Shared sequence variants of Mus spretus LINE-1 elements tracing dispersal to within the last 1 million years.
LINE-1 repetitive sequences contain a record of an evolving population of transposons within the mammalian genome. Of the 100,000 copies of LINE-1 sequences per genome there are many shared sequence variants representing changes occurring within the propagating LINE-1 elements themselves, rather than changes that occur during retrotransposition or after an element inserts in the genome. These shared sequence variants define families of LINE-1 elements which have spread within specific periods of time. We have been interested in studying events in LINE-1 evolution since the speciation of Mus spretus and Mus domesticus approximately 3 million years (Myr) ago. To do this, we have collected LINE-1 sequences that have shared sequence variants specific to M. spretus. The sampled LINE-1 elements were sequenced at their extreme 3' ends, where the density of sequence variants is highest. The new sequences define six new M. spretus-specific sequence variants. Of these, we have found one that could be used to screen for LINE-1 elements arising in the last 1 Myr, which we argue is a critical sample for understanding the dynamics of LINE-1 propagation.
Casavant
N C
NC
Department of Biochemistry, University of Texas Health Science Center at San Antonio 78284-7760.
Hardies
S C
SC
D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements; D014644:Genetic Variation; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D009115:Muridae / Q000235:genetics*; D010802:Phylogeny; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D013995:Time
D004251:DNA Transposable Elements