Dot writes: here’s an interesting weird thing from a book on pregnancy that I’m reading (A Visitor Within, by David Bainbridge). Apparently, although unfertilised human eggs do sometimes start to divide, the pregnancies don’t progress because in humans (and other mammals) genes from the sperm are required to form the placenta. But in 1995 a research team in Edinburgh were studying a one-year-old boy, ‘F. D.’, who had a rare, though not debilitating, set of abnormalities – one side of his face was smaller than the other, his uvula was split, and he had mild learning difficulties. They tested cells from various parts of his body and got the following extremely odd results: from a blood sample, he seemed to have the genes of a girl, but the skin on his leg contained the genes of a boy. So they thought he might be a chimaera – a mix of male and female. But then they discovered that all the cells came from the same egg.
This led the scientists to the conclusion that F. D. was. in fact unique. Half of his cells are parthenogenetic. He is a male/parthenogenote chimaera.
The team then pieced together the first few unusual days of F. D.’s existence. His mother produced an egg, and this egg misguidedly started to divide before it had been fertilised – it split into two. Then something extremely unusual took place. A sperm fought its way into the zona pellucida and fertilised one of the two cells. The fertilised cell started to divide and produced the half of the cell that is ‘normal’, and the unfertilised cell also began to divide and ended up producing the half of the boy that is parthenogenetic….Obviously, F. D. must have made a placenta, or he would not be with us, so a lot of paternal-gene-containing ‘boy cells’ must have made it into the placenta. (p. 37)
On which my considered comment is “Woah, dude!”
I haven’t got very far through the book. So far it’s full of jolly facts, detailed enough for me to feel I’m learning something but not too much for my poor Arts Faculty brain. As you’ll notice from the extract above the author is drawn to metaphors of struggle (that heroic sperm!) and to talking about unconscious processes as though they were conscious processes. I have a feeling I could find this cumulatively irritating as I go through the book. However, it’s fun so far.