93rd Congregation (2024)

On the 21^st of January 1665 my sevenfold-great-uncle Samuel Pepys stayed up notably late – until well after midnight. He was reading a large and sumptuous book he had just acquired. It was written and illustrated by Robert Hooke and had just been published, under the auspices of the Royal Society. It was called Micrographia, and it contained very large drawings of very small things as viewed through a microscope. Pepys wrote that it was ‘the most ingenious book that ever I read in my life’. Its remarkable drawings (Hooke had been apprenticed with Lely, the leading court portraitist of his time) made it a best seller – the human flea is an extraordinary, if alarming, creature when seen vastly magnified– but perhaps the most influential illustration is much less artistically striking. It shows the appearance of a thin slice of cork which, when magnified, resembles the structure of honeycomb – so much so that Hooke called the tiny box-like structures of which cork is composed, ‘cells’. It was the first time that anyone had seen and reported on these tiny, yet crucial, biological units.

The life you can see around you, whether moss or redwood and from gnats to whales, starts out the same way: as a single cell. It doesn’t matter whether we’re destined to be gigantic or tiny. We grow to our adult size through successive cell divisions. But what determines whether or not a cell will divide into new cells, which themselves divide into yet more cells and so on? Why don’t they go on for ever, proliferating exponentially? Proper control is essential for normal growth: we not only need to start growing, but we also need to stop at the right point. The ‘cell cycle’, which controls whether or not cells divide, is thus central to normal development. Failures might not only make us the wrong size, or wrongly proportioned; cancers, too, are a form of uncontrolled cell proliferation. So understanding how it works, and how it can go wrong, is a central question in biology. Professor Paul Nurse’s experimental life has been dedicated to resolving this question. It wasn’t all plain sailing.

Paul Nurse was born in Norfolk but while he was still young his parents moved to the Greater London district. There he attended a primary school which he distinctly enjoyed and to which he walked each day. That journey, often made on his own, took him through some undeveloped land and across a large park and what he saw around him – and above him – kindled his interests in the natural worlds of biology and astronomy. He passed the national eleven-plus exam which split secondary schooling into two streams and sent him to the nearby grammar school, which lay within the highly selective and academic branch of the English school system of that era. Yet it was, for various reasons, less welcoming than the place he had left. He nonetheless retained and developed his interest in biology, and was good at it. That should surely have taken him to university. But he wasn’t good at French.

You may well wonder why that should matter to a would-be biologist, but it did. Successful applicants to a UK university in the 1960s needed not only to be proficient in their specialist subject but also to have a basic modern language qualification – most commonly French, which was widely taught at school. If your French wasn’t good enough, it didn’t matter how good you were at your actual degree subject: you wouldn’t get a place. In some ways that was an admirable requirement for a literally insular nation lying a short distance from the European mainland. But it could also be disruptive. For the young Paul Nurse it meant that his initial route to biological research was through working as a technician rather than becoming an undergraduate. His workplace was a microbiology laboratory. It belonged to the Guinness company – a distinctive giant among brewers. And brewers know a lot about yeast.

Making beer is both an art and a science that humans have practiced for thousands of years. The principle is simple: extract sugars from grain to make a sweet liquor, and add yeast, which ferments it into alcohol.  Strains of the same saccharomyces species make the alcohol in beer and wine, and the bubbles in bread. A lot of work has gone into finding strains that give quick (or slow) fermentations, or impart different flavours, or can be dried and reconstituted so that we get the tastes, textures, and convenience that we want. But beyond that, yeasts have become very important to microbiologists, because they are eukaryotes, which means that they are representative of plants and animals generally, yet they are also single cell organisms. That makes them easy and safe to grow, maintain, manipulate, and study in a laboratory, so much so that that some consider them the ideal model organisms for modern molecular biology. Finding oneself in a brewer’s laboratory could thus offer more opportunities than just the raw material for parties. As things turned out, Paul Nurse’s basic duties in the Guinness laboratory took up only two days a week – outside that, he conducted his own research. This was because he had a perceptive lab head who could spot talent and saw it, and found a way to encourage it. The results captured the interest of a Professor at Birmingham, called John Jinks, who found a way to make a place available – French or no French. History has demonstrated that it was a seriously good decision.

Birmingham provided not just intellectual excitement but also an opportunity to explore possible futures in biology. Ecology? Fascinating in theory, but far too cold in practice out in the field (or more specifically, in the sea: laboratories represent a more comfortable environment both for experimenters and their subjects). Animals? Paul Nurse’s first introduction to that cell cycle which became his research life was through undertaking a project on the division of fish eggs – but one that he characterizes as having been “disastrous”. Plants? Perhaps they might offer a better way into developmental biology. So that was the initial route that he took – though turning his research programme into the extraordinary success that it eventually became took time, travel, flexibility – and resilience.

From Birmingham he went to the University of East Anglia as a research student studying molecular changes during the cell cycle – which took him back, once more, to yeast. At times, he found the sheer difficulty of making progress in experimental research deeply disheartening, but he stuck with it and started to plan a post-doctoral career developing further ideas for using a genetic approach to understand cell reproduction in yeasts. This meant building on a genetic approach pioneered by Lee Hartwell in the US, but translating it into a different yeast species – which itself meant mastering and combining techniques developed in two further laboratories – one in Switzerland and the other in Scotland.  Yet within a matter of presumably fascinating yet frantic months, the key connections were made and the new project was up and running; from it emerged the identification of a key controller of the yeast cell cycle, the cdc2 (or cell division cycle 2) gene. From this, and from its connections to work going on in other model systems, developed a cascade of further experiments and observations, including his own team’s identification of the human version of the gene. In 2001 this extraordinary body of work was recognised by the award of a Nobel Prize, shared with Tim Hunt and Lee Hartwell for their discoveries of “key regulators of the cell cycle”. Paul Nurse – by then Sir Paul Nurse – was 51. If he hadn’t told us how hard it was at times that brief summary would make it look as easy as floating among the clouds (which, as a serious glider pilot, he can tell you isn’t as easy as it looks either).

The autobiographical details that tell his story on the Nobel Institute’s website exemplify eloquence and generosity, and end with a startling coda, which you should read for yourselves one day. He conveys not only a passion for science – both its beauty and its practical importance – but also a deep sense of our responsibilities as communities of scientists. The exceptional importance of his research has led to honours and awards far too numerous to list here, and I shall touch only on a small subset of the positions he has held, plus one that he didn’t hold: years ago, I tried to persuade him to return to Oxford to take up a Statutory Chair; I failed. In the event, his still grander roles as President of the Rockefeller University, his appointments in the major cancer research charities in the UK, his current position as Director of Europe’s biggest biomedical laboratory, the Francis Crick Institute in London – as well as his time as President of the Royal Society, an office once held by Samuel Pepys, with whom I started this citation – all reflect widespread recognition and deep appreciation of his commitment to science, to education more generally, and to humanity. I represent the admiration of many when I say:

Mr Vice-Chancellor, it is my great pleasure and my honour to present Sir Paul Nurse for the degree of Doctor of Medicine honoris causa.

Citation is written by Professor Nick Rawlins,

Pro-Vice-Chancellor / Vice-President (Student Experience) and Master of Morningside College