GROUP FOUR(CLONING)

PRESENTED BY: MUNZ

CLONING

What is cloning?

- According to the National Human Genome Research Institute:

The term cloning describes a number of different processes that can be used to produce genetically identical copies of a biological entity.

THE HISTORY OF CLONING

1885 - First-ever demonstration of artificial embryo twinning

• Sea urchin Hans Adolf Edward Dreisch

• The sea urchin is a relatively simple organism that is useful for studying development. Dreisch showed that by merely shaking two-celled sea urchin embryos, it was possible to separate the cells. Once separated, each cell grew into a complete sea urchin.

• This experiment showed that each cell in the early embryo has its own complete set of genetic instructions and can grow into a full organism.

1902 - ARTIFICIAL EMBRYO TWINNING IN A VERTEBRATE

• Salamander Hans Spemann

• Spemann’s first challenge was to figure out how to split the two cells of an embryo much stickier than sea urchin cells. Spemann fashioned a tiny noose from a strand of baby hair and tightened it between two cells of a salamander embryo until they separated. Each cell grew into an adult salamander. Spemann also tried to divide more advanced salamander embryos using this method, but he found that cells from these embryos weren’t as successful at developing into adult salamanders.

• This experiment showed that embryos from a more-complex animal can also be “twinned” to form multiple identical organisms—but only up to a certain stage in development.

1958 - NUCLEAR TRANSFER FROM A DIFFERENTIATED CELL

• Frog John Gurdon

• Gurdon transplanted the nucleus of a tadpole intestinal cell into an enucleated frog egg. In this way, he created tadpoles that were genetically identical to the one from which the intestinal cell was taken.

• This experiment showed that, despite previous failures, nuclei from somatic cells in a fully developed animal could be used for cloning. Importantly, it suggested that cells retain all of their genetic material even as they divide and differentiate (although some wondered if the donor DNA came from a stem cell, which can differentiate into multiple types of cells).

1975 - FIRST MAMMALIAN EMBRYO CREATED BY NUCLEAR TRANSFER

• Rabbit J. Derek Bromhall

• Mammalian egg cells are much smaller than those of frogs or salamanders, so they are harder to manipulate. Using a glass pipette as a tiny straw, Bromhall transferred the nucleus from a rabbit embryo cell into an enucleated rabbit egg cell. He considered the procedure a success when a morula, or advanced embryo, developed after a couple of days.

• This experiment showed that mammalian embryos could be created by nuclear transfer. To show that the embryos could continue developing, Bromhall would have had to place them into a mother rabbit's womb. He never did this experiment.

1996 - DOLLY: FIRST MAMMAL CREATED BY SOMATIC CELL NUCLEAR TRANSFER

• Sheep Ian Wilmut and Keith Campbell

• In this landmark experiment, Wilmut and Campbell created a lamb by transferring the nucleus from an adult sheep's udder cell into an enucleated egg. Never before had a mammal been cloned from an adult somatic cell. What was the big deal?

• Every cell’s nucleus contains a complete set of genetic information. However, while embryonic cells are ready to activate any gene, differentiated adult cells have shut down the genes that they don't need for their specific functions. When an adult cell nucleus is used as a donor, its genetic information must be reset to an embryonic state. Often the resetting process is incomplete, and the embryos fail to develop.

• Of 277 attempts, only one produced an embryo that was carried to term in a surrogate mother. This famous lamb, named Dolly, brought cloning into the limelight. Her arrival started conversations about the implications of cloning, bringing controversies over human cloning and stem cell research into the public eye.

2001 - ENDANGERED ANIMALS CLONED BY SOMATIC CELL NUCLEAR TRANSFER

• Gaur and Mouflon Multiple groups

• As the list of successfully cloned animals grew, scientists began to explore cloning as a way to create animals belonging to endangered or extinct species. A challenge to cloning endangered and extinct species is finding closely related animals to serve as egg donors and surrogates. The gaur and mouflon were chosen in part because they are close relatives of domestic cattle and sheep, respectively.

• In 2009, using goats as egg donors and surrogates, another group of researchers cloned the first extinct animal, a Spanish mountain goat called the bucardo. Sadly, the one kid that survived gestation died soon after birth due to a lung defect.

2013 - HUMAN EMBRYONIC STEM CELLS CREATED BY SOMATIC CELL NUCLEAR TRANSFER

• Human Shoukhrat Mitalipov and colleagues

• Overcoming decades of technical challenges, Mitalipov and colleagues were the first to use somatic cell nuclear transfer to create a human embryo that could be used as a source of embryonic stem cells. The resulting stem cell lines were specific to the patient they came from, a baby with a rare genetic disorder.

• In this experiment, researchers took a skin cell from the patient and fused it with a donated egg cell. Key to the success of the experiment were modifications to the culture liquid in which the procedure was done and to the series of electrical pulses used to stimulate the egg to begin dividing.

• Following the cloning controversy of 2004–2005, in which South Korean scientists falsely claimed to have used somatic cell nuclear transfer to create embryonic stem cell lines, the scientific community demanded much stronger evidence that the procedure had actually been successful.

NATURAL CLONING

• Cloning also happens outside the lab too. Its also a natural process, some bacteria, plants and even some animals will also naturally clone because of their natural reproductive cycle.

• The term clone comes from the Greek word kládos meaning twig, because they used to make new trees by using cuttings, you would graft a cutting, instead of growing from a seed. I would be faster.

CONTD

• Single celled organism and some plants would naturally clone as well, through asexual reproduction. Asexual reproduction is done with only one set of cells, it makes an identical offspring to the parent cell. It is essentially like a clone.

• Three basic ways asexual reproduction causes cloning:

CONTD

i. Binary Fusion - A parent cell splits into two cells, living two genetically identical daughter cells, which are natural clones. E.g. bacteria, amoeba.

ii. Clonal Fragmentation - Parent would break into multiple fragments or pieces and develop into organism with the same genetic make up e.g. plants, starfish

iii. Budding – A copy starts growing when its attached to a parent. Once its fully formed it breaks away and forms a whole new organism. E.g. sponges, yeast

CONTD

• Parthenogenesis – Reproduction without fertilisation. It may not be technically cloning(there are genetic changes). So no male is fertilising a female egg. Offspring's are usually female and they are usually clones of their mother. E.g. komodo dragons, bees, wasps, boa constrictor.

• Its essentially a virgin birth.

CONTD

• When you are being made you get half of your mums genes and half of your dads so the egg that is part of parthenogenesis is only the mums genes and they are doubled. So that’s not quite the same as a clone

• Babies are genetically identical to their mother because they only get half of their mothers genes and some scientist don’t feel that means cloning because cloning is 100% identical.

CONTD

• Identical Twins are thought of as some kind of cloning. But its kind of debatable with identical twins.

• Its called monozygotic twins, mono meaning one and zygote referring to fertilized egg cell. These are not clones of parents but sort of clones of each other. The fertilised egg will divide into two eggs and those two eggs almost have identical genetic information.

• They were ones thought to be identical in each every way but ones we got better at reading peoples genes, we found that that is not necessary true.

WHAT I’LL BE COVERING

• What is Cell Cloning?• Cloning unicellular organisms• Somatic-Cell Nuclear Transfer• Ethical Concerns

What is Cell Cloning?

The process of producing a group of cells that are genetically identical (clones) to a single ancestral cell.

CLONING UNICELLULAR ORGANISMS

• In the case of unicellular organisms such as bacteria and yeast, cell cloning is remarkably simple and essentially only requires the inoculation of the appropriate medium.

• However, in the case of cell cultures from multi-cellular organisms, cell cloning is an arduous task as these cells will not readily grow in standard media.

SOMATIC-CELL NUCLEAR TRANSFER(SCNT)

What is SCNT?• In the simplest terms, somatic cell nuclear

transplantation cloning - involves removing the nucleus of an egg and replacing it with the diploid nucleus of a somatic cell.

• Somatic cell is any cell of a living organism other than the reproductive cells.

• Somatic-cell nuclear transfer can also be used to create embryos for research or therapeutic purposes.

• The most likely purpose for this is to produce embryos for use in stem cell research. This process is also called "research cloning" or "therapeutic cloning."

• The goal is not to create cloned human beings (called "reproductive cloning"), but rather to harvest stem cells that can be used to study human development and to potentially treat disease.

FUSION CELL CLONING

• Fusion cell cloning involves replacing the nucleus of an unfertilised egg with the nucleus from a different cell. The replacement nucleus can come from an embryo, but if it comes from an adult cell, it is called adult cell cloning.

• 'Dolly the sheep' was the first mammal to be cloned using adult cell cloning. She was born in the UK in 1996 and died in 2003.

Here’s how she was produced:

• An egg cell was removed from the ovary of an adult female sheep, and its nucleus removed.

• The nucleus from an udder cell of a donor sheep was inserted into the empty egg cell.

• The fused cell then began to develop normally, using genetic information from the donated DNA.

• Before the dividing cells became specialised, the embryo was implanted into the uterus of a foster mother sheep. The result was Dolly, genetically identical to the donor sheep.

ETHICAL CONCERNS

• The announcement of Dolly sparked widespread speculation about a human child being created using somatic cell nuclear transfer. Much of the perceived fear that greeted this announcement centred on the misperception that a child or many children could be produced who would be identical to an already existing person.

CONT.

• This fear is based on the idea of "genetic determinism" -- that genes alone determine all aspects of an individual -- and reflects the belief that a person's genes bear a simple relationship to the physical and psychological traits that compose that individual.

• Although genes play an essential role in the formation of physical and behavioural characteristics, each individual is, in fact, the result of a complex interaction between his or her genes and the environment within which he or she develops. Nonetheless, many of the concerns about cloning have focused on issues related to "playing God," interfering with the natural order of life, and somehow robbing a future individual of the right to a unique identity.

THERAPEUTIC CLONING

Definition

• This is cloning designed as therapy for a disease.

• Production of stem cells for use in replacing or repairing damaged organs or tissue.

• British biologist John Gurdon was the first to successfully clone an animal using SCNT in 1958.

• In this type of cloning, no sperm fertilization is involved nor is there an implantation to the uterus to create a child.

HOW IS IT PERFORMED?

1. A scientist extracts the nucleus that holds the genetic material from an egg.

2. The scientist then takes a somatic cell(any body cell apart from an egg or sperm) from the patient and also extracts the nucleus from this cell.

3. The nucleus from the patient is then inserted into the egg and stimulated to form a cluster of cells(blastocyst).

• This blastocyst has both an outer and inner layer of cells and it is the inner layer, called the inner cell mass that is rich in stem cells.

• The cells in the inner cell mass are isolated and then utilized to create embryonic stem cell lines, which are infused into the patient where they are ideally integrated into the tissues, imparting structure and function as needed.

ILLUSTRATION

BENEFITS

• Cells are pluripotent-meaning they can give rise to all body cells hence potentially treat diseases by replacing damaged and dysfunctional cells.

• The risk of immunological rejection is alleviates the patients’ own genetic material is used.

• It as the potential to reduce wait time for organ transplants as well as concerns with organ transplant therapy.

PROBLEMS

• Egg stability with infused somatic nucleus is poor and can require hundreds of attempts before success is attained.

• It results in embryo destruction after stem cells are extracted, stirring controversy over the morality of the procedure.

• There is a fear that a scientist may attempt to move beyond therapeutic cloning to creation of a human being.

THE ETHICS OF CLONING

• In bioethics, the ethics of cloning refers to a variety of ethical positions regarding the practice and possibilities of cloning, especially human cloning.

• A major objection to cloning (both therapeutic and reproductive) by SCNT is that it is currently an inefficient and unsafe procedure. The evidence from animal clones is that SCNT carries an increased risk of serious genetic malformation, malignancy and reduced longevity.

ETHICS OF CLONING

• Some opponents of reproductive cloning have concerns that technology is not yet developed enough to be safe - for example, the position of the American Association for the Advancement of Science as of 2014, while others emphasize that reproductive cloning could be prone to abuse (leading to the generation of humans from whom organs and tissues would be harvested), and have concerns about how cloned individuals could integrate with families and with society at large

ETHICS OF CLONING

• Religious groups are divided, with some[which?] opposing the technology as usurping God's (in monotheistic traditions) place and, to the extent embryos are used, destroying a human life; others support therapeutic cloning's potential life-saving benefits.

INTERNATIONAL LAWS ON CLONING

Australia

Australia has prohibited human cloning though as of December 2006, a bill legalizing therapeutic cloning and the creation of human embryos for stem cell research passed the House of Representatives. Within certain regulatory limits, and subject to the effect of state legislation, therapeutic cloning is now legal in some parts of Australia.

Canada

Canadian law prohibits the following: cloning humans, cloning stem cells, growing human embryos for research purposes, and buying or selling of embryos, sperm, eggs or other human reproductive material.[42] It also bans making changes to human DNA that would pass from one generation to the next, including use of animal DNA in humans. Surrogate mothers are legally allowed, as is donation of sperm or eggs for reproductive purposes. Human embryos and stem cells are also permitted to be donated for research

COLOMBIA

• Human cloning is prohibited in Article 133 of the Colombian Penal Code

European Union

• The European Convention on Human Rights and Biomedicine prohibits human cloning in one of its additional protocols, but this protocol has been ratified only by Greece, Spain and Portugal. The Charter of Fundamental Rights of the European Union explicitly prohibits reproductive human cloning. The charter is legally binding for the institutions of the European Union under the Treaty of Lisbon and for member states of the Union implementing EU law.

INDIA• India does not have specific law regarding cloning but has guidelines prohibiting whole human cloning

or reproductive cloning. India allows therapeutic cloning and the use of embryonic stem cells for research proposes.

Romania

• Cloning a human is prohibited in Romania.

South Africa

• In terms of section 39A of the Human Tissue Act 65 of 1983, genetic manipulation of gametes or zygotes outside the human body is absolutely prohibited. A zygote is the cell resulting from the fusion of two gametes; thus the fertilized ovum. Section 39A thus prohibits human cloning.

UNITED KINGDOM

• On January 14, 2001 the British government passed The Human Fertilization and Embryology Regulations 2001 to amend the Human Fertilization and Embryology Act 1990 by extending allowable reasons for embryo research to permit research around stem cells and cell nuclear replacement, thus allowing therapeutic cloning.

• However, on November 15, 2001, a pro-life group won a High Court legal challenge, which struck down the regulation and effectively left all forms of cloning unregulated in the UK. Their hope was that Parliament would fill this gap by passing prohibitive legislation. Parliament was quick to pass the Human Reproductive Cloning Act 2001 which explicitly prohibited reproductive cloning. The remaining gap with regard to therapeutic cloning was closed when the appeals courts reversed the previous decision of the High Court.

UNITED NATIONS

• On December 13, 2001, the United Nations General Assembly began elaborating an international convention against the reproductive cloning of humans. A broad coalition of States, including Spain, Italy, the Philippines, the United States, Costa Rica and the Holy See sought to extend the debate to ban all forms of human cloning, noting that, in their view, therapeutic human cloning violates human dignity. Costa Rica proposed the adoption of an international convention to ban all forms of human cloning. Unable to reach a consensus on a binding convention, in March 2005 a non-binding United Nations Declaration on Human Cloning, calling for the ban of all forms of human cloning contrary to human dignity, was adopted

STATE LAWS ON HUMAN CLONING

• There are no federal laws regulating human cloning in the United States, with the exception of laws and policies restricting the federal government from funding human cloning research. However, many states have passed laws on human cloning. Of the states with cloning laws,

• 7 states (Arizona, Arkansas, Michigan, North Dakota, Oklahoma, South Dakota, and Virginia) clearly prohibit both cloning-to-produce-children and cloning-for-biomedical-research;

● 10 states (California, Connecticut, Illinois, Iowa, Maryland, Massachusetts, Missouri, Montana, New Jersey, and Rhode Island) prohibit cloning-to-produce-children while permitting cloning-for-biomedical-research, therefore legally requiring any cloned human embryos to be frozen in perpetuity or destroyed (so-called “clone-and-kill” laws); and

● 1 state (Minnesota) has a statute that would seem to prohibit cloning-for-biomedical-research while not addressing the issue of cloning-to-produce-children.

ADVANTAGES • Organ Replacement

This form of cloning allows scientists to take a small amount of cells from an organ, and harvest an entirely new, functioning one. This is extremely beneficial because of the large amount of people that are on an organ donor waiting list.

• Cloning Help Infertile Couples to Have ChildrenFertility problems could also be potentially eased with the use of genetic cloning. The child could have DNA and qualities from both parents, instead of just one.

• The Benefits of Growing Eminent PersonsVery influential and historical people could possibly be recreated. People such as Martin Luther King Jr. could, theoretically, be brought back to life to educate and help people in today’s world.

DISADVANTAGES• A Degree of Uncertainty

Many of the repercussions and effects of cloning remain unknown. It is a new world of science that is still continually be discovered. There is no real way to tell what the social, mental, and medical consequences may be endured due to cloning.

• New DiseasesCell mutation is a very real possibility with genetic cloning. This may result in new and more aggressive genetic disease to begin within the human race, creating a lot of problems. Many people believe that an event like this will be the demise of civilization.

• Organ Rejection Because of Cell MutationAlthough the technique utilizes the cells of the organ of the recipient, there is still a chance that the cells will mutate. This results to a significant difference on the cell makeup between the replicated and original organ.

FUTURE OF CLONING

• Extinct Animals

• Immortality

• Solution for world hunger

• No more degenerative diseases

CONCLUSION

• Regardless of the present cloning situation, cloning would leads one to a new understanding of biology and medicine.

REFERENCES

• http://learn.genetics.utah.edu/content/cloning/clonezone/

• http://www.genome.gov/

• https://www.genome.gov/10004765

• http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/evolution/reproductionrev5.shtml

• https://en.wikipedia.org/wiki/Cloning#Cell_cloning