Chimaeras of Drosophila melanogaster obtained by injection of haploid nuclei.

Since the observation by Bridges of a few mosaics containing haploid tissue in Drosophila, specimens supposedly haploid have rarely been found. A technique for the easy production of haploid animals or tissues could have important applications. We have now successfully designed such a technique by the production of chimaeras obtained by transplantation of haploid nuclei from a maternal effect mutant that produces haploid embryos. We have used this technique to test the proposal of Jack and Judd that the zeste locus of Drosophila melanogaster cannot repress the activity of unpaired alleles at the white locus.