Molecular resurrection of an extinct ancestral promoter for mouse L1.
The F-type subfamily of LINE-1 or L1 retroposons [for long interspersed (repetitive) element 1] was dispersed in the mouse genome several million years ago. This subfamily appears to be both transcriptionally and transpositionally inactive today and therefore may be considered evolutionarily extinct. We hypothesized that these F-type L1s are inactive because of the accumulation of mutations. To test this idea we used phylogenetic analysis to deduce the sequence of a transpositionally active ancestral F-type promoter, resurrected it by chemical synthesis, and showed that it has promoter activity. In contrast, F-type sequences isolated from the modern genome are inactive. This approach, in which the automated DNA synthesizer is used as a "time machine," should have broad application in testing models derived from evolutionary studies.
Adey
N B
NB
Department of Microbiology and Immunology, University of North Carolina at Chapel Hill 27599.
Tollefsbol
T O
TO
Sparks
A B
AB
Edgell
M H
MH
Hutchison
C A
CA
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics; D016384:Consensus Sequence; D004251:DNA Transposable Elements / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
D004251:DNA Transposable Elements; D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase