A TELOMERE-LIKE SATELLITE (GGGTCAT)(N) COMPRISES 4-PERCENT OF GENOMIC DNA OF DROSOPHILA-HYDEI AND IS LOCATED MAINLY IN CENTROMERIC HETEROCHROMATIN OF ALL LARGE ACROCENTRIC AUTOSOMES

We describe the isolation and analysis of a G+C-rich telomere-like (GGGTCAT)(n) satellite of Drosophila hydei. GGGTCAT-specific clones were obtained by a combination of restriction enzyme digestion and fractionation of D. hydei DNA by pulsed-field gel electrophoresis (PFGE). High-molecular-weight DNA (> 50 kb) was recovered from gels, sheared by sonication and cloned into the pBS plasmid vector. The results of PFCE analysis, quantitative dot blot measurements and fluorescence in situ hybridization (FISH) on metaphase chromosomes show that the tandemly arranged GGGTCAT sequences comprise 4% of genomic DNA and are organized as megabase-sized clusters in the pericentric region of all large acrocentric autosomes. A telomere-related function is rather unlikely, because the chromosomal ends of D. hydei seem to be free of GGGTCAT repeats and several other species of Drosophila do not contain any cross-hybridizing sequences at all.