The Construction of Ring Chromosomes of Autosomal Heterochromatin in DROSOPHILA MELANOGASTER.

The synthesis of ring chromosomes consisting entirely of Drosophila autosomal heterochromatin is described. Our ability to obtain these heterochromatic ring chromosomes from irradiated oocytes is a logical prediction of and constitutes, therefore, a further proof for the translocation model of the origin of compound chromosomes. Additionally, the synthesis of these chromosomes provides us with potentially useful probes for the analysis of the function(s) of Drosophila heterochromatin.