Selection of the Genetic Basis for an Acquired Character

摘要: IN a letter under this title, Prof. C. H. Waddington1 has described an interesting selection experiment with Drosophila phenocopy of ‘crossveinless’. He demonstrated clearly that the phenocopic effect, at any rate in case, depends on individual genetic constitution as well shock treatment applied to pupae—a fact realized by Goldschmidt2 for phenocopies general, but not followed up Waddington done. Analogous results have been obtained laboratory using mutant ‘antennaless’3. Stocks homozygous gene show variable penetrance and expressivity ordinary culture media. Selection and/or close inbreeding individuals from such stocks can give rise lines showing whole range almost zero complete penetrance, representing effects ‘antennaless’ when combined different backgrounds4. The main difference between two experiments seems lie crossveinless life-history includes period highly abnormal conditions, whereas cycle is completed normal conditions. is, however, only one degree, situations would seem be essentially parallel.