A sheep. A scientific revolution. A clone!
March 10, 1997. An article in the Times Magazine made instant sensation all around the world. Even the medical community was not at ease since something implausible had happened that if pursued had the capacity to change our world forever and give humans the power to literally control and alter humanity.
The news was about a sheep, the first mammalian clone made from an adult cell. She had three mothers and no father. She was born without involving any sex, almost like a sci-fi creation or a fallen Angel. She had the exact same genetic information as her mother. Her name was Dolly.
14 Feb, 2003. She was exterminated.
What is Cloning?
Cloning simply means making exact copies. Just like photocopying. And depending on what you clone there are various types of cloning.
Nature however produces natural clones. Lower life forms like the bacteria and the viruses clone naturally by asexual reproduction. Asexual reproduction means that organism can simply divide into two, almost magically, and then four, and then sixteen and so on and on. Each successive generation is a clone. There is no male and no female and no sex and no fun of course!
But there are small aquatic animals like Rotifers which can chose either to produce by sex or by asexual reproduction to produce clones! Nature does this ambivalent trick naturally. How? No one knows.
Anyway, it is ‘sex’ that is fun. But sex is also a problem in making clones in higher forms of life that reproduce only sexually. Higher life form like cows, dogs, and humans etc. reproduce by sex. And sex makes sure that the genetic information of the father mixes with the genetic information of the mother to make a new hybrid animal, with mixed information and characteristics of both the parents. How many times we all have heard that ‘Oh! Her eyes are just like her mother while her complexion is like her father’s’. Nature mixes the two information as if in a jar and boom comes out a new hybrid organism. Nature is the best craftswoman. By this sexual process, nature prevents cloning in the higher animals.
Plants also reproduce sexually. But people have been cloning plants since ages by a method called grafting. It is very easy and is still a common practice among the farmers.
So why not artificially clone animals?
First grafting doesn’t work in animals. Although, cloning DNA and cells and embryos in animal is quite easy, and that too, science has been doing since quite a time, but cloning an entire animal was deemed almost implausible.
But on 5th July, 1996, the implausible happened. Dolly was born. And the next year, by March, Time Magazine made this a sensational public news.
The cover said ‘Will There Ever Be Another You?’ This was anyway a hyped-up caption, but it worked and people were taken aback by shock and awe for science. Dolly had three mothers and no father. An animal born without sex and a photocopy. This was unthinkable. Almost a miracle that science achieved. Dolly was instantly a superstar covered by all TV channels worldwide.
What was so Special in Dolly?
Of course, the first thing is she did not have any father and that was really special. However there were more important reasons.
Dolly was not the first animal to be cloned. Many frogs, mice, cows and even sheep were cloned before her. But all those were cloned from an embryonic cell. What made Dolly special was that she was cloned from an adult cell. And this is no trivial issue.
The embryonic cell is found in the womb of the mother and made by fusion of the father’s sperm and the egg cell of the mother. The difference between embryonic cell and an adult cell is that embryonic cell can keep on dividing and most importantly have the capacity to differentiate and develop into different organs. In simple words, if you look inside the womb of the mother on the first day after the pregnancy test is positive, you will see a cell or ball of cells called as the embryo. This ball of cells later divides and differentiates and develops into full blown baby with different organs like heart, lungs, brain, skin etc.
The embryonic cells can differentiate into any organ as they like and but the organs cannot differentiate into anything they like. Otherwise you would be getting teeth out of your hair or skin grown in your liver. The organs have the adult cells which loose the capacity to differentiate like the embryonic cells. Why is that? No one is clear as of yet. But what is clear enough that embryonic cell has the capacity to differentiate while adult cells loose this capacity. Scientists think that this was due to the difference in the genetic information they have. Embryonic cell was considered to have a holistic genetic information to differentiate into any organ it likes, while adult cell only specific information concerned with the organ they make.
When Dolly was announced, cloning from an adult cell was a shock to the scientific world since their theories were about to have a paradigm shift. An adult cell is not supposed to differentiate but, in cloning Dolly, it did!
So, How was Dolly Made?
Dolly was “built” from three different female sheep and no father and of course without sex.
Her genetic mother — the sheep from whom she was cloned in the common understanding of the term — was a Finn-Dorset sheep. Researchers took a sample from the donor sheep’s mammary gland adult cells. The genetic material that has all the information of the adult cell was extracted from those mammary cells and set aside.
Dolly’s second “mother” sheep was a Scottish Blackface, which donated an unfertilized female egg cell. The genetic material from that egg cell was likewise removed and made hollow.
Scientists then implanted the complete genetic set from the Finn-Dorset into the hollow egg cell of the Scottish Blackface and ran a slight electrical current through it. The egg cell then as if by magic began to reproduce itself and scientists implanted this new cell mass into a third mother — a surrogate mother — using standard IVF techniques.
And boom… Dolly was born on July 5, 1996, and was announced to the world on February 22, 1997.
You can see, the adult cells had lost capacity to differentiate due to some changes in its genetic information, but now suddenly the genetic information when put in the other hollow egg cell started to differentiate. It should not have happened by all the science we know, since it is the genetic information that controls the differentiation and division of the cell. If the genetic information did not differentiate the adult cell, then it should not differentiate any cell, just as if software cannot function as a browser in Dell, then it cannot do so in Apple either.
But this is what was happening. The Adult cell genetic information which lacks the differentiating capacity was somehow differentiating the hollow egg cell when put into it. Magic!
Scientist speculate that the hollow egg cell somehow reprograms the adult cell genetic material. There are other conjectures but on one knows exactly what is happening.
Some Reservation and Unexplained facts
The news of Dolly was indeed an instant hit. But with some reservations and unexplained facts:
1. There were over 270 attempts to make dolly and all failed except for Dolly and two other lambs, both of which died shortly after birth. This was quite high failure rate, prompting the question as to why the process was so hard to do.
2. For an adult cell to become an embryo, all its genes have to be reprogrammed. This reprogramming would not take place in the adult cell itself because the cell is already mature and in a dormant state. But there seems something in the hollow egg cell which prompts the reprogramming of the genetic material. What is that “something” is totally unknown? Not only do we not know how the genes are getting reprogrammed, but also, we do not even know what the “program” is.
But, why clone at all?
Scientists claim that cloning can be of many therapeutic uses in future. Certainly, cloning can be fun, if not of therapeutic use. But such an expensive fun would be foolishness.
Cloning can be used to produce high variety of crops, high quality animals, organ transplantations, preservation of endangered species, producing healthy offspring to genetically defective parent, in cases of infertility and to cure deadly diseases like Alzheimer and cancer.
But there are disadvantages too. Cloning will lead to loss of diversity of genes and thus put humanity as great medical risk since the identical genetic information in clones will weaken our power to adaptations, which make animals subjected to great diseases easily. Since all the cloned humans will be of same genetic makeup the entire cloned population will be at risk of extinction if an epidemic occurs. Mutations will be preserved and filtered out with successive generations. And then there are a whole lot of ethical and legal issues, especially cloning the humans.
Although there are heated debates that surround the therapeutic uses of cloning, most of the uses can be safely achieved by environmental and life style adjustments. For example, deadly diseases like cancer and diabetes can be avoided by improving the life style. Endangered species can be protected by a change in habitat. High quality animals can be produced by animal husbandry. Leaving aside few genuine uses, much can be achieved by environmental adjustments. The crux of such debates is why to go on to spend millions of dollars and precious time and energy in cloning if much of the benefits of cloning can be achieved by simple methods.
Weighing the disadvantages of cloning versus the advantages, cloning seems to be a bad deal. By the way, one of the disadvantage of cloning is there will be no need of males. Males will get exterminated from the planet and females can rule. Good news however for female libs! But they will miss sex, of course, unless they are lesbians. But then cloning will not produce a lesbian clone! Or will it?
The Myths of Cloning
The clones were not identical as the scientists claimed and the newspapers and movies only hyped it up. In strict sense, Dolly was not a clone.
University of Massachusetts, biologist Jim Robol who created the clones admits:
We have had lot of people look at them and its always the question: these aren’t identical! In fact, I had a person in the, ah! beef industry, that was trying to convince me that these could not be identical because they do not have the exact same coat-color pattern” Robol says he excepted subtle differences in the animals coloration, because the patterning is due to more than just genetics, in the same way identical twins have different patterns of freckle and different fingerprints. But robin says his cloned calves have distinct personalities.
What sense do we make of clones if the clones look same but they have different identities and personalities?
Then there are environmental effect on genes which eventually does not allow clones to be even physically be the same. Jim states further:
We have had lot of people look at them and its always the question: these aren’t identical! In fact, I had a person in the, ah! beef industry, who was trying to convince me that these could not be identical because they do not have the exact same coat-color pattern.
At university of Hawaii, researchers found out that mice cloned from a single individual do not always grow the same. Some of the mice become normal sized adults while others become obese, despite being fed the same diet.
And at the Roslin institute in Scotland, the creators of Dolly, created four Dorset ram clones and reported:
…there are big differences in their behaviors, with some being much more assertive than others.
Cloned animals are also different in their internal body constitution. They are generally weak and often immune compromised and die early on due to infections. Many age faster than their genetic donor.
Not only do most attempts to clone mammals fail, about 30% of clones born alive are affected with “large-offspring syndrome” and other debilitating conditions. Several cloned animals have died prematurely from infections and other complications.
(Human Genome Project Information)
Even Dolly was euthanized on 14 Feb, 2003 because of progressive lung diseases and severe arthritis.
To sum up, clones are certainly same in their genetic makeup. But different in personalities , their internal constitution and some of the physical characteristics.
Faced with these obvious differences, what sense do we make of them as clones?