Dynamics of the hobo transposable element in transgenic lines of Drosophila melanogaster

The impact of the hobo transposable element in global reorganization of the Drosophila melanogaster genome has been investigated in transgenic lines g enerated by injection of hobo elements into the Hikone strain, which lacked them. In the present extensive survey, the chromosomal distribution of hob o insertion sites in the line 28 was found to be homogeneous and similar fo r all chromosomal arms, except 3L, when compared with other transgenic line s. However, some original features were observed in this line at the geneti c and chromosomal levels. Several hotspots of insertion sites were observed on the X, second and third chromosomes. Five sites with a high frequency o f hobo insertions were present on the 3L arm in most individuals tested, su ggesting the action of selection for hobo element in some sites. The presen ce of doublets or triplet was also observed, implying that hobo inserts can show local jumps or insertions in preferred regions. This local transposit ion occurred independently in 11 specific genomic regions in many individua ls and generations. The dynamics of this phenomenon were analysed across ge nerations. These results support the use of the hobo system as an important tool in fundamental and applied Drosophila genetics.