title: The molecular basis of I-R hybrid dysgenesis in Drosophila melanogaster: identification, cloning, and properties of the I factor.
abstract: We have analyzed two mutations of the white-eye gene, which arose in flies subject to I-R hybrid dysgenesis. These mutations are associated with insertions of apparently identical 5.4 kb sequences, which we have cloned. We believe that these insertions are copies of the I factor controlling I-R hybrid dysgenesis. The I factor is not a member of the copia-like or fold-back classes of transposable elements and has no sequence homology with the P factor that controls P-M dysgenesis. All strains of D. melanogaster contain I-factor sequences. Those present in reactive strains must represent inactive I elements. I elements have a remarkably similar sequence organization in all reactive strains and are located in peri-centromeric regions. Inducer strains appear to contain both I elements, located in peri-centromeric regions, and 10-15 copies of the complete I factor at sites on the chromosome arms.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002875:Chromosomes / Q000648:ultrastructure; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D004247:DNA / Q000302:isolation & purification; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D008297:Male; D009154:Mutation; D009693:Nucleic Acid Hybridization; D010957:Plasmids
chemical_list: D004251:DNA Transposable Elements; D004247:DNA; D004262:DNA Restriction Enzymes