title: Conserved motifs and dynamic aspects of the terminal inverted repeat organization within Bari-like transposons.
abstract: In this work the structural variations of Terminal Inverted Repeats (TIR) of Bari like transposons in Drosophila species has been studied. The aim is to try and assess the relevance of different variants in the evolutionary distribution of Bari elements. Bari is a member of the widespread Tc1 superfamily of transposable elements that has colonized most species of the Drosophila genus. We previously reported the structure of two related elements that differ in their TIR organization: Bari1 harbouring 26-bp TIR (short TIRs) and Bari2 with about 250-bp TIR (long TIIR). While elements with short TIRs are complete and potentially autonomous, long ones are invariably composed of defective copies. The results show that in D. pseudobscura, D. persimilis and D. mojavensis, there is a third class of Bari elements, Bari3, that exhibit a long TIR structure and are not defective. Phylogenetic relationships among reconstructed transposases are consistent with the three subfamilies sharing a common origin. However, the final TIR organization into long or short structure is not related by descent but appears to be lineage-specific. Furthermore, we show that, independently of origin and organization, within the 250-bp terminal sequences there are three regions that are conserved in both sequence and position suggesting they are under functional constraint.
authors.affiliation: Department of Genetics and Microbiology, University of Bari, Via Amendola 165/A, 70126 Bari, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Moschetti
authors.forename: Sarantis
authors.initials: S
authors.lastname: Chlamydas
authors.forename: Renè Massimiliano
authors.initials: RM
authors.lastname: Marsano
authors.forename: Ruggiero
authors.initials: R
authors.lastname: Caizzi
mesh_terms: D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D017124:Conserved Sequence; D004251:DNA Transposable Elements / Q000235:genetics* / Q000502:physiology; D004330:Drosophila / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation; D016678:Genome; D008969:Molecular Sequence Data; D010802:Phylogeny; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D020079:Terminal Repeat Sequences / Q000235:genetics* / Q000502:physiology
chemical_list: D004251:DNA Transposable Elements