A spark of life

I’ve been reading about the process of cloning. Some of this process seems conceptually simple, obvious even, yet is clearly very technically demanding. For example, part of the process requires removing the nucleus from a cell and inserting it into an egg which has had its own nucleus removed (a nucleus is the part of a cell which contains the DNA, and this in turn contains the genes needed to instruct a growing embryo what to do and how to grow).

Then, a small electric shock is applied across the egg and its new contents. This shock apparently has two purposes. One is to help the nucleus ‘fuse’ to the egg and the other is to ‘activate’ the cell division process (which is what happens when an egg is fertilised by a sperm), and help the egg on its way to becoming a new organism.

This process of applying an electric shock also seems simple in one way. But it’s not obvious why it should work, and I can’t find a proper explanation in any popular account of cloning. How can an electric shock mimic the natural process of fertilisation? Why did anyone think this would work?

I find this lack of information unsettling and it seems at odds with the rest of the detailed information about cells, nuclei and so on. The account that we do have brings to mind the scene in ‘Frankenstein’ in which the monster is brought to life by an electric shock. Is that why we’re not given more information about the process, because it’s assumed that we’re familiar with it already, through reading or watching ‘Frankenstein’?

To be fair, the idea that electricity is linked to life has been around for longer than ‘Frankenstein’. When she wrote the book, Mary Shelley was influenced by Galvani’s experiments in the late eighteenth century. Galvani found that when he applied an electric shock to dead frogs’ legs they twitched, leading him to think that electricity was the vis viva, a sort of life force.

This intertwining of science and stories about bringing inanimate objects to life goes back further. The Golem is a creature in Jewish culture made out of clay and dirt who is created to protect Jews. One of the best known versions of this story is set in Prague in the sixteenth century. The Rabbi of Prague makes the Golem in order to protect the Jews in the city from anti-Semitic attacks. Here, the creature is not activated with electricity, but by having the word ‘emet’ (Hebrew for ‘truth’) inscribed on his forehead (in some versions a piece of paper inscribed with this word is inserted into his mouth). He does as he’s told and he protects the Jews, but he gets increasingly violent himself, until the Rabbi is forced to deactivate him, and he does this by rubbing out the first letter of ‘emet’ leaving ‘met’, which means ‘death’.

The fact that words are used to bring the Golem to life, and then to kill him off again, is a nice metaphor for the power of language. It feels more precise than a flash of electricity; perhaps that's because there is more information in a word than in a spark.