Blastopia is a LTR retrotransposon described in Drosophila melanogaster, the expression of this element plays a role in gene control (Frommer, Schuh and Jackle 1994). Blastopia belongs, along with other Ty3/Gypsy LTR retrotransposons, to Micropia/mdg3 clade (Malik and Eickbush 1999). The genomic structure of Blastopia is 5.4 Kb in size including LTRs of 277 nt. The internal region of this element displays a Primer Binding Site (PBS) complementary to tRNAPro, a single Open Reading Frame (ORF) coding for a gag-pol polyprotein, and a Polypurine Tract (PPT) adjacent to the 3´LTR (Frommer, Schuh and Jackle 1994).
Figure not to scale. If present, long terminal repeats (LTRs) have been highlighted in blue. Amino acid motifs noted with lines indicate the conserved residues in each protein domain, abbreviations below mean:
|DU or DUT=dUTPase
|TAV or IBMP=transactivator/viroplasmin or inclusion body matrix protein
|PBS=primer binding site
|ATF=aphid transmission factor
|VAP=virion associated protein