Three-dimensional organization of telomeres in nuclei of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis> salivary glands

3D-FISH method was employed to investigate the telomere topology in polytene nuclei of salivary glands in Drosophila melanogaster. The majority of telomeres in polytene nuclei of salivary glands in Drosophila strain y^2-717 is localized in the nuclear central area and have no contacts with nuclear membrane. In the females ectopic contacts between telomeres occur in frequency 25% higher than in males. HeT-A DNA in y^2-717alk3-2 strain, which is a derivative of the y^2-717 stain carrying an inversion between 1B and 13C bands, is found in the region 13 of X chromosome. The frequency of ectopic contacts of telomeres in y^2-717alk3-2 males is 10% higher than in the y^2-717 strain. The number of ectopic contacts can be differ significantly in independent experiments, possibly indicating the role of random factors in the contact formation.