| 释义 |
prototroph Genetics.|ˈprəʊtəʊtrəʊf, -trɒf|
[f. as next.]
A strain (usu. of bacteria or fungi) which can grow on the simplest medium necessary for the growth of its species, without supplementary nutrients.
1946Ryan & Lederberg in Proc. Nat. Acad. Sci. XXXII. 172 We propose to designate as a prototroph any strain which has the nutritional requirements of the ‘wild type’ from which it was derived irrespective of how it became prototrophic. 1952Genetics XXXVII. 720 The occurrence of prototrophs, thus selected, from platings of thoroughly investigated auxotroph parents has been taken as prima facie evidence of crossing. 1958Heredity XII. 269 Bursts of white, prototrophic cells frequently arise from colonies of certain strains of red, adenine-requiring yeasts. The occurrence of prototrophs appears to result from back-mutation at the locus for adenine requirement. 1975J. B. Jenkins Genetics viii. 311 Prototrophs are cells that can grow on minimal medium.
Hence ˈprototrophy, the state of being a prototroph.
1952Genetics XXXVII. 720 The methionineless stock is, fortunately, so stable that back mutations to prototrophy are undetectable under the conditions of crossing experiments. 1974Nature 8 Feb. 387/1 E. coli strain H/r 30 R requiring arginine was used for measurement of mutation to prototrophy. 1975Ibid. 26 June 736/2 It was impossible to grow the population for long periods without reversion to prototrophy. |