PT  - JOURNAL ARTICLE
AU  - Moschetti, Roberta
AU  - Caggese, Corrado
AU  - Barsanti, Paolo
AU  - Caizzi, Ruggiero
TI  - Intra- and Interspecies Variation Among <em>Bari-1</em> Elements of the Melanogaster Species Group
DP  - 1998 Sep 01
TA  - Genetics
PG  - 239--250
VI  - 150
IP  - 1
4099  - http://www.genetics.org/content/150/1/239.short
4100  - http://www.genetics.org/content/150/1/239.full
SO  - Genetics1998 Sep 01; 150
AB  - We have investigated the distribution of sequences homologous to Bari-1, a Tc1-like transposable element first identified in Drosophila melanogaster, in 87 species of the Drosophila genus. We have also isolated and sequenced Bari-1 homologues from D. simulans, D. mauritiana, and D. sechellia, the species constituting with D. melanogaster the melanogaster complex, and from D. diplacantha and D. erecta, two phylogenetically more distant species of the melanogaster group. Within the melanogaster complex the Bari-1 elements are extremely similar to each other, showing nucleotide identity values of at least 99.3%. In contrast, Bari-1-like elements from D. diplacantha and D. erecta are on average only 70% similar to D. melanogaster Bari-1 and are usually defective due to nucleotide deletions and/or insertions in the ORFs encoding their transposases. In D. erecta the defective copies are all located in the chromocenter and on chromosome 4. Surprisingly, while D. melanogaster Bari-1 elements possess 26-bp inverted terminal repeats, their D. diplacantha and D. erecta homologues possess long inverted terminal repeats similar to the terminal structures observed in the S elements of D. melanogaster and in several other Tc1-like elements of different organisms. This finding, together with the nucleotide and amino acid identity level between D. diplacantha and D. erecta elements and Bari-1 of D. melanogaster, suggests a common evolutionary origin and a rapid diversification of the termini of these Drosophila Tc1-like elements.