Micromanipulation, methods of micromanipulation and ethical issues

1. MICROMANIPULA
TION
Presented by:
Fizza Mehwish
Presented to:
Sir Yar Muhammad

2. Micromanipulation
Definition
Micromanipulation refers to the
procedure which are performed using
microscopic instruments to manipulate oocytes
(eggs), sperm, and embryos.

3. •Increase chance of fertilization
•Increase pregnancy rate
•Overcome male animal infertility
•Produce more number of clones
•Produce chimera animals
•Appropriate genetic modification

4. The first successful transfer of sheep, pig, and cattle embryos was
reported in the early 1950’s.
Birth of calves and pigs following non surgical, transcervical
embryo transfer were reported in the 1960’s.
Transport of embryos overlong distance was accomplished in the
early 1970’s by placing pig and sheep embryos oviducts of rabbits,
which were used as biological incubators .
The first calf produced from in vitro fertilization was born in 1981.
This was followed by the birth of IVF pigs in 1983. and lambs in
1984.
The birth of the lamb ‘Dolly’, the first animal born following
nuclear transfer or cloning, occurred in 1986.

6. The first micromanipulation technique was partial
zone dissection (PZD), in which the zone
pellucida (ZD) was opened by mechanical force
in order to facilitate sperm access to the oocyte
vestment.
Partial Zone Dissection

7. Continue…
Using PZD resulted in rather high rate of
polyspermy (20-26%) .
PZD was advantageous in Oligozoospermic
patients, but not in cases of Asthenozoospermia,
combined semen problems or immunological
infertility, failed to reach fertilization in case of
severe Teratozoospermia.

8. Subzonal Insemination (SUZI) was the next
procedure where sperm cell were directly
deposited into perivitelline space (PVS).
Subzonal Insemination

9. Continue…
Treatment of the spermatozoa (electroporation or
pentoxyphylline) in order to make them
acrosome-free.
Further help to increase 2PN (2 pro-nuclei /
normally fertilized egg) rate with previous
fertilization failure.
The rate of polyspermy could be significantly
reduced.

10. Natural Fertilization

11. Intracytoplasmic sperm injection is an in vitro
fertilization procedure in which a single sperm
cell is injected directly into the cytoplasm of an
egg.
Intracytoplasmic Sperm Injection

12. Continue…
The typical use of ICSI is extreme male infertility, which
includes:
Oligospermia or extremely low sperm count.
Teratozoospermia or abnormal shape of the sperm.
Asthenozoospermia or poor motility of the sperm.
This technique is more efficient then previous techniques:
•More fertilization rate
•Polyspermy rate reduce to zero.

13. Somatic cell nuclear transfer (SCNT),
or therapeutic cloning, The technique consists of
taking an enucleated oocyte (egg cell) and
implanting a donor nucleus from a somatic (body)
cell.
Somatic cell nuclear transfer

14. Procedure…
 An egg cell is taken and the nucleus and all genetic data is removed
by a micropipette, leaving behind an enucleated egg cell.
A somatic cell, a cell other than the sperm or egg cells, is taken from
the donor.
The nucleus is then separated from the somatic cell by a mild electric
shock.
The donor’s nucleus is then injected into the enucleated cell, causing
the cell to grow as normal. The cells would begin to divide and form
into an embryo.
The nuclear transplanted embryo were cultured in vitro of the
blastocyst stage and transferred into the uterus of a psuedopregnant
female animal.

16. The technique of directly injecting the selected
genes into the eggs acts as a promising technique
for selective alternation in the genetic makeup of
the animal.
Gene transfer is carried out by the process of
Microinjection.
Gene transfer

17. Continue…
The main aim and the practical application of the gene
transfer is that the selective or specific gene of interest
will be injected to the productive large farm animals to
further increase their production strategies and make the
animal to produce valuable products .
The best example to understand the concept is that
growth hormone gene insertion under the control of
promoter metallothionein into the genetic pool of the
specific animal or livestock which helps them to increase
their efficacy in milk production and also in their growth.

20. Use of animals in experiments cause great suffering to
the animals.
Risk whether they cause harmful effect on biodiversity
and overall impact on environment .
Manipulated animals can have unpredictable results
when such organisms are introduced into the ecosystem .
Transfer of human genes into animals is great ethic threat
for humanness.
Disrupts evolutionary relationships between organisms.
Animals that are combine species an unethical
alternation of the natural order of the universe.

21. •www.internet.com
•www.tandfonline.com
•Vijayalakshmy, K., Virmani, M., Verma, R., Manimegalai, J., &
Choudhiry, U. L. (2019). Micromanipulation of embryos: An
overview.
•Hiiragi, T., & Solter, D. (2005). Reprogramming is essential in
nuclear transfer. Molecular Reproduction and Development:
Incorporating Gamete Research, 70(4), 417-421.
•Shelton, J. N. (1988). Embryo manipulation in research and animal
production. Australian journal of biological sciences, 41(1), 117-132.
•Ebner, T. (2010). Micromanipulation techniques in IVF. Journal of
Reproductive and Stem Cell Biotechnology, 1(1), 108-119.