Orgel, Crick and Sapienza

Date:
1980
Reference:
PP/CRI/H/6/13/3
Catalogue details

Licence: In copyright

Credit: Orgel, Crick and Sapienza. Source: Wellcome Collection.

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    sequences whose deletion or extensive alteration will usually produce a small effect, such as a change in the local rate of recombination. In some cases close similarity of two sequences may be important, while the base-sequences themselves may matter hardly at all — for example, within the introns of two neighboring versions of a gene. The word junk is perhaps too broad to cover all those cases for which the effect of sequence on the phenotype of an organism is small or zero. We hope a more precise terminology will evolve as the facts become better known. The work phenotype has also caused difficulties in spite of Doolittle and Sapienza's careful use of organismal phenotype I to make their meaning clear. We obviously need two words: one to refer to the phenotype of the organism and the other to apply solely to the phenotype of the parasitic DNA, a distinction we would certainly make in the case of a true parasite. For the former we would suggest organismal phenotype and for the latter, U- following Cavalier-Smith, intragenomic phenotype, but we would allow the word phenotype alone to be used when the context makes the meaning clear. In our original definition we said that selfish (parasitic) DNA...had two distinct properties. (1) It arises when a DNA sequence spreads by forming additional copies of itself within the genome.