Somatic cell nuclear transfer (SCNT) involves transferring the nucleus of a donor somatic cell into an egg cell whose nucleus has been removed. In 1997, scientists at the Roslin Institute succeeded in cloning Dolly the sheep using SCNT after previous failed attempts. Dolly was born after the nucleus of a mammary cell was fused with an enucleated sheep egg cell, which was then implanted into a surrogate ewe. Dolly lived for six years and gave birth to six lambs of her own, but had health issues like premature aging. While SCNT offers potential benefits in agriculture, medicine and conservation, it also faces challenges like low cloning efficiency and health problems in cloned animals.

1. SOMATIC CELL
CLONING
- PRIYA BHATT
201643
MSc. BIOTECHNOLOGY

2. SOMATIC DONOR
ENUCLEATED EGG DONOR
CELL GROWTH IN TISSUE CULTURE
IMPLANTATION TO SURROGATE MOTHER

3. HISTORY OF THE SOMATIC CLONED ANIMAL
In 1952, Briggs and King developed a frog of species Rana pipiens
In 1975, Derek Bromhall in Oxford, UK carried out the same
experiment on rabbit but it died at morula stage.
Steen Willadsen at the Institute of Animal Physiology in Babraham
Institute,UK, was the first to clone a sheep embryo in 1984 but
was a fail.
In 1996, Keith Campbell, Jim McWhir, William Ritchie, and Ian
Wilmut at the Roslin Institute in Edinburgh, failed to clone the
sheep
In 1997, the Rosalin Institute however succeeded.
SOURCE : Bartlett, Zane, "Somatic Cell Nuclear
Transfer in Mammals (1938-2013)". Embryo
Project Encyclopedia (2014-11-04). ISSN: 1940-
5030

4. Mammary cells removed from a 6 years old Ewe
Cells placed in culture dish and were starved to death
Cells were then fused with the enucleated egg cells
Egg was then implanted into Ewe
After 148 days, a healthy lamb was born- Dolly.
DOLLY - AFTER 277 ATTEMPTS
SOURCE : Bartlett, Zane, "Somatic Cell Nuclear
Transfer in Mammals (1938-2013)". Embryo Project
Encyclopedia (2014-11-04). ISSN: 1940-5030

5. ENUCLEATION

6. INSERTING
NUCLEUS

7. Birth - 5th July 1997
First wave of concern :
Telomeres shorter than normal
Allowed to breed noemally
Had 6 lambs
In 2001, it suffered from Arthritis
Death - 14th Feb, 2003
LIFE CYCLE OF DOLLY
SOURCE : www.google.com, slodeshare- Genetic
manipulations in animals

8. The Roslin Technique Honolulu Technique
The somatic cells are first grown in
culture deprived of nutrients and
then its nucleus is fused with egg
by heat and shock treatment.
- DOLLY
Developed by Dr. Teruhiko
Wakayama at the University of
Hawaii. Here the direct nucleus
extracted from the somatic cell is
made to fuse to the egg using
chemical treatment.
- CUMULINA MOUSE
2
MAJOR
TECHNIQUES
USED
IN
SOMATIC
CLONING
SOURCE : www.google.com, slodeshare- Genetic
manipulations in animals

9. LESSONS LEARNT FROM SOMATIC
CELL NUCLEAR TRANSFER

10. The first defect in clones is genome instability
Miscarriage and fetal mortality rates are high
Bovine clones - susceptible to obesity
Pigs - Underweight, underdeveloped placentas
MICE - Abnormal epigenetic modifications
Cell cycle stage incompatibility between donor
somatic cell nuclei and the cytroplasm causing
aneuploidy.
Ethical issues
Source : Chantel Gouveia, Carin Huyser, Dieter Egli and Michael S. Pepper,
Lessons Learned from Somatic Cell Nuclear Transfer, Int. J. Mol. Sci. 2020, 21,
2314; doi:10.3390/ijms21072314

11. POSITIVE
TRAITS
Agriculture
allows genetic conservation
of local breeds with unique
tolerance for regional
diseases or local climates.
SCNT also allows spread of
disease resistance faster
than traditional techniques
Inexpensive
results are faster and more
predictable than in previous
reproductive techniques like
artificial insemination
Medical
Therapeutics
Replacement tissues &
organs;
Prevention of immunological
tissue rejection
Gene therapy
ability to prevent, treat and
overcome: Aging, Disease,
Cancers, Myocardial
infractions and Genetic
disorders

12. www.google.com, slodeshare-
Genetic manipulations in animals
REFERENCES
Bartlett, Zane, "Somatic Cell Nuclear Transfer in
Mammals (1938-2013)". Embryo Project
Encyclopedia (2014-11-04). ISSN: 1940-5030
Source : Chantel Gouveia, Carin Huyser, Dieter Egli
and Michael S. Pepper, Lessons Learned from
Somatic Cell Nuclear Transfer, Int. J. Mol. Sci. 2020,
21, 2314; doi:10.3390/ijms21072314

13. THANK YOU !!