"What is a gene?"

Date:
[1956]
Reference:
PP/CRI/H/2/7
Catalogue details

Licence: In copyright

Credit: "What is a gene?". Source: Wellcome Collection.

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    My title is what is a gene ? but what I really want to talk about^ls some recent work on the fine-s tructure of the gene; Work which may lead us to understand more about the fiHssaixmstiaxH lk¿ molecular basis of genetics and perhaps something about^that genes act. Let me first sketch for you the classical picture of the gene. You can find this in any elementary textbook of genetics. It starts by describing some simple breeding experiments - usually the historic experiments of Mendel on peas - an4 shros how they can be explained by a straightforward theoretical scheme. Then the complications due to recombination - as it is called - are introduced, and finally the reader learnâ how all these ideas can be understood in terms of the chromosomes, the small thread-like bodies within the nuclei of cells. The chromosomes carry the hereditary determinants, and the genes, the units of heredity, are strung out alonsr the chromosome, in a linear order, like beads on a string. The gene, then, is the unit of heredity. It is the building brick of the material passed on to a child from its parents, <W. ÌM ùi tkioe fixe* half from each of them,,which mainly determine! the sort of ; Ujt J child it is. It is not known how many dlfferent^genefc there are, but each human being 1 probably has more than 10^000 o£~&kefl%. Ho^ts. That is the standard picture - but I want to explain to you that the gene - the gene in the very old-fashioned sense Sit of the indivijßle unit of heredity - has been split, and split decisively. To do this I shall discuss a simpler system so that you can grasp the essential poits more easily .