Synthesis of ribonucleic acid by the X-chromosomes of Drosophila melanogaster and the problem of dosage compensation

Investigations of the expression of various sex-linked genes in Drosophila have shown that for most of them their phenotypic manifestation is identical in male and female. Stern, Muller and later Muller et al. by use of mutations such as bobbed and apricot in various doses showed that the identity and equality of genie expression between the two sexes are not associated, a priori, with the development of sex, but rather involves a system of genes, plus and minus modifiers, which regardless of sex tends to repress the action of extra doses of sex-linked genes. Muller proposed the name 'dosage compensation' for this effect and concluded that for each sex-linked gene there is a set of 'compensator genes'