Molecular paleontology of transposable elements in the Drosophila melanogaster genome.
We report here a superfamily of "cut and paste" DNA transposons called Transib. These transposons populate the Drosophila melanogaster and Anopheles gambiae genomes, use a transposase that is not similar to any known proteins, and are characterized by 5-bp target site duplications. We found that the fly genome, which was thought to be colonized by the P element <100 years ago, harbors approximately 5 million year (Myr)-old fossils of ProtoP, an ancient ancestor of the P element. We also show that Hoppel, a previously reported transposable element (TE), is a nonautonomous derivate of ProtoP. We found that the "rolling-circle" Helitron transposons identified previously in plants and worms populate also insect genomes. Our results indicate that Helitrons were horizontally transferred into the fly or/and mosquito genomes. We have also identified a most abundant TE in the fly genome, DNAREP1_DM, which is an approximately 10-Myr-old footprint of a Penelope-like retrotransposon. We estimated that TEs are three times more abundant than reported previously, making up approximately 22% of the whole genome. The chromosomal and age distributions of TEs in D. melanogaster are very similar to those in Arabidopsis thaliana. Both genomes contain only relatively young TEs (<20 Myr old), constituting a main component of paracentromeric regions.
Genetic Information Research Institute, 2081 Landings Drive, Mountain View, CA 94043, USA. vladimir@ulam.girinst.org
Vladimir V
VV
Kapitonov
Jerzy
J
Jurka
D000595:Amino Acid Sequence; D000818:Animals; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D016678:Genome; D008969:Molecular Sequence Data; D010163:Paleontology; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
D004251:DNA Transposable Elements