Characterization of hobo element copy number and integrity in Brasilian populations of Drosophila melanogaster

We have determined the copy number and the presence of full-size hobo transposable elements in eight Brasilian strains of Drosophila melanogaster. Genomic DNA was digested with AvaII and XhoI restriction enzymes, respectively, and probed with a 963 bp sequence of the hobo element. Variable numbers of full-sized and defective elements were detected in all strains. The range of the copy number was 22.13 +/- 4.52. Blots showed the presence of a 2.6 kb fragment, corresponding to the complete element, in all strains exception of one and the 1.0 kb sequence, correponding to the Th1 and Th2 repressor elements. There was neither association among copy numbers of hobo elements and latitude nor the mean annual temperatures in the original geographical region of each strain.