title: Dictyostelium transposable element DIRS-1 preferentially inserts into DIRS-1 sequences.
abstract: Sequence analysis of genomic clones containing the intact Dictyostelium transposable element DIRS-1 reveals that in five of six cases DIRS-1 has inserted into other DIRS-1 sequences. The nucleotide sequences just beyond the endpoints of the terminal repeats of five different genomic clones can be aligned with different regions of the internal nucleotide sequence of DIRS-1. In the three genomic clones which contain flanking sequences on both sides of the element, both flanking sequences are homologous with DIRS-1. In one of these clones, both extended flanking sequences represent the full 4.1-kilobase EcoRI fragment of DIRS-1, which has been interrupted by the insertion of an intact DIRS-1 element. There is no duplication or deletion (except possibly 1 base) of the DIRS-1 sequence upon insertion of a second DIRS-1 transposon. DIRS-1-into-DIRS-1 insertions can occur in either a colinear or inverted orientation with respect to the target sequence; the target sequence need not be an intact DIRS-1 element. We also describe a cDNA clone which could be derived by transcription of a sequence that resulted from a DIRS-1-into-DIRS-1 insertion and discuss its significance concerning the function of the heat-shock promoters found in the terminal repeats of DIRS-1 and in other DIRS-1-related sequences.
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000032:analysis; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004251:DNA Transposable Elements; D004023:Dictyostelium / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D004251:DNA Transposable Elements; D004247:DNA; D004262:DNA Restriction Enzymes