Clo(w)ning Around With Stem Cells
Cloning is the
creation of cells using DNA from a single "parent" whereby the normal
reproductive process is bypassed. The clone has identical DNA to the parent.
There are three different forms of
cloning: DNA Cloning,
and Therapeutic Cloning.
The transfer of a DNA fragment from one organism to a self-replicating genetic
element such as a bacterial plasmid is known as DNA Cloning. This technology
has been around since the 1970s, and has become a common practice in molecular
biology labs today. (‘DNA Cloning’ ‘Recombinant DNA technology’ ‘Molecular
Cloning’ ‘Gene Cloning’ all refer to the same process).
Reproductive Cloning is a technology used to generate an animal that has the
same nuclear DNA as another animal. Dolly the sheep was created by
Reproductive Cloning technology.
Therapeutic cloning, also called "Embryo Cloning," is the production of human
embryos for use in research. The goal of this process is not to create cloned
human beings, but rather to harvest stem cells, which would then be used to
study human development for treating diseases.
There are two methods of cloning.
ARTIFICIAL EMBRYO TWINNING
SOMATIC CELL NUCLEAR TRANSFER.
Twinning: This method is
an old and low-tech method of cloning which mimics the natural process of the
birth of twins. In this method a zygote is manually divided into two. Each cell
is allowed to divide and develop on its own. The resulting embryos are put into
a surrogate mother where they are carried to term and delivered. Since both
embryos have developed from the same zygote they are genetically similar.
Nuclear Transfer (SCNT): This method was used to create Dolly, the cloned sheep (she was the
first cloned mammal). To make a clone, first the somatic cell is isolated from
the body of an adult. The nucleus of the somatic cell is removed and put into an
egg cell whose nucleus has been removed. The embryo is put into a surrogate
mother and is carried to term. This clone is an identical genetic copy of the
adult from whom the somatic cell had been taken.
Cloning of Stem Cells: A Solution to degenerative Diseases
What are Stem Cells:
Stem cells are master cells of the
body that can transform themselves into virtually any of the 200 kinds of cells
that exist in the human body. This means that in theory at least, these stem
cells can be 'grown to order' to help people suffering from degenerative
What is so special about stem
cells? Stem cells differ from other kinds of cells in the body because all
stem cells — regardless of their source — have three general properties: they
are capable of dividing and renewing themselves for long periods; they are
non-specific; and they can give rise to specific cell types.
How many kinds of stem cells are
there? The human body
has two kinds of stem cells: Embryonic Stem Cells and Adult Stem Cells.
Embryonic Stem Cells:
Embryonic stem cells, as their name suggests, are derived from embryos that
are developed from egg cells, which have been fertilized and then donated
for research purposes. They are not derived from eggs fertilized in a
woman's body. The embryos from which human embryonic stem cells are derived
are typically four or five days old and are a hollow microscopic ball of
cells called ‘blastocyst’.
Adult Stem Cells:
An adult stem cell is an unspecific cell found among specific cells in a
tissue or organ. It can renew itself and can differentiate to yield the
major specialized cell types of the tissue or organ. An adult stem cell
maintains and repairs the tissue in which it is found. Some scientists now
use the term somatic stem cell instead of adult stem cell. Unlike embryonic
stem cells, the origin of adult stem cells in mature tissues is unknown.
Cloning Stem Cells:
The first big problem
with stem cells is where to get them. Everyone has stem cells — they exist in
the bone marrow. For example, new blood cells are constantly regenerating. But
in adults and children, these are already partly specialised. Many researchers
doubt that they are truly capable of developing into any kind of cell.
The second problem is
ethical issues. Scientist, sociologists and theologians wonder if it is right to
tamper with nature.
To create human embryonic stem cells for
research, some of the blastocyst's cells are isolated, harvested and allowed to
grow in a separate dish. To turn them into long-lasting stem cell lines, the
cells are fed special growth factors. The embryo is destroyed in the process.
Disadvantages of Cloning Stem Cells:
There are many ways in which human stem cells can be used. However, there are
many technical hurdles between the promise of stem cells and the realization of
these uses. These problems can only be overcome by continued intensive stem cell
Cloning of Stem Cells
can cure some of the most serious diseases like cancer.
Cloning stem cells
promises to one day eliminate birth defects.
Cloned human Stem
Cells can also be used to test drugs.
Stem Cells can be
differentiated into specific cell types to treat degenerative diseases like
Stem Cells can be
used to replace old and diseased tissues and organs of the body.
While extracting a
human embryonic stem cell for research, the embryo from which the stem cell has
been removed is destroyed.
Not enough is known
about Stem Cells to differentiate stem cells.
Tremendous research needs to be
done on Stem cells before we can reap the benefits of this new frontier in
science. Society also needs to address the ethical issues involved in it. But if
it is possible to achieve and clone stem cells to perfection, then it would be
the greatest leap in scientific history.
Scientific American (Magazine) 16/12/01, 30/04/01, 09/06/03
Popular Science (Magazine) 14/11/02
New Scientist (Magazine) 24/07/03
Genetics today by Jagjit Singh
Gene Play by Parul R. Sheth
Science (Magazine) 08/03/02
Time (Magazine) 16/02/01
Indian Express (Newspaper) 11/08/03
G O T C H A !
-Mithila Mehta --Std. 10
We live in an insane world- there is a day dedicated to everyone – from
Receptionist’s day (12/2/04) Nurses’ day (6/5/04) Tax day (15/4/04) Boss’s day
(16/10/04) and of course not to mention April Fool’s Day…!!!!!!
April fool’s Day at BIS is in a league of its own…and if I were to say that
April fool's Day at BIS is nothing out of the ordinary-I would be lying.
Although everyday at BIS involves so much mischief and so many pranks that April
fools day is a daily year-long phenomenon, we BIS kids are in fact smart enough
to think of that extra eyebrow-raising outlandishly-daring outrageously-unheard
of prank for this extra-special day (I get an award for using all those hyphens
in a single sentence!)
So here is the 411 on Aprils Fool's Day 2004 (with a few exaggerations I of
The most ingenious and inventive class was by far STD 7 (According to my
brother, they pulled a total of 7 pranks on the teachers) From creepy crawly
spiders (fake of course) to hiding in the class cupboard and then pouncing on
the unassuming teacher, they did it all… A couple of 10th Std kids
did try to sabotage STD 7’s carefully designed plans by telling the teachers
about them …how very mean!!!~!
And of course STD 7’s masterpiece ---The entire class, save a dozen children
picked up their bags and hid in the adjoining music room. When Ms Khubi reached
their class for her period, she was informed by a group of straight-faced 12
year olds that the rest of the class was "absent". (Yep-- they definitely
deserve Oscars- If I had been there I would’ve been dying with laughter !!!!!J
) Ms Khubi was initially stumped but soon caught the prank when she heard
muffled giggles from the music room…. One up on the teachers!!!
STD 10 were not left far behind either…we wrote a letter supposedly from Ms.
Daruvalla to Sir Ghosh, telling him that " I am sick and tired of Class 10. I do
not wish to have any interaction whatsoever with them in the future. I have
developed a severe backache thanks to this class. Please see that Sir Yadav is
made their class teacher" (I’m not too sure of the exact wordings now- but you
get the picture) And sir Ghosh actually took the letter seriously!!!! Gotcha Sir
But the teachers had plans of their own!!! Ms. Pinto gave Std 10 a Julius
Caesar test… which we later realized was a joke when we read the question, "
Relate the Ides of March to April Fool’s Day !!!!!!!!!" hahaha on you Std 10……..
Well it must seem to you by now that BIS kids are a bunch of devious, unruly,
wild and mischievous tricksters, but I assure you, no, no, no we are not. We are
sweet and kind and sincere and wonderful and creative and bright and intelligent
and inspiring and amazing and… oh ok so you guys get the message….Anyways…HAPPY
APRIL FOOLS DAY!!!! (writing in CAPS is looks awesome!!!…) and just an
afterthought--- considering so many people like me love this day so much,
shouldn’t it be declared a national holiday or something???