Cytoplasmic Hybrid Embryos
Why does Genetic Alliance UK support cytoplasmic hybrid embryo research?
We believe that the cytoplasmic hybrid technology which we supported with our joint letter with the Association of Medical Research Charities (AMRC) sent to the Prime Minister on 5th April 2007, and signed by 223 charities, is promising research that deserves to be explored by the scientific community. Work with cytoplasmic hybrid embryos has significant potential to deliver cures and treatments for patients suffering from currently intractable or incurable conditions.
The technology allows researchers to create embryos without using the valuable and scarce resource of donated human eggs. Research on embryos created by this process is subject to all the regulations that other forms of embryo research must observe. This is legal research democratically approved by the British Parliament, and approved by an ethics committee.
We believe that this work, deserves to continue because of its enormous potential to help people whose daily lives are compromised by serious medical conditions. We recognise that this research creates moral and ethical concerns for some people. A substantial majority of the UK population have endorsed its legitimacy whenever opinion has been canvassed on this issue.
What are cytoplasmic hybrid embryos?
An egg cell from an animal, normally a cow or rabbit, is used in the process. The cell's nucleus is removed, leaving only a tiny trace of animal DNA (inside some of the cell's machinery). The nucleus from a human cell is then placed in the cell. The cell is then stimulated to divide into a embryo. After a few days, stem cells can be taken from the embryo and used to study diseases.
Before this technology was proposed all embryos for use in research were created using a human egg cell. These cells must be donated by women using an invasive process that is not without risk to the woman donor. Because the overwhelming majority of donated eggs are used for IVF, numbers available for research are low. This scarcity of human eggs for research slows down research. The use of cytoplasmic hybrid technology should allow more research, and therefore foster progress, without having to rely on donated human eggs.
What aren't cytoplasmic hybrids?
Cytoplasmic hybrids are not "true hybrids". Hybrids are embryos or animals that have a mixed genome from more than one species. (An example of a hybrid would be a mule, which is a cross between a horse and a donkey.)
Cytoplasmic hybrids are not chimeras. Chimeras are embryos or animals that contain cells from more than one species (e.g. the mermaid, which is half human, half fish).
Currently there are some limited applications of these technologies which are known to be beneficial (e.g. "hamster test", and Down's mouse). These and any similarly beneficial applications should continue to be permitted.
True hybrids and chimeras are what people understand to be human-animal hybrids. Cytoplasmic hybrids are not human-animal hybrids nor are they "half animal half human". Cytoplasmic hybrids are considered to be legally "human" in UK law and are therefore under the jurisdiction of the Human Fertilisation and Embryology Authority (HFEA).
Why is this important for patients?
The objective of the use of cytoplasmic hybrids is to create stem cells. Once you have harvested a stem cell, it can be made to divide and produce more identical stem cells, this is known as a stem cell line.
Stem cell lines are a very powerful way of researching the causes of and cures for many serious diseases. If we can create a stem cell line with the genetic disorder that causes a certain disease, we can see how that disease develops and potentially create mechanisms for disrupting the disease process.
Stem cells can be persuaded to specialise into different cell types e.g. nerve cells, or muscle cells. We can us this property to see how the disease affects these cells. Once we understand the mechanism of the condition, potential treatments and cures can be developed.