|
How was Dolly
cloned?
Advances in cloning higher mammals beyond an primitive
embryonic stage may be a formidable challenge. Genes in cells at the
earliest stages of embryonic life carry the encoded knowledge that
instigates cells to develop various parts of the body.
The team of Scottish
scientists succeeded in the first live birth of a healthy sheep
cloned from an adult mammal. The team scraped skin cells from the
donor sheep (sheep A) and these cells were temporarily starved of
nutrients to cease cell development. An unfertilized egg was removed
from second sheep (sheep B) and its nucleus was removed to eliminate
genetic characteristics. A skin cell from sheep A (containing a
nucleus with genetic material) was fused with the unfertilized egg,
which was got from the sheep B. The egg, now with a nucleus, began
dividing and was placed into the uterus of the surrogate mother
(sheep C). This embryo developed normally and was delivered safely.
This sheep then came into the world in Feb 1997.
It is seen that most of
Dolly’s characteristics are that of sheep A (the donor). The
creation of Dolly exemplifies a unique advance for the cloning
technology, but this has lead to a deep contemplation about human
cloning. This technique can also be used for the surgical
transplantation of human organs.
What is the future of cloning?
The inescapable question raised- "If other mammals are
cloned, why not humans?"
Why are people intimidated by the idea of human cloning? There are
various ideas expressed on this issue.
Firstly is
human cloning really possible? If it is then why are people so
apprehensive about cloning? Why is that we react so strongly against
it? We never react negatively when identical twins are born. Here
the twins share all their genes while in Dolly’s case it was
different. Dolly possesses genes that came not from the parent but
from the donor of the egg, which received the nucleus from the
"parent". Therefore the conclusion would be that she is not
identical to the parent.
Some people have welcomed
the idea of cloning wholeheartedly as they see a bright future of
the improved farm animals. But it still remains a controversy when
it comes to humans - the valid argument being that we could foresee
a quick generation of improved farm animals but can we clone useful
politicians or leaders to rule the world?
Prohibition of human
cloning has already taken place in many countries. But research
shows that cloning can be extremely helpful in finding ways to
encounter genetically inherited diseases. It could also be a big
break through for the development of drugs. |
