defects, there is a strong possibility that these cells will not develop in the ways that are being touted and they may in fact end up being poor sources to develop various tissue types for treating diseases.
This is why alternatives to cloning, such as the use of adult stem cells derived from the patients themselves, appear more promising, because many of the controlling factors are already known and can be easily manipulated.