Uses of Animal Cloning (OCR A Level Biology): Revision Note

Uses of Animal Cloning

Arguments for animal cloning

• Embryo cloning is well accepted and noncontroversial in the field of livestock farming

• Many animals with desirable characteristics can be cloned, ideal for maximising agricultural output eg. milk yield in cattle

• Cloning can also:

  • Remove less desirable characteristics from the gene pool over time, much in the way that selective breeding has done

  • Help preserve endangered species, ahead of possible reintroduction of those species to the wild

  • Provide regenerated organs for patients suffering from degenerative disease. Such organs will be a direct genome match to the patient so would have no risk of rejection by the immune system

Arguments against animal cloning

• The process of somatic cell nuclear transfer (SCNT) is very hit-and-miss

  • It took hundreds of unsuccessful attempts to clone Dolly the sheep

• There are also unknown long-term effects of the cloning process

  • Subsequent cloning attempts have led to a high number of early deaths and genetic abnormalities in the clones

• Some cloned animals that survive birth and infancy tend to grow abnormally large (Large Organ Syndrone - LOS)

  • LOS can cause breathing and circulatory problems in adult animals

  • Other clones have developed abnormalities in other large organs eg. kidneys, or in their immune systems

• No precise 'cause and effect' has been ascribed to the cloning process, but research has indicated that cloning disrupts the normal mechanisms or regulation of gene expression

• Cloning destroys embryos which could in theory develop into a healthy adult animal - the argument put forward by groups such as Pro-Life

• For these reasons, animal cloning has not gathered as much pace as many scientists thought it would