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It’s a simple question with a complicated answer.
Inside almost every cell in your body there is a unique set of instructions called your genome, which is made up of DNA.
It is a kind of manual, setting out many details from the shape of your hands and feet and the colour of your eyes and hair to your preference for sweet or bitter foods. In fact, every living thing on the planet - plants and animals - has its own set of instructions.
Of course, that’s not the whole story. The world around you - and everything that happens to you during your life - helps to shape who you are. But your genome is the important starting point for making you you.
New genome editing tools are changing how science is done at places like the Crick, allowing scientists to alter DNA more quickly, more easily and more accurately.
These tools are improving scientists’ ability to study what different parts of DNA do, how these affect our growth and development, and our chances of developing specific health problems. Genome editing helps research the significance of genetic variants, to treat conditions and diseases, and to understand and alter our environment.
Genome editing technologies hold extraordinary potential to improve human health and the world around us. But using these new tools brings all sorts of important ethical questions and concerns along with them. Which diseases should we try to cure? What is the difference between treating (or avoiding) a genetic condition, and enhancement? How much about ourselves should we change?
How should we use these tools, how should they be regulated, and who should decide?
In Cut + Paste you’re invited to think about these questions, ask your own, and have your say.
The average human being is made of more than 30 trillion cells. These form your skin, bones, brain, and every other bit of your body. And in almost all of your cells there is a copy of your unique instruction manual: your genome. To understand how this manual can be edited by ‘cutting and pasting’, first it’s helpful to know how we are constructed…
What are you made of?
- Your genome is made up of DNA - long chains of chemicals arranged in a sequence that are tightly coiled into a spiral called a double helix. Sections of these chemical sequences are called genes, and they control different elements of your body’s growth and development, and how your body functions.
- Half of your DNA comes from your mother and half from your father - this is why you inherit similarities in the way you look, but also why some diseases or conditions can be passed on from one generation to the next.
- Your body is constantly copying its genome as it grows and replaces cells. Very occasionally, errors occur during the copying process which can lead to diseases such as cancer.
- Each strand of coiled DNA is called a chromosome. Most humans have 46 chromosomes arranged in 23 pairs. Almost every cell type in the body has a full set of these chromosome pairs in its nucleus, the cell’s ‘control centre’.
What makes you you?
- Your genome can influence many things about you from the colour of your hair and the shape of your toes to how likely you are to develop certain diseases. But is there more to you than your DNA?
- There are lots of other factors that can influence how you develop, from the food you eat (or your mother ate while you were in the womb) to how much you exercise; whether you drink or smoke; and the climate that you live in.
- We all ‘enhance’ ourselves to some degree: whether it is through education, using drugs such as caffeine to increase alertness, wearing make-up, working out, or even undergoing surgery to change the body.
What is genome editing?
- Humans have been shaping the genomes of plants and animals for centuries by carefully selecting and breeding certain species that have desirable traits. This has been carried out with animals such as dogs, cattle or sheep, and with plants such as tomatoes, wheat or corn. Genome editing tools allow scientists to introduce faster changes with a wider range of possibilities.
- One of these genome editing tools is called CRISPR (pronounced “crisper”). CRISPR can be programmed to recognize and ‘cut’ a snippet of DNA and ‘paste’ in a new piece. The edit can be made on a very tiny or a much larger section of DNA. This editing process is very useful for scientists trying to work out what certain genes or sections of DNA do. Their discoveries can help in the treatment of diseases such as cystic fibrosis and some cancers, as well as the development of new ways to fight malaria by editing mosquito genomes.
- Today, around 80% of labs at the Crick use new cutting and pasting tools to target and edit specific parts of the genomes of different organisms - including animals, fungi and bacteria. One example used by some labs at the Crick involves genome editing zebrafish. As young zebrafish are transparent, their major organs are very visible, which makes it a really useful model organism for understanding cell development. To identify and highlight specific organs and cell types, genome editing is used to insert light-emitting genes from other organisms, such as jellyfish, into the zebrafish embryo. This means researchers can ‘tag’ particular cells so they emit different coloured light, and they can analyse them more easily and in real time.
- A person’s genome can be edited to treat a specific disease - this is called a ‘somatic’ edit. For example, somatic editing is being trialled to treat people with sickle cell disease. The treatment will not change the genome of any future children they may have. Changes to the genome that can be passed on are carried out on egg and sperm cells or very early embryos, and they are called ‘heritable’ edits. Heritable genome editing is not currently legal in the UK.
- Genome editing tools are advancing all the time and in the future they could allow us to edit the genomes of plants, animals and humans more quickly, easily and accurately than ever before.
Pass It Down
We share all sorts of attributes with our families: some are understood to be the product of inherited genes, like hair type or eye shape. Other traits, like the ability to sing, are thought to be the product of interactions between genes and our environment, upbringing and life experiences. Many other aspects of who we are may be influenced in some way by our genes, but are still not well understood.
Pass It Down invites you to think about your traits, tastes and talents. What have you inherited? What would you hope to pass on?
What tastes would you pass on?
- Sweet tooth
- Spicy foods
- Animal lover
- Sports fan
What traits would you pass on?
- Night owl
- Early bird
- Hair type
- Sense of humour
What talents would you pass on?
- Master chef
- Science whizz
Choose up to six objects from the table that represent what you have inherited and that you would like to pass on, and add them to the ‘gift’. If you want to add your own, use a blank board and one of the pens provided. Take a picture and share on Twitter or Instagram with the hashtag #CutAndPaste.
Sometimes what we inherit includes a genetic variant or condition that we may not wish to pass on. Read more on the other side of this board to explore how genome editing is being trialled, and could be used in the future, when this happens.
Genome editing for treatments
Currently, somatic genome editing treatments (which only affect the body of the person being treated, and not future generations) are being trialled for a number of conditions that are caused by variants in specific single genes. These include blood diseases like sickle cell disease and haemophilia B, some inherited forms of sight loss, leukaemia and several other cancers.
It is not yet possible to use genome editing as a treatment or cure for conditions that can be caused by the combined effect of multiple gene variants, such as heart disease and diabetes.
Genome editing for reproduction
Currently it is not legal in the UK to use heritable genome editing (where the edit would affect all future generations) to alter an early embryo, eggs or sperm to prevent passing on a particular genetic condition. If a person wishes to avoid passing on a particular genetic condition, they may use genetic testing. One type is prenatal testing, which is carried out on a pregnant person or the embryo they are carrying.
Another type is pre-implantation genetic testing, which can only be used to test for conditions where one specific gene is the known cause. To use this, prospective parents create a number of embryos using in-vitro fertilisation (IVF). Pre-implantation genetic testing then allows the selection of embryos that do not carry the specific gene variant that causes the inherited condition. Those embryos are then transferred to the parent’s womb.
Genome editing for ‘enhancement’
Could genome editing be used to ‘enhance’ the human body, by editing in traits that are considered ‘desirable’? Even if it were legal (which it isn’t in the UK and many other countries), heritable genome editing is not currently capable of allowing people to ‘design’ babies, and it isn’t likely to be in the near future. Many human traits are shaped by a complex combination of factors, which may include several or dozens of genes, as well as the impacts of nutrition, environment, lifestyle and life experiences.
Roll of the dice
At times, life can feel like a game of chance. From the DNA we were born with, to all the twists and turns along the way that will affect who we are and how we live, so much is beyond our control. Genome editing offers us the possibility of changing the hand that nature - and other complex forces - may have dealt us. How might we use it to change ourselves and the world around us?
Roll up! Roll up!
Genome editing can be used in many different ways - and new applications are being developed all the time. Play the game to find out more and have your say:
- Roll the dice to randomly select one of six topic cards...
- Match the picture on the dice with one of the six topic cards. Take that card to explore the topic further…
- Grab a ping pong ball which matches the colour of your topic card. Answer the question on your card by deciding where you would draw the line - and take a look at how other visitors have responded.
Should genome editing be used to help solve global health issues?
Poor diets - lacking in protein, energy, iron, zinc, vitamin A and iodine - cause the deaths of around 30,000 people each day globally.
Rice is an important food eaten by more than 3.5 billion people around the world. Scientists have been trying to improve its nutrition for years through complex and time-consuming analysis and selective breeding programmes.
In the late 1990s, scientists used a forerunner of genome editing to create golden rice, rich in a plant pigment called beta-carotene, which the body converts to vitamin A. Lack of vitamin A is estimated to kill more than 670,000 children under five every year and causes an eye problem called night blindness. Due to strict regulations around the development and testing of genetically altered foods, it wasn’t until 2018 that the US, Australia, Canada and New Zealand approved golden rice for human consumption.
Genome editing offers a more efficient and cost-effective way of making crops that are resistant to disease and changes in climate, and provide better nutrition.
- Supporters of genome editing crops argue that if plants such as golden rice can be developed, it is unethical to deny millions of people a cure for diseases such as night blindness.
- Golden rice only focuses on one element of a poor diet. Programmes that improve access to vitamin-rich fruit and vegetables can be a more effective solution.
- In the UK, a recent trial was conducted using genome edited Camelina oilseed plants. These have been edited to produce omega 3 oil, potentially removing the need to feed small fish (the current source of omega 3) to farmed salmon. This could have animal welfare and environmental benefits.
- Some people argue that trying to solve global health problems through genome editing crops or fish isn’t the answer. Instead, we need to move to more sustainable, varied and ethical farming and fishing models that use fewer resources that are more fairly distributed.
- According to the UN, the global population is expected to reach 10 billion by 2050. Genome edited food could help reduce the use of water, fertiliser and pesticides, and cut down food waste, while improving the amount of crops produced, diets and health.
- People who oppose genome edited foods worry that these crops could bring unintended and unknown long-term consequences to wildlife, ecosystems and human health.
Should genome editing be used to help solve environmental crises?
Climate change poses a threat to human and planetary life. As the Earth continues to warm, floods, fires and megastorms are becoming more common. Meanwhile, melting ice caps and glaciers will cause sea levels to rise, soaking large areas of fertile land with saltwater, eroding coastlines and flooding cities.
Farming plays a big role in climate change; farm animals produce around 14.5% of all greenhouse gas emissions. This is mostly from the methane in cows’ burps. Methane is almost 30 times more powerful a greenhouse gas than carbon dioxide.
Scientists have found that there are microbes (tiny living things) in cows’ guts that produce this methane - and there’s a connection between these microbes and cows’ genomes. Genome editing could be used to identify and treat the animals most likely to produce methane and reduce greenhouse gas emissions.
- For generations, cows have been selectively bred to produce the animals we’re familiar with today that provide us with beef or milk. Genome editing to create cows that produce less greenhouse gas is simply a next step.
- There is an argument that keeping fewer cows in better conditions and reducing or giving up beef and milk are more ethical and sustainable solutions.
- There will always be people who want to eat meat and dairy products. Editing the genomes of cows, pigs, sheep and chickens to grow bigger, faster, and to provide more food for humans while reducing the impact on the environment should be a priority.
- Huge amounts of crops grown are used to feed animals. Animals are inefficient in turning these crops into proteins. Some people think that it would be more efficient to cut out eating meat altogether, freeing up farmland for other purposes.
- Genome editing could be used to improve the efficiency of how animals convert crops into protein. It could also be used to produce animals that are resistant to deadly viral diseases such as African swine fever or bird flu, which could become more common in a changing climate.
Sickle cell disease
Should genome editing be used to cure inherited diseases?
There are many diseases that can be inherited, such as sickle cell disease. Sickle cell disease means that red blood cells, which are usually round and flexible, are crescent or “sickle” shaped. These can clump together and clog blood vessels, which can cause severe pain, anaemia, stroke, organ failure and early death. Sickle cell disease can affect anyone, although it mainly affects people of African and Caribbean heritage.
Scientists have developed a number of ways to treat the disease using genome editing tools. In 2019, a patient in the US with sickle cell disease was successfully treated using genome editing. Firstly, special stem cells that can turn into different types of blood cells were removed from her bone marrow. The DNA of these stem cells was edited, so that they produced new, healthy red blood cells once they were put back into her bone marrow, replacing the “sickle” shaped cells.
Because this treatment is somatic, it only affects the individual rather than altering the DNA that is passed on to the next generation. That means the patient’s children might still develop sickle cell disease, if they inherit the disease-causing gene variant from both parents.
- Somatic genome editing could be used to treat the estimated 15,000 people in the UK currently living with sickle cell disease. It could provide a one time treatment for sickle cell instead of a lifetime of medical interventions. This could hugely improve quality of life for those patients.
- The treatment is currently very expensive which means these treatments may not be accessible to the 200,000 to 300,000 children born with sickle cell disease in Africa each year.
- Sickle cell disease disproportionately impacts people of African and Caribbean heritage. Because of the legacies of slavery and the abuse of African Americans in medical research and experiments, as well as the ongoing racism and health inequalities that black people and people of colour face, many may be wary of potential new treatments like genome editing.
- Over 100 research projects and clinical trials are showing encouraging signs that genome editing could be used in the future to prevent or treat a wide variety of inherited diseases, including some eye diseases, HIV, haemophilia B (a blood clotting disease), cystic fibrosis (a condition that causes sticky mucus to build up in the lungs and digestive system) and some cancers.
Should genome editing enhance our minds and bodies?
NASA, the US space agency, is currently working towards a future crewed mission to Mars. However, humans are not well suited to spending a long time in space. Exposure to radiation, the lack of gravity and years spent in an enclosed spacecraft would all have negative effects on the health of astronauts on a long space flight.
Scientists have identified more than 40 genes that could potentially be edited in the future to make humans resistant to radiation damage, grow harder and denser bones, be able to exist on less oxygen, be less anxious - and even smell less in confined spaces!
- Some people would argue that editing the human genome to produce people equipped for space travel is unethical. Other alternatives exist, such as robots and even artificial intelligence, which are much better suited to exploring new planets.
- It is unethical to edit future generations to be better suited to particular jobs, or to have other so-called ‘advantages’, as they have no control over that decision. Would you volunteer your own relatives?
- These futuristic enhancements may seem extreme now, but many of the ways that we try to improve our minds and bodies - from education and exercise to cosmetic surgery, or even access to new experiences and technology - would have seemed unbelievable to past generations.
- Closer to home, genome editing could be used to enhance our bodies to adapt to climate change - for example, needing less water or being able to withstand hotter temperatures.
- Genetic enhancements would be even more expensive than current lifestyle enhancements. This would increase inequality between those who could afford enhancement and those who couldn’t, creating a sense of ‘genetic advantage’ for a minority of people.
Should genome editing be used on entire species to get rid of infectious disease?
Malaria is a disease caused by a parasite carried by infected mosquitoes, which pass on the disease through their bites. The parasite multiplies rapidly inside red blood cells before bursting out and infecting more blood cells.
According to the World Health Organisation, a child dies of malaria every two minutes and each year there are more than 200 million new cases of the disease. In 2020, an estimated 67% of all malaria deaths were of children under five.
Scientists at the Francis Crick Institute have been using the CRISPR genome editing tool to understand how the malaria parasite infects red blood cells. By editing the parasite’s DNA to “switch off” an important section, they can see what happens when the parasite tries to multiply by breaking out of a red blood cell to infect others.
- Editing the genome of the malaria parasite in the lab to advance our understanding is part of basic scientific research. The experiment carries no risk of altering mosquitoes or the malaria parasite in the wild, and the results could save millions of lives by helping to develop new drugs specifically designed to target malaria.
- Beyond the lab, researchers are exploring using “gene drives” to reduce or even eliminate certain species of mosquitoes that carry the worst types of malaria. This uses special genome editing methods which make all the descendants of an edited male mosquito infertile. However, there are concerns that gene drives could have unintended negative effects on the ecosystems where these mosquitoes live.
- There are organisations in Africa and other Global South regions that voice concern that they may become test subjects for scientists from richer countries in the Global North. They see this as another kind of medical colonialism, where genome editing tools and their results benefit interests in the Global North, but may bring unintended consequences in communities where gene drives are carried out.
Should we use heritable human genome editing for challenges that could be solved in other ways?
Heritable genome edits which are carried out on egg and sperm cells or early embryos, and which can be passed down from parent to child, present the biggest ethical and safety concerns. In the UK it is only permitted in lab research to improve understanding of human biology and development, and is very strictly controlled. But using genome editing to alter the DNA of embryos for implantation in a person’s womb is currently illegal in the UK and prohibited in many other countries. However, it is known to have happened once.
In 2018, Chinese scientist Dr He Jiankui revealed that his team had edited the genome of twin girls to try to prevent HIV transmission from their father, who carries the virus. The twins, and a third baby girl born soon after, are the first human subjects of heritable genome editing, meaning that the changes to their DNA could be passed down.
Dr He was sent to prison for his unethical practice, and the experiment was widely condemned by the scientific community - particularly as there are other ways to avoid HIV transmission (and very effective treatments).
However, Russian scientist Denis Rebrikov is one exception. In 2019 he developed a technique to edit a gene variant linked to deafness, and has said openly that he plans to implant genome-edited embryos for a number of D/deaf couples.
- Some people see heritable genome editing (if it can be shown to be safe, which it isn’t at present) as one way to avoid passing on genetic conditions they view as severe.
- Many Deaf and disabled people are concerned that genetic conditions and difference are often seen as something to be avoided or ‘cured’. Heritable genome editing technology could be exploited to reinforce these beliefs, and be used in the future to erase aspects of disabled and Deaf people’s identities, when instead we should be challenging societal barriers to disability and negative attitudes to difference.
- In response to the He Jiankui case, the Chinese government reformed its laws and civil codes to create stricter regulations and governance of genome editing research.
- Regulating human genome editing globally is very challenging, and depends on a wide variety of processes, including control of research via funding decisions and peer pressure in the scientific community.
- Heritable genome editing would mean long-term monitoring of future generations of DNA-edited individuals in case medical problems appear down the line. Who would pick up the cost of dealing with those problems?
Make your mark
Should genome editing be used in the fight against climate change? Should parents be able to alter the genomes of children yet to be born? Should genome editing be used to create new or ‘’improved” human abilities? How should these questions be decided?
From use in scientific research to combating environmental crises, from treating diseases to human enhancement, we want to hear your views about the ethics of genome editing. More people should have a chance to feed into how these technologies are used in the future, and this is a space for you to be part of these conversations.
So what do you think?
We invite you to write, draw, or record your reflections and questions on the ethics of genome editing, which will be shared with Crick scientists and staff. Jot them down on a tag, or record them and add them to the growing web. Post them to @TheCrick on Twitter or @thefranciscrickinstitute on Instagram with the hashtag #CutAndPaste.
Look out for answers to some of your questions from Crick scientists at crick.ac.uk/CutAndPasteAnswers. Some of your comments may also be explored at Crick public events that accompany the exhibition. For details, see crick.ac.uk/CutAndPasteEvents.
Please note that recorded comments and questions may be shared (in written form only) on the Crick website and social media. Written comments may also be shared online.
- If you could change one thing about yourself, what would it be?
- Is there any feature you would rather not pass on? Why?
- Genome editing has the power to shape the future. Whose vision of the future should it be?
- Which human characteristics are 'desirable'? Why?
- Somatic genome editing of a person's body cells, where the edits are not passed onto future generations, could be used to treat people living with certain genetic conditions. How do you feel about this?
- Heritable genome editing of embryos, or of cells that give rise to sperm or eggs, might alter characteristics that could be passed onto future generations. How do you feel about this?
- Genome editing could be used to avoid or treat 'severe' conditions. Who gets to decide which conditions are 'severe' and should be treated?
- Genome editing could enable parents to alter the DNA of embryos, so that their future children could avoid a particular genetic condition. What do you think about this?
- Should genome editing be used to create human 'enhancements'? How can 'enhancement' be defined?
- If genome editing in plants or animals could help to reduce hunder or malnutrition, would you support it?
The Francis Crick Institute would like to acknowledge the contribution made by the individuals who have dedicated their time and expertise to the exhibition. In particular, we would like to thank:
Crick scientists and advisors to the exhibition
Robin Lovell-Badge, Güneş Taylor
Design, build, audio visual
The Liminal Space
Steering committee members
Cristina Vidal Franco
Sincere thanks also to the following individuals and organisations who have contributed to the exhibition:
Georgia Monk, Wellcome Collection
Ollie Isaac, Wellcome Collection
Goss Consultancy Ltd
Easy Read UK
Guide to exhibition language
Gene - A gene is the basic physical ‘unit’ of inheritance which is passed from parents to their biological children. The genes contain the information that shape a person’s physical and biological traits. Genes are contained within DNA.
DNA - Sequences of chemicals that are stored in thread-like strands called chromosomes which are found in the nucleus, the ‘control centre’ of the cell. Genes are written into DNA, which is inherited in every cell in the body.
Genome - The entire set of genetic instructions that are found in a cell. A genome is shared between all members of a species, but each individual has their own unique genome.
Genetic condition - A condition caused by a gene variant that is passed down from parent to child.
Pre-implantation genetic screening - A technique used to identify genetic variants in embryos that have been created through in vitro fertilisation (IVF).
Pre-natal testing - Tests that are performed on an embryo or a fetus, to identify whether (or the likelihood that) an embryo or fetus has a genetic variant.
Genome editing - A group of technologies that gives scientists the ability to alter an organism's DNA.
Heritable genome edits - A form of genome editing, not currently legal in the UK and many other countries, that is carried out on the sperm or egg cells, or an early embryo, the effect of which is passed onto future generations.
Somatic genome edits - A form of genome editing that is carried out on an individual’s body, the effect of which is not passed onto future generations.
Enhancement - In this exhibition, this refers to the concept of human ‘enhancement’ to achieve ‘improved’ physical or mental capabilities by means of genetic modification.
Genetically altered or modified organism - An organism, such as a plant, animal or human, whose genome has been altered by genome editing technologies.
Gene drive - A form of genome editing which provides a mechanism by which a desired genetic variant can be spread through a population (eg, in a species of mosquitoes)