By: Amber Heard
Sir John B. Gurdon
Top Medical Researches, Sir John B. Gurdon is a British developmental biologist and geneticist. He was born in 1933 in Dippenhall, England. He is best known for his research on nuclear transplantation and the development of cloned animals, which led to the discovery that the specialization of cells is reversible.
In the late 1950s and early 1960s, Gurdon began experimenting with nuclear transplantation in frog eggs. He took the nucleus from a mature frog cell and inserted it into an egg cell whose own nucleus had been removed. He found that the egg cell could be reprogrammed by the nucleus, and would develop into a healthy tadpole. This was the first demonstration that the differentiation of cells is reversible, and it opened up new possibilities for the understanding of cell specialization and development.
In the 1970s, Gurdon and his team extended their work to other species, including chickens and mice. They were able to successfully clone these animals by transferring the nuclei from mature cells into egg cells. This work was a major breakthrough in the field of developmental biology and genetics, and it laid the foundation for the later development of Dolly the sheep, the first mammal to be cloned from an adult cell.
Gurdon was awarded the Nobel Prize in Physiology or Medicine in 2012, along with Shinya Yamanaka, for his work on the reprogramming of cells. He continues to work in the field of developmental biology and genetics, and his research has had a significant impact on our understanding of cell specialization and development. He is also a Fellow of the Royal Society and a member of the European Molecular Biology Organization.
Nuclear transplantation, also known as somatic cell nuclear transfer (SCNT), is a technique in which the nucleus of a somatic (non-reproductive) cell is transferred into an egg cell from which the nucleus has been removed. The egg cell, now containing the nucleus from a somatic cell, is then induced to begin division and development, resulting in the formation of an organism that is genetically identical to the organism that donated the somatic cell.
This technique was first demonstrated in frogs in the late 1950s by Sir John Gurdon, showing that the differentiation of cells is reversible, and that the genetic information in the nucleus of a somatic cell is capable of directing the development of a complete organism.
Nuclear transplantation has a wide range of potential applications, including the production of genetically identical animals for medical research and the study of genetic diseases, the creation of genetically modified animals for agricultural purposes, and the production of human embryonic stem cells for use in regenerative medicine.
However, the technique also has some ethical concerns, such as the creation of animals for medical research or agricultural use, the potential for the creation of human clones, and the potential for the creation of animals with human characteristics or organs.
In recent years, the field has progressed and other forms of nuclear transfer have been developed such as, Epigenetic reprogramming, which aims to reset the epigenetic marks in a somatic cell nucleus, allowing it to become pluripotent like an embryonic stem cell, leading to more efficient generation of induced pluripotent stem cells (iPSCs) with less genetic variation and more control over the reprogramming process.
A healthy tadpole is a stage in the development of a frog. It is the aquatic larval stage of a frog, which develops from an egg and eventually metamorphoses into an adult frog.
In the process of nuclear transplantation, a nucleus from a mature frog cell is inserted into an egg cell whose own nucleus has been removed. The egg cell is then induced to begin division and development, resulting in the formation of a healthy tadpole.
A healthy tadpole typically has a cylindrical body, a broad head, and a long tail. It has gills for breathing, and a mouth with which to feed on aquatic plants and small aquatic animals. As the tadpole grows and develops, it gradually loses its gills and tail, and develops lungs, legs, and other characteristics of an adult frog.
Tadpoles are important in the life cycle of frogs, as they are the stage in which the frog reproduces, and are also important in the ecosystem as they are an important food source for many aquatic animals.
It is important to note that tadpoles may be exposed to different risk factors that can affect their development and survival. Polluted water, disease, or lack of food are examples of these risks.
Dolly the sheep
Dolly the sheep was the first mammal to be cloned from an adult cell. She was cloned by scientists at the Roslin Institute in Edinburgh, Scotland, using the technique of somatic cell nuclear transfer (SCNT). Dolly was born on July 5, 1996, and lived until February 14, 2003.
The process of cloning Dolly began by taking a somatic cell (a cell from an adult sheep) and removing the nucleus, which contains the sheep’s genetic material. This nucleus was then inserted into an egg cell from another sheep that had had its own nucleus removed. The egg cell was then treated with chemicals and electricity to stimulate cell division, resulting in an embryo. The embryo was then implanted into the uterus of a surrogate mother sheep, who gave birth to Dolly.
Dolly was genetically identical to the sheep that donated the somatic cell, and her birth was a major breakthrough in the field of developmental biology and genetics. It demonstrated that the genetic information in the nucleus of a somatic cell is capable of directing the development of a complete organism, and it opened up new possibilities for the understanding of cell specialization and development.
The cloning of Dolly also raised important ethical questions, such as the potential for the creation of human clones, the production of genetically identical animals for medical research and the study of genetic diseases, and the creation of genetically modified animals for agricultural purposes.
Dolly’s name was inspired by the country singer Dolly Parton and her creation was a remarkable achievement, it was a milestone in the history of science, and it has since been used in many different fields of research.
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine is a prestigious award that is given annually by the Nobel Assembly at Karolinska Institutet in Sweden. It is one of five Nobel Prizes that were established by the 1895 will of Alfred Nobel, a Swedish chemist and inventor.
The Nobel Prize in Physiology or Medicine is awarded to individuals or organizations that have made outstanding contributions to the field of physiology or medicine. It can be awarded for a single discovery or a series of discoveries, and it is given for work that has “conferred the greatest benefit to mankind.”
The award is traditionally presented on December 10, the anniversary of Alfred Nobel’s death. The prize consists of a gold medal, a diploma, and a cash award of 10 million Swedish kronor (about $1.1 million).
Some notable past winners of the Nobel Prize in Physiology or Medicine include:
- Alexander Fleming, who discovered penicillin in 1928
- Roger Guillemin and Andrew Schally, who discovered the hormone-releasing mechanism of the hypothalamus in the 1970s
- Barbara McClintock, who discovered genetic transposition in the 1940s
- James Watson, Francis Crick, and Maurice Wilkins, who discovered the double helix structure of DNA in 1953
- Leland Hartwell, Tim Hunt and Paul Nurse, who discovered the genetic controls of cell division in the 1990s
The Nobel Prize in Physiology or Medicine is considered to be one of the most prestigious awards in the field of medicine and science. The selection process is highly competitive, and the prize is widely considered to be a recognition of the highest achievement in the field of medicine and physiology.