Embryo Project Encyclopedia

In 1962 researcher John Bertrand Gurdon at the University of Oxford in Oxford, England, conducted a series of experiments on the developmental capacity of nuclei taken from intestinal epithelium cells of feeding tadpoles. In the experiments, Gurdon conducted nuclear transplantation, or cloning, of differentiated cells, or cells that have already specialized to become one cell type or another, in tadpoles. Gurdon's experiment showed that differentiated adult cells could be induced to an undifferentiated state, where they could once again become multiple cell types. Gurdon's experiment disproved the theory that differentiated cells could not be undifferentiated or dedifferentiated into a new type of differentiated cell. Gurdon's experiment demonstrated nuclear transplantation, also called cloning, using differentiated cells.

In the early 2000s, Sabata Martino and a team of researchers in Italy and Germany showed that they could reduce the symptoms of Tay-Sachs in afflicted mice by injecting them with a virus that infected their cells with a gene they lacked. Tay-Sachs disease is a fatal degenerative disorder that occurs in infants and causes rapid motor and mental impairment, leading to death at the ages of three to five. In gene therapy, researchers insert normal genes into cells that have missing or defective genes in order to correct genetic disorders. The team created a virus that coded for a specific gene missing in mice with Tay-Sachs. That missing gene is called hexosaminidase subunit alpha (HEXA). Martino and the team injected the virus into the brains of mice with Tay-Sachs in attempt to restore Hexa enzymatic function in the brain and spinal cord (central nervous system).

The goal of this research project was to examine how different messaging techniques, and especially expressions of emotionality surrounding the loss and recovery of biodiversity, can differently influence public attitudes about conservation and the environment. This question was explored using the case of de-extinction, an emerging and controversial conservation technology. De-extinction claims to “resurrect” extinct species, challenging widely held notions of extinction as permanent. Yet seeing extinction as reversible may shift how people feel about biodiversity loss and our moral responsibility to stop it.

In the second half of the
twentieth century, scientists learned how to clone organisms in some
species of mammals. Scientists have applied somatic cell nuclear transfer to clone human and
mammalian embryos as a means to produce stem cells for laboratory
and medical use. Somatic cell nuclear transfer (SCNT) is a technology applied in cloning, stem cell
research and regenerative medicine. Somatic cells are cells that
have gone through the differentiation process and are not germ
cells. Somatic cells donate their nuclei, which scientists
transplant into eggs after removing their nucleuses (enucleated eggs).
Therefore, in SCNT, scientists replace the nucleus in an egg cell
with the nucleus from a somatic cell.

The Boys from Brazil is a science fiction film based on the novel of the same name by Ira Levin about an underground neo-Nazi society in South America trying to clone Adolf Hitler, the dictator of Nazi Germany during World War II, to restore the Nazi movement. The film was directed by Franklin Schaffner and released in 1978 by 20th Century Fox in Los Angeles, California. The Boys from Brazil is a film that was one of the first films to depict cloning, and to discuss the ethical implications of genetic engineering, cloning, and eugenics.

The Case against Perfection: Ethics in the Age of Genetic Engineering, hereafter referred to as The Case against Perfection, written by Michael J. Sandel, builds on a short essay featured in The Atlantic Monthly magazine in 2004. Three years later, Sandel transformed his article into a book, keeping the same title but expanding upon his personal critique of genetic engineering. The purpose of Sandel's book is to articulate the sources of what he considers to be widespread public unease related to genetic engineering that changes the course of natural development.

In 2018, He Jiankui uploaded a series of videos to a YouTube channel titled “The He Lab” that detailed one of the first instances of a successful human birth after genome editing had been performed on an embryo using CRISPR-cas9. CRISPR-cas9 is a genome editing tool derived from bacteria that can be used to cut out and replace specific sequences of DNA. He genetically modified embryos at his lab in Shenzhen, China, to make them immune to contracting HIV through indirect perinatal transmission from their father, who was infected with the virus. HIV is a virus that attacks the immune cells of its host and weakens their ability to fight off diseases. At the time of He’s experiment, various treatments already existed at that could prevent the fetuses from contracting HIV without the need for gene surgery. Nonetheless, He’s experiment led to one of the first successful births of fetuses resulting from genetically modified embryos. He kept his experiment secret until he uploaded the videos announcing the birth of the fetuses, born as two twin girls. The experiment discussed in the videos was successful, but many scientists criticized the experiment due to ethical concerns with the way He conducted it.

In 2003, Carmina Gisbert and her research team produced a tobacco plant that could remove lead from soil. To do so, they inserted a gene from wheat plants that produces phytochelatin synthase into a shrub tobacco plant (Nicotiana glauca) to increase N. glauca's absorption and tolerance of toxic metals, particularly lead and cadmium. Gisbert and her team aimed to genetically modify a plant so that it could be used for phytoremediation- using plants to remove toxic substances from the soil. Scientists have identified phytoremediation as an effective and efficient process to improve human health and reproductive health in contaminated areas. Metals like mercury and lead can cause birth defects during human development like cognitive impairment, cerebral palsy, deafness, tremors, and blindness.

In 2015, Revive & Restore launched the Woolly Mammoth Revival Project with a goal of engineering a creature with genes from the woolly mammoth and introducing it back into the tundra to combat climate change. Revive & Restore is a nonprofit in California that uses genome editing technologies to enhance conservation efforts in sometimes controversial ways. In order to de-extinct the woolly mammoth, researchers theorize that they can manipulate the genome of the Asian elephant, which is the mammoth’s closest living evolutionary relative, to make it resemble the genome of the extinct woolly mammoth. While their goal is to create a new elephant-mammoth hybrid species, or a mammophant, that looks and functions like the extinct woolly mammoth, critics have suggested researchers involved in the project have misled and exaggerated the process. As of 2021, researchers have not yet succeeded in their efforts to de-extinct the woolly mammoth, but have expressed that it may become a reality within a decade.

In the 1990s, researchers working at the Roslin Institute in Edinburgh, Scotland, performed cloning experiments in collaboration with PPL Therapeutics in Roslin, Scotland, on human coagulation factor IX, a protein. The team of scientists used the methods identified during the Dolly experiments to produce transgenic livestock capable of producing milk containing human blood clotting factor IX, which helps to treat a type of hemophilia. By using a cell's resting state, called quiescence, or G0, and transferring modified nuclear material from one cell to an egg cell that had had its nuclear material removed, the researchers developed a method to produce genetically modified mammals, including humans. Angelika E. Schnieke, Alexander J. Kind, William A. Ritchie, Karen Mycock, Angela R. Scott, Marjorie Ritchie, Ian Wilmut, Alan Colman, and Keith H. S. Campbell published the results of their experiments as Human Factor IX Transgenic Sheep Produced by Transfer of Nuclei from Transfected Fetal Fibroblasts (hereafter called Human Factor IX). The article details the methods that produced the cloned sheep named Polly, as well as other cloned and genetically altered sheep.