Platypus, Ornithorhyncus anatinus

Dr Adrian Friday, retired Curator of Vertebrates, writes:

From 1971 through to 1976 a team of four of us were working on the structure, function and evolution of the muscle protein myoglobin. Myoglobin, like the red pigment of blood, haemoglobin, reversibly binds oxygen. However, myoglobin is sited not in the blood, but in muscle, and it is able to store oxygen for use in muscular activity. As you might expect, it is particularly important in diving mammals (like whales and seals). In the early seventies, a three-dimensional structure for myoglobin had been determined, and a good deal was known about its functional aspects. We had the advantage that we had access to John Kendrew and especially Max Perutz (both Nobel prizewinners for their work on proteins) who had been involved in determining the structure by X-ray crystallography.

Our team of four was made up of two medical doctors and two zoologists. The two biochemical medics were Hermann Lehmann, then Professor of Clinical Biochemistry (and Head of the Medical Research Council Unit for Abnormal Haemoglobin – known universally as ‘the Abnormals’) and Alejo Romero-Herrera (now Alex Roher, naturalised in the US and working on Alzheimer’s Disease). The two zoologists were Ken Joysey, then Director of the University Museum of Zoology, and me; I was very much the baby of the group, both in age and achievements!

Originally, the two biochemists were interested in myoglobin because it might have been the clue to one form of muscular dystrophy, although, as it turned out, the problems are elsewhere – and that’s another story. The idea was that looking at the sequence of amino acids that make up the myoglobin of other mammals might give clues to what changes were ‘permissible’ in the protein and what changes were not. As comparative data accumulated, there was inevitably an evolutionary dimension to the work, and hence we two zoologists were recruited to look at this aspect. The attraction of including rather more exotic species was too good to resist: an Australian group had sequenced the myoglobin of the echidna (spiny anteater) but we hoped to determine the sequence of the duckbill platypus. There was a small problem in that we hadn’t got a platypus! However, the then president of The Royal Society, Lord Todd, was about to embark on an official trip to Australia.

You can guess the rest: when Lord Todd was asked what he might like as a memento of his trip, we had briefed him to ask for a fresh, dead platypus. Accordingly, he arrived back in Britain with a platypus that had suffered an accidental death, but was in very good condition. I took my dissecting instruments up to Addenbrooke’s Hospital, where the laboratory was, and removed enough muscle for the biochemists to do the work. When I had finished looking inside the platypus (and fascinating it was, too) we stitched it up and freeze-dried it in the Museum, where it was put on exhibition. So there it is: a platypus with a pedigree.