High frequency retrotransposition in cultured mammalian cells

Cell. 1996 Nov 29;87(5):917-27. doi: 10.1016/s0092-8674(00)81998-4.


We previously isolated two human L1 elements (L1.2 and LRE2) as the progenitors of disease-producing insertions. Here, we show these elements can actively retrotranspose in cultured mammalian cells. When stably expressed from an episome in HeLa cells, both elements retrotransposed into a variety of chromosomal locations at a high frequency. The retrotransposed products resembled endogenous L1 insertions, since they were variably 5' truncated, ended in poly(A) tracts, and were flanked by target-site duplications or short deletions. Point mutations in conserved domains of the L1.2-encoded proteins reduced retrotransposition by 100- to 1000-fold. Remarkably, L1.2 also retrotransposed in a mouse cell line, suggesting a potential role for L1-based vectors in random insertional mutagenesis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Chromosomes / genetics
  • Conserved Sequence
  • Cysteine / genetics
  • DNA Mutational Analysis
  • Fibroblasts / physiology
  • Genome
  • HeLa Cells / physiology
  • Humans
  • Mammals
  • Mice
  • Mutagenesis / genetics
  • Open Reading Frames / genetics
  • Promoter Regions, Genetic / genetics
  • RNA, Messenger / genetics
  • Retroelements / genetics*
  • Time Factors


  • RNA, Messenger
  • Retroelements
  • Cysteine