Rapid amplification of a retrotransposon subfamily is evolving the mouse genome

Nat Genet. 1998 Nov;20(3):288-90. doi: 10.1038/3104.


Retrotransposition affects genome structure by increasing repetition and producing insertional mutations. Dispersion of the retrotransposon L1 throughout mammalian genomes suggests that L1 activity might be an important evolutionary force. Here we report that L1 retrotransposition contributes to rapid genome evolution in the mouse, because a number of L1 sequences from the T(F) subfamily are retrotransposition competent. We show that the T(F) subfamily is large, young and expanding, containing approximately 4,800 full-length members in strain 129. Eleven randomly isolated, full-length T(F) elements averaged 99.8% sequence identity to each other, and seven of these retrotransposed in cultured cells. Thus, we estimate that the mouse genome contains approximately 3,000 active T(F) elements, 75 times the estimated number of active human L1s. Moreover, as T(F) elements are polymorphic among closely related mice, they have retrotransposed recently, implying rapid amplification of the subfamily to yield genomes with different patterns of interspersed repetition. Our data show that mice and humans differ considerably in the number of active L1s, and probably differ in the contribution of retrotransposition to ongoing sequence evolution.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 5' Untranslated Regions
  • Animals
  • Evolution, Molecular*
  • Gene Amplification*
  • Genome*
  • Humans
  • Mice
  • Molecular Sequence Data
  • Mutation
  • Polymorphism, Genetic
  • Retroelements
  • Species Specificity


  • 5' Untranslated Regions
  • Retroelements

Associated data

  • GENBANK/AF081104
  • GENBANK/AF081105
  • GENBANK/AF081106
  • GENBANK/AF081107
  • GENBANK/AF081108
  • GENBANK/AF081109
  • GENBANK/AF081110
  • GENBANK/AF081111
  • GENBANK/AF081112
  • GENBANK/AF081113
  • GENBANK/AF081114