Abundance and chromosomal distribution of six Drosophila buzzatii transposons: BuT1, BuT2, BuT3, BuT4, BuT5, and BuT6

The abundance and chromosomal distribution of six class-II transposable elements (TEs) of Drosophila buzzatii have been analyzed by Southern blotting and in situ hybridization. These six transposons had been previously found at the breakpoints of inversions 2j and 2q ⁷ of D. buzzatii. These two polymorphic inversions were generated by an ectopic recombination event between two copies of Galileo, a Foldback element. The four breakpoints became hotspots for TE insertions after the generation of the inversion and the transposons analyzed in this work are considered to be secondary invaders of these regions. Insertions of the six transposons are present in the euchromatin but show an increased density in the pericentromeric euchromatin–heterochromatin transition region and the dot chromosome. They are also more abundant in the inverted segments of chromosome 2 rearrangements. We further observed that the accumulation of TE insertions varies between elements and is correlated between dot, proximal regions, and inverted segments. These observations fully agree with previous data in Drosophila melanogaster and support recombination rate as the chief force explaining the chromosomal distribution of TEs.Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users.Sequence data from this article have been deposited in the EMBL/GenBank Data Libraries under accession number DQ402469.