title: Structures of P transposable elements and their sites of insertion and excision in the Drosophila melanogaster genome.
abstract: We have isolated and characterized several members of the P transposable element family from a Drosophila melanogaster P strain. Large 2.9 kb elements are present as multiple highly conserved copies together with smaller (0.5-1.6 kb), heterogeneous elements. The complete DNA sequences of the 2.9 kb element and four small elements (previously isolated from hybrid-dysgenesis-induced mutations of the white locus) have been determined. Each small element appears to have arisen from the 2.9 kb element by a different internal deletion. P elements have 31 bp perfect inverse terminal repeats and upon insertion duplicate an 8 bp sequence found only once at the site of insertion. Three of the insertions into the white locus occurred at the same nucleotide, indicating a high degree of local site specificity for insertion. The basis of this specificity has been investigated by DNA sequence analysis of the sites where 18 P elements are found. A revertant of one of the white locus mutants has been found to result from precise excision of the P element, restoring the wild-type DNA sequence.
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000502:physiology; D005796:Genes; D009154:Mutation; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004251:DNA Transposable Elements