Obituary: Professor Nigel Holder

NIGEL HOLDER had recently become head of the Department of Anatomy and Developmental Biology at University College London, and was enjoying enormous success, when he died suddenly and left his family, friends and colleagues devastated.

He had started life as a botanist, but after graduating from King's College London in 1974, chose to do a PhD with me on limb development, focusing on the the development of joints and bone formation, at the Middlesex Hospital Medical School.

He made the transition with great ease and then was awarded a Nato Postdoctoral Fellowship to work on limb regeneration at the University of California at Irvine. There he rapidly made significant contributions to the mechanisms by which the regeneration of the newt's limb is controlled.

It was characteristic of Holder's exceptional abilities to master new fields. When he returned to London in 1979 he was appointed Lecturer in Anatomy at King's College where he studied how nerve cells find their targets. He was soon promoted to a Readership and then became a Professor.

It was at King's that his imaginative organisational skills were put to particularly good effect. By persuading committee after committee he managed to set up a Developmental Biology Research Centre in Drury Lane.

The unit was a novel idea and brought together in an interdisciplinary environment a variety of different groups each with their own techniques; so there were those with a more classical approach to how the embryo develops - who thought mainly in terms of cells and how they signalled to each other and how they responded - interacting with those whose natural mode of thought was in terms of molecules. The centre was, and is, a great success.

Holder's own interests now moved towards analysing development using the techniques of genetics. He was one of the first in this country to begin to use the zebrafish as a model for such studies and he soon established himself as a leader of a major group studying how mutations could affect the development of the zebrafish embryo.

His reasons for choosing the zebrafish were not only because it had a short breeding cycle and so made genetics possible, but also because the embryo is transparent and so the behaviour of every cell in the embryo can be followed under the microscope.

Holder was initially particularly interested in how the brain of the early embryo is patterned. He became increasingly convinced that a class of molecules known as ephrins play a vital role in signalling between cells during the development of the nervous system. More recently he discovered that they play a key role in the process whereby the embryo becomes segmented into blocks of tissue along its head to tail axis - blocks that later give rise to the vertebrae and body muscles.

Just 15 months ago Holder was appointed to his current position as head of department at UCL. This was a major commitment as it is a very large and successful department. Holder had been diagnosed several years earlier as having vasculitis, an auto-immune disease affecting the blood vessels. At times the effects of the illness were severe but he never complained and stoically waited for each episode to pass.

There was every evidence that his doctors had found ways of controlling it, and he threw himself with enthusiasm into his new role. He built beautiful new aquaria for his fish and won support from many funding agencies to establish a large group of researchers.

He ran the department with a touch that gained him the affection and confidence of his colleagues. It also both amused and pleased him and me that he was now the boss of his former supervisor. Holder had friends in the scientific community throughout the world; he had a great talent for friendship. He loved paintings and music and had become an enthusiastic and moderately competent golfer.

His research was going very well and he had just been awarded a new grant for half a million pounds for special equipment. He had just completed, with a German colleague, a very important review of the role of ephrins in development. He was also planning a major reconstruction of part of the building in order to establish a new Centre for Post-Genomic Research.

Holder realised that more and more, as the genome - the DNA - of humans and other organisms was worked out there would be the need to find out what all those genes were actually doing. His commitment to both science and the department was total.

But so too was his commitment to his family. He was particularly proud of his six-year-old son Daniel's poem that he had composed all on his own on a computer; he had brought Michael, his nine-day-old son, into the department on the very day that he died.

Nigel Henry Keith Holder, developmental biologist: born London 2 July 1953; Lecturer in Anatomy, Kings College London 1979-84, Reader 1984-93, Professor 1993-97; Head of Anatomy, University College London 1997-98; married 1990 Alyson Fox (two sons); died London 11 December 1998.