INTERACTION SYSTEMS BETWEEN HETEROCHROMATIN AND EUCHROMATIN IN DROSOPHILA-MELANOGASTER

The constitutive heterochromatin is still one of the major unsolved pr oblems in genetics. In Drosophila melanogaster three genetic systems i nvolving specific interactions between heterochromatic and euchromatic genetic elements are known: the Segregation Distortion, the crystal-S tellate and the abo-ABO systems. The genetic and molecular analysis of each system will allow the identification of all the components and t he elucidation of the mechanisms underlying their interactions. The re sults of this analysis should provide insights into the biological sig nificance of heterochromatin and into the evolutionary forces that res ult in the maintainance and stability of this enigmatic genetic materi al.