A Canadian dentist, Dr Michael Zuk, had bought the extracted tooth of the late British pop musician John Lennon from his maid for $ 31000, and now he wants to extract DNA from this tooth and bring Lennon back to life by cloning. This news hit the headlines, since Lennon was a member of the famous quartet, the Beatles, who were a rage in the 1960s and 70s.
Can this be done? Can Lennon (or anyone else for that matter) be cloned? The answer is yes. A clone is a cell or an organism that is produced asexually from an ancestor, to which it is genetically identical. Thus the clone of Lennon, produced today, will be genetically the same Beatle John Lennon.
How is this done? The procedure was first illustrated by another Brit, John Gurdon, just about the time the Beatles began their career. Gurdon isolated the nucleus (which contains all its genes in the form of DNA) from the skin cell (not tooth) of a frog and kept it aside. Next he took the egg of another frog and inactivated its cell nucleus containing its DNA using irradiation. This egg was now fertilized in the lab by inserting the skin DNA of the first frog. In time, out came a tadpole.
What Gurdon did was not the usual ‘sperm meets egg, fertilization happens and out comes the baby’ procedure. The frogs did not mate sexually, because when they do the male frog injects not its skin cells into the egg but its sperm cells. Sperm cells are a set of what are called germ lines, used specifically for reproduction. (Egg cells too, of the female, are likewise germ line cells). DNA in the Gurdon experiment here came not from sperm cells but from the nucleus of its skin cell (which is called a somatic cell). What Gurdon did was in effect generate a clone of Frog 1, which gave its somatic cell DNA. The tadpole is thus its clone. Frog 2 did not contribute any of its genes to the baby; its egg was simply an empty reaction vessel.
Moving further to the 1990s and to mammals, Ian Wilmut of Edinburgh did a similar cloning of sheep. He and his associates took a somatic cell from the udder of a white-faced ewe (call her Molly), isolated its nucleus and kept it aside. Next they took the egg cell of a black-faced ewe (call her Polly) and removed its nucleus (and thus all of its genetic content). Now they inserted Molly’s nucleus into Polly’s emptied egg cell and made the embryo. Next they brought a third ewe (call her Holly) and, using her as the surrogate, placed the above embryo into her womb. In time came the white-faced lamb that they named Dolly. (Considering that her genetic provenance came from the mammary glands of Molly, Dolly was named after the amply bosomed actress and model Dolly Parton). (For the inquisitive, note that all of them, Molly, Polly, Holly and Dolly are female. The only male DNA of Dolly came from Molly’s father’s DNA contained in her somatic cells. Here then is a set of posers: is Molly both Dolly’s mother and sister? Can Polly not claim motherhood? And what about Holly, is she just an incubator?)
From Lamb to Lennon
If we can clone frogs and sheep, why not humans? The technology is available and standardized. Michael Zuk is not the first to think of it. Indeed, immediately after Dolly was cloned, a reporter apparently went to the Vatican and asked a Cardinal there: “Father, we hear that a cathedral in Turin has the shroud that covered Jesus Christ after his crucifixion. What is your reaction if someone were to isolate any DNA of Jesus that is still left in the shroud, clone him and bring him alive?” The father’s reply was simple yet telling. He said: “my son, you would have cloned Jesus’s body, not his soul.”
Man does not live by body alone
Leaving apart several other controversial issues related to human cloning, the above answer captures the utter futility of cloning humans. Man does not live by body alone, he needs his brain too. DNA makes the body and the hardware of the brain. But what goes into the brain is interaction with the external world. Culture is not coded in our DNA. Experience, education, environment — all these matter. John Lennon of the 1960s was not only a product of his parents but was also immersed in the world of his time, absorbing from it and giving to it. If the clone Lennon of the 2020s were to sing “I want to hold your hand,” would it be the same as what the original Lennon sang? The Cardinal has given us the cardinal answer.