Abstract

You could sometimes see the flash of genius that he had when we were dealing with routine matters. When we started using cultured cells for cloning instead of the blastomeres we had been using to produce cloned sheep up to that time, we did not know how much extra power we would need to fuse the much smaller cultured cells onto the enucleated oocytes. When I asked Keith he said, “give three electric pulses” instead of the one we had been using for the much bigger blastomeres. The new fusion parameters worked immediately, removing the need for further experiments to determine the best settings for electrofusing cultured cells. We continued to use these parameters, and we produced the sheep Morag and Megan, the first animals produced from a cultured cell line the following year. This was the group's first nuclear transfer “Nature publication” and this was the enabling technology that allowed us to eventually produce Dolly. Keith always maintained that this paper was equally as important to cloning as the later publications because this proved that the theories he had were correct. However, the news of these animals and their impact was overshadowed by the Dunblane primary school massacre, which occurred at the same time that the paper was published.
Dolly, produced the following winter, was a natural progression of the previous experiment, moving from cultured cells derived from a day-nine embryo, used to create Morag and Megan, and producing four more animals from the same cells. The next stage of the experiments was to produce animals from more differentiated cells, which were from a day-26 Black Welsh Mountain fetus; two male offspring, Taffy and Tweed, were produced. Nuclear transfer experiments are limited by the breeding season of the Scottish Blackface sheep, which we used as oocyte donors, and which usually ends with the longer days of March. However, we were given the mammary cells in the last few days of the breeding season and squeezed in 3 weeks of work that resulted in Dolly!
Keith's enthusiasm for science was infectious. He loved to do things in the lab, even though he sometimes should have been doing other things. He was happiest working along with the rest of the team, and there was nothing that he would not help with. He fitted in with all of the team and would take the time to answer their questions and explain the experiments to them.
When Dolly's birth was finally announced, Keith did not seek the limelight and allowed others to explain the significance of the animals. I don't remember him having many interviews with the media, but that's the kind of person he was! Perhaps he was too modest, but I think he had his work/life balance just about right. He was the kind of person who you might not see for ages but when you met him it was as if you had seen him yesterday.
The team went on to produce the first transgenic animals produced by nuclear transfer, with the results published in Science this time. These were three very special years in my life as well as for the team—we had two Nature publications and one Science publications and had changed science forever.
Keith packed a lot into his life and never took himself (or others) too seriously. We have all lost a great friend, colleague, and scientist. He certainly left his mark on anyone who he came across in his life, but most of all he will be remembered for his Science!
