Before starting with cloning techniques, first of all; what are clones?

Clones are two or more organisms with identical genetic make-up derived, by ASEXUAL REPRODUCTION, from a single common parent or ancestor, such as identical twins.



Embryo splitting involves dividing an eightcell embryo into single cells or BLASTOMERES. Transferring two of these blastomeres into an empty ZONA PELLUCIDA creates an embryo. Once the embryo reaches the BLASTOCYST stage, EMBRYONIC STEM CELLS may be collected from the INNER CELL MASS for use in further research. A second option is to implant the embryo in a surrogate mother, allowing it to develop fully. Offspring produced by embryo splitting will be identical clones of one another if the embryo from which they were derived is produced by fertilising an egg with sperm, the offspring will not be identical to either of their genetic parents. This technique has been used successfully to create non-human primate clones, but somatic cell nuclear transfer is the most commonly used cloning technique.

In Intra-species cloning the nucleus of a somatic cell is taken from one organism and placed in an enucleated egg from another member of the same species. This method was used to produce the first cloned animal, Dolly the sheep. It has subsequently been used to clone other species.

 Inter-species cloning is more controversial than intra-species techniques because the nucleus of a somatic cell from one organism is transferred to an enucleated egg from a different species. Scientists have used this technique to clone human cells by placing the nucleus of a human somatic cell in an enucleated egg from a cow. The hybrid cells that were produced were able to divide, but they were not permitted to develop to the blastocyst stage.

Here you have two videos that can explain you a little bit better the cloning techniques.

There are different types of cloning, the most important are the following ones.

Therapeutic cloning involves using SCNT to create embryonic stem cells that have a genome identical to the cell donor’s. The embryo that is created (and from which the cells are harvested) is not implanted into a surrogate mother. It will not therefore be used to create another whole organism.

 Reproductive cloning uses SCNT to create embryos that are implanted into a surrogate mother and brought to full term. The organisms that result will be clones of the cell donor, e.g. Dolly the sheep.

Gene therapy is the insertion of genes into an individual’s cells and tissues to treat diseases, such as hereditary diseases where deleterious mutant alleles are replaced with functional ones. Although the technology is still in its infancy, it has been used with some success. Scientific breakthroughs continue to move gene therapy toward mainstream medicine.


 With the information that you hve above draw a diagram showing the different stages of cloning technique and explain each stage.

Post creators: Izarbe Jarque e Irene Layunta