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DNA Patterns

DNA is only part of the answer to how biology actually works


You know, that’s an incredibly hard question, it would be like asking me what is my favourite opera.  I mean, how do you go about comparing Janacek with Benjamin Britten, with Strauss, with Mozart, Tchaikovsky, I don’t know, Monteverdi, Jesus, I mean, you know, how can you do it? Reinhard Kaiser!  You know, and the same thing for me applies in science.  Perhaps it’s really the fact that I’ve got the attention span of a hamster and I just find so much stuff interesting that I think that all I can really do is, I don’t know, confine myself to a time period, and say the last week.  One of the things that I’ve been talking about for quite a while is the profound connection, in a sense, between chemistry and biology and the idea that DNA is only part of the answer to how biology actually works.  And there’s a remarkable paper in Science, this week in fact, in which Turing patterns have been found in the way in which certain organisms are actually able to construct fingered, digitated hands.  And Turing in 1952 made this extraordinary prediction that if you took chemical reactions and the speeds at which they happen along with diffusion, in other words the sort of random motion of molecules through a medium, that the combination of those two processes would actually lead to structure.  And, you know, remember that DNA is not the answer because DNA doesn’t code for fingers, it doesn’t code for blonde hair, what it codes for is proteins and so there’s this kind of disconnect. And what they’ve done is they’ve actually found a connection between certain genes and Turing patterns, and this is really quite exciting.  It also is very controversial because one of the things that Turing said was that you need to have some kind of chemical messenger molecule - what he called a morphogen - and the morphogens have remained extremely elusive.  Anyway, that paper caught my attention because, you know, it just seemed so kind of beautiful and a further indication of Turing’s prescience.


- Prof Andrea Sella