Nested insertions of short mobile sequences in Drosophila P elements

摘要: A potentially full-sized P element isolated from the genome of Drosophila ambigua by polymerase chain reaction amplification was completely sequenced. It has a length 3329 bp and termini are formed 33 inverted repeats. Sequence comparisons show that it can be classified as member T-type subfamily. The translational reading frames all four exons interrupted stop codons frameshift mutations. At 3′ end exon 3 687 insertion sequence (IS-amb-P) is found also occurs in form dispersed copies (IS-amb) D. ambigua. interspecific level shows homology to mobile sequences other species obscura group. Although variable length, these IS elements characterized conserved sections without coding function 14 repeats, one at terminal, subterminal position. In situ hybridization revealed restricted only two euchromatic sites on chromosome E. This situation resembles guanche subobscura where homologs clustered single site E section corresponding carries an element. gene sik-hom, which located 5′ side cluster homologs, used marker examine whether homologous. results suggest nested insertions into must have occurred independently different lineages.