S elements: a family of Tc1-like transposons in the genome of Drosophila melanogaster.
The S elements form a diverse family of long-inverted-repeat transposons within the genome of Drosophila melanogaster. These elements vary in size and sequence, the longest consisting of 1736 bp with 234-bp inverted terminal repeats. The longest open reading frame in an intact S element could encode a 345-amino acid polypeptide. This polypeptide is homologous to the transposases of the mariner-Tc1 superfamily of transposable elements. S elements are ubiquitous in D. melanogaster populations and also appear to be present in the genomes of two sibling species; however, they seem to be absent from 17 other Drosophila species that were examined. Within D. melanogaster strains, there are, on average, 37.4 cytologically detectable S elements per diploid genome. These elements are scattered throughout the chromosomes, but several sites in both the euchromatin and beta heterochromatin are consistently occupied. The discovery of an S-element-insertion mutation and a reversion of this mutation indicates that S elements are at least occasionally mobile in the D. melanogaster genome. These elements seem to insert at an AT dinucleotide within a short palindrome and apparently duplicate that dinucleotide upon insertion.
Merriman
P J
PJ
Department of Genetics and Cell Biology, University of Minnesota, St. Paul 55108-1095, USA.
Grimes
C D
CD
Ambroziak
J
J
Hackett
D A
DA
Skinner
P
P
Simmons
M J
MJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D016678:Genome; D008297:Male; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid
D004251:DNA Transposable Elements; D004247:DNA