John Sulston (1942–2018)

Any scientist would be proud to have changed the world. John Sulston changed the way we think about biology not once, not twice, but three times: first with his elucidation of the C. elegans cell lineage, then in pioneering genome mapping and sequencing, and lastly through his leadership in promoting open data. Along the way, he showed us how science should be done and how life should be lived.

I met John at the MRC Laboratory of Molecular Biology (LMB) in the early ’70s, where he was a staff scientist. He had been drawn to the LMB by Sydney Brenner's visionary project on C. elegans. After earning undergraduate and graduate degrees from Cambridge University, John did post-doctoral work with Leslie Orgel at the Salk Institute probing the origins of life. By the time I arrived at the LMB, John had devised a method for preserving worms in liquid nitrogen and estimated the worm genome size at 20 times that of E. coli’s. He was applying some of his post-doctoral experience to investigate the neurochemistry of different neurons. While looking at dopamine-containing neurons, he became interested in how the worm detects light touch. But the sharpened wooden sticks that we used to manipulate the worms were blunt instruments, so John devised a simple but elegant tool—one of his eyelashes glued to the end of a toothpick—which allowed him to gently stroke the worm. Soon he had mutants that failed to react to this touch, pioneering the study of mechanosensation in the worm.

In follow-up studies he recognized that the adult worm has more cells than a newly hatched larva, something that contradicted the prevailing view. Because the worm is transparent, John was able to observe individual cells under a microscope, directly …