So we spent considerable time on studying different MHCs in different vertebrate classes, specially in the mouse... in the fish, and it became clear that the MHC could be easily... relatively easily followed, all the way to sharks, which were the one class that was considered to be most primitive of the jawed vertebrates... vertebrates that had jaws. But there was another group which was more primitive and those were vertebrates without jaws which were represented by hagfish and lamprey, and the question was do these groups... do these animals have also MHC and by extension the immune system that was based on MHC?

We spent a lot of time on that question trying to first detect the MHC by a variety of means and when the gene technology became available to look for the genes themselves in these animals, but we couldn't find any. Of course finding or not finding something... if you are not finding something it doesn't mean that it's not there because unless the whole genomic sequence became available, this could not be decided. But we could not afford to do... to sequence the genome of the lamprey, so we took the next step available and we, in this case, was primarily Werner Mayer and Tania Uinuk-Ool... Tatiana Uinuk-Ool... I'll say that again because I don't want that I say it wrong... Tatiana Uinuk-Ool, who collaborated with Max Cooper in Birmingham. Actually, the collaboration started when Max was on a site visit in our institute... one of the member of the committee that evaluated the work of our institute and we presented our efforts to study the lamprey immune system and he suggested well, why don't you isolate the lymphocytes or something that looks like lymphocytes and then look at them? Well, we didn't have a means of doing that but he had an excellent equipment that... very specialised and highly evolved, who... which could be used for that purpose. So we agreed to collaborate on that and indeed the collaboration proved to be very fruitful.

So the idea was to isolate using this machine cells that would have the properties of mammalian lymphocytes. The equipment could be set up in such a way that it would isolate from blood or from tissue cells that have... appear to have the properties... physical chemical properties of the lymphocyte, and then use this to isolate RNA or messenger RNA which codes for genes that are expressed in these lymphocytes. So this was done and then the genes were cloned, or well, some of these genes were cloned and sequenced and we looked for MHC or any other sign of the immune system that is based on the MHC. Well, to make a long story short, we didn't find it and I think after an extensive search, at least I am convinced that it is not there, that the jawless vertebrates do not have an immune system of the kind that other vertebrates have. So that would mean that the immune system evolved in vertebrates but not from the beginning, that at a certain stage when the vertebrates acquired a jaw the immune system evolves at the same time.  And I think there are a number of other findings that support this finding... that it extended to other groups of jawless vertebrates was then shown by other people in particular, Masanori Kasahara and his group.