Human Cloning

Reproductive Cloningthe benefits of embryonic cloning

What is reproductive cloning?Cloning is the splitting of gametes into daughter cells consisting of the exact same genes. Essentially, a population of almost identical individuals is created from a single set of genes from a single organism. Favourable traits become common throughout a populationMutation is lessened due to the inactivity of natural selection

The Short History of CloningThe concept of cloning was demonstrated in 1952, using tadpolesThe first instance of mammalian cloning was successfully carried out in 1997, resulting in the birth of Dolly, a sheep

Methods of CloningIn order to clone, three methods are currently knownThe simplest method is artificial embryo twinning. This method replicates the natural process in which identical twins are formedSomatic Cell Nuclear Transfer (SCNT for short) is a method in which a genetic replica of a living adult is formed using somatic cells These methods have a fairly low success rate; Dolly was the only embryo to continually grow and mature into a fetus out of 227 experimental embryos

Artificial Embryo TwinningArtificial embryo twinning or splitting is a relatively cheap form of cloningIt mimics the natural splitting of eggs, which results in identical twins, triplets, etc.

Blastocyst is held in position by a micropipette, and bisected with a surgical blade

Somatic Cell Nuclear Transfer

Therapeutic CloningIn 2001, Advanced Cell Technologies (ACT) in Massachusetts, announced the first successful cloning of embryosThe nuclei of embryos collected from a womans uterus were extracted using a needle no wider than 2/10,000th of an inchA skin cell was inserted via nuclear transfer to act as the nucleusIonocymin was used to stimulate division.Stem cells could be harvested from the egg after five days of division (blastocyst stage)

Human CloningAmerican Association for the Advancement of Science (AAAS) and numerous groups have acted against human cloning due to ethical reasonsCloning has a very low success rate, and the embryos that do mature may result in offspring with serious defectsMany believe that a cloned human would be dehumanized

Cloning in Food ProductsIn 2001, the FDA conducted research regarding the safety of meat from cloned livestock In 2008, the FDA approved cloning as a source of meat productionDue to herds sharing identical genomes, livestock of better quality is produced

ControversyCloning is seen as unethical by manyWhether it be humans or frogs, experimental reproduction is considered unjust Cloning of humans is illegal due to the apparent immorality in controlling human birth

ConclusionMore efficient methods should be researched, and not practised with larger mammalsEmbryos should be cloned for further understanding

Sourceshttp://serendip.brynmawr.edu/biology/b103/f00/web1/tamang.html http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1476349/ http://www.ornl.gov/sci/techresources/Human_Genome/elsi/cloning.shtml http://www.ama-assn.org/ama/pub/physician-resources/medical-science/genetics-molecular-medicine/related-policy-topics/stem-cell-research/human-cloning.page http://www.humancloning.org/benefits.php http://es.houstonisd.org/riveroakses/exhibition09/cloning_files/page0011.htm

Picture SourcesDolly - http://www.roslin.ed.ac.uk/public-interest/dolly-the-sheep/a-life-of-dolly/AET - http://www.biolreprod.org/content/66/5/1449.full SCNT - http://www.biotechnologyonline.gov.au/popups/img_scnt.html Stem Cells - http://www.scientificamerican.com/article.cfm?id=embryos-survive-stem-cell-harvest