How Dolly the sheep was cloned
Overview of somatic cell nuclear transfer (SCNT). In 1996 the first clone of an adult mammal, a female sheep named Dolly, was born. Dolly was created using SCNT, a process that later became a cornerstone of stem cell research.
Encyclopædia Britannica, Inc.
-
Encyclopædia Britannica, Inc.Is the message behind urban foraging: “Don't eat that”?Media Editors: Meg Matthias , Kira Helm
-
Encyclopædia Britannica, Inc.Resist the urge to grab a cotton swab.
-
© University of Melbourne, Victoria, Australia (A Britannica Publishing Partner)See a 3-D simulation of the motion of the human rhinovirus, the virus that causes the common cold. The simulation was produced with the aid of the IBM Blue Gene/Q supercomputer.
-
Encyclopædia Britannica, Inc.Overview of the potential use of cloning in conservation of species.
-
AbbVie (A Britannica Publishing Partner)A scientist describing how her childhood curiosity spurred her career choice.
-
© Open University (A Britannica Publishing Partner)Learn about the future of quantum technology.
-
Encyclopædia Britannica, Inc.In 1996 the first clone of an adult mammal, a female sheep named Dolly, was born. Dolly was created using somatic cell nuclear transfer (SCNT), a process that later became a cornerstone of stem cell research.
Transcript
In 1996 the first clone of an adult mammal, a female sheep named Dolly, was born. To create Dolly, scientists used somatic cell nuclear transfer, or SCNT, a revolutionizing technique that now is a cornerstone of stem cell research.
In SCNT scientists begin by removing the nucleus from a somatic, or body, cell of a donor mammal.
They then collect an egg cell from a donor of the same species.
The egg cell nucleus is removed and replaced with the nucleus of the somatic cell.
Once inside the egg, the somatic nucleus is reprogrammed by cytoplasmic factors in the egg, returning it to an undifferentiated, embryonic stage.
The egg may then be implanted into the uterus of a surrogate mother to produce a cloned animal through a process known as reproductive cloning.
Alternatively, it may remain in the laboratory, to be used in studies of therapeutic cloning. In therapeutic cloning, the fertilized, fused egg cell is allowed to develop to the blastocyst stage.
From the blastocyst's inner cell mass, scientists produce a culture of embryonic stem cells (ESCs).
Through the process of differentiation, ESCs develop into any one of the many different types of mature body cells that make up an organism. Because ESCs have the capacity to differentiate, they are a promising means for potentially replacing defective or diseased cells in human patients.
They then collect an egg cell from a donor of the same species.
The egg cell nucleus is removed and replaced with the nucleus of the somatic cell.
Once inside the egg, the somatic nucleus is reprogrammed by cytoplasmic factors in the egg, returning it to an undifferentiated, embryonic stage.
The egg may then be implanted into the uterus of a surrogate mother to produce a cloned animal through a process known as reproductive cloning.
Alternatively, it may remain in the laboratory, to be used in studies of therapeutic cloning. In therapeutic cloning, the fertilized, fused egg cell is allowed to develop to the blastocyst stage.
From the blastocyst's inner cell mass, scientists produce a culture of embryonic stem cells (ESCs).
Through the process of differentiation, ESCs develop into any one of the many different types of mature body cells that make up an organism. Because ESCs have the capacity to differentiate, they are a promising means for potentially replacing defective or diseased cells in human patients.