A computer simulation of a human embryo at six weeks Credit: Science Photo Library / Alamy Stock Photo

The beautiful science of embryology

We can manipulate the cellular units of life as skilfully as a potter works clay
March 3, 2021

It’s a familiar story: the virile sperm fights its path through the hostile uterus to the passive female egg. After fertilisation, the resulting ball of cells is “totipotent,” with each unit equally capable of becoming any cell type in the placenta or foetus. Magdalena Zernicka-Goetz, an embryologist from the University of Cambridge, affronted her field by claiming this was wrong: not just the sexist metaphors, but also the assumption that the first human cells are identical. Her experiments showed that cells lean towards a particular fate, and that an embryo’s symmetry is broken from its earliest moments.

Together with science journalist Roger Highfield, Zernicka-Goetz leads us through the intricacies of modern embryology and reproductive technology. Her successes include doubling the length of time embryos can survive in the lab, building simulation mouse embryos out of stem cells and using fluorescent labels to make “embryo art.” “We are entering a new era,” she writes, “one where we can manipulate the cellular units of life as skilfully as a potter works clay.” While gene editing and designer babies raise understandable alarm, artistry in science can be both beautiful and potent.

The Dance of Life is also the autobiography of a scientist who let challenging events in her personal life inspire her work. When pregnant with her second child, an antenatal test revealed a chromosomal irregularity. It was uncertain whether the abnormality might later be eliminated. It took a decade for Zernicka-Goetz to gestate a hypothesis and prove an organism’s extraordinary capacity for self-correction. By then she had a healthy young son. The implications of this repair process for patient care are only just coming into focus.

Zernicka-Goetz upturns the cliché of the solitary genius scientist. Her success rests on tenacious intelligence, but also warmth, intuition and collaboration. These “maternal instincts” have long been ridiculed as weaknesses that make women unfit for a scientific career. In truth, a diverse science which nurtures these qualities is not only fairer, but also much more likely to flourish.

The Dance of Life: Symmetry, Cells and How we Become Humanby Magdalena Zernicka-Goetz and Roger Highfield
(WH Allen, £9.99)