Phylogenetic analysis reveals that the members of the S-element family of D. melanogaster can be grouped into at least two genetically differentiated clusters.
The S-element transposable elements form a diverse family of long-inverted repeat transposons, varying in size and sequence. The longest is 1736bp with 234bp inverted repeats. The 345-amino acid polypeptide is homologous to transposases of the Mariner-Tc1 superfamily. S-elements are ubiquitous in D.melanogaster and relatives are present in the two sibling species D.mauritiana and D.simulans, but are absent from 17 other species examined. There are on average 37.4 copies per diploid genome. They insert at an AT dinucleotide within a short palindrome and apparently duplicate the dinucleotide upon insertion.
Phylogenetic analysis reveals that the members of the S-element family of D. melanogaster can be grouped into at least two genetically differentiated clusters.
The S-element transposable elements form a diverse family of long-inverted repeat transposons, varying in size and sequence. The longest is 1736bp with 234bp inverted repeats. The 345-amino acid polypeptide is homologous to transposases of the Mariner-Tc1 superfamily. S-elements are ubiquitous in D.melanogaster and relatives are present in the two sibling species D.mauritiana and D.simulans, but are absent from 17 other species examined. There are on average 37.4 copies per diploid genome. They insert at an AT dinucleotide within a short palindrome and apparently duplicate the dinucleotide upon insertion.
Copies of the S-element are present within the chromocentre and euchromatic chromosome arms.