GF Elements Retrotranpose in Human TK− 143B Cells and HeLa Cells
| Name | Strain Clone #) | Retrotransposition frequency | |||
| 143B cells | HeLa cells | ||||
| with CMV | w/o CMV | with CMV | w/o CMV | ||
| GF13 | 120/Ola (19–37) | 1 | <1 | ||
| C57Bl/2J (14–25) | 0 | <1 | |||
| 129/Ola (19) | 12 | 26 | |||
| C57Bl/6J (15) | 3 | 6 | |||
| C57Bl/6J (14) | 6 | 4 | |||
| 129/Sv+C/+P(22) | 0 | nk | |||
| GF21 | C57Bl/6J (18–17) | 1482 | 720 | ||
| C57Bl/6J (35–10) | 1418 | 1683 | |||
| C57Bl/6J (18–36) | 1150 | 1523 | |||
| C57Bl/6J (35–37) | 727 | 2942 | |||
| C57Bl/6J (35–92) | 394 | 2240 | |||
| SJL/J (86–39) | 380 | 816 | |||
| GF27 | C57Bl/6J (55–62) | 0 | 0 | ||
| C57Bl/6J (55–48) | 0 | 2 | |||
| GF62 | LP/J (92–59) | 35 | 1 | ||
| LP/J (92–45) | 65 | 69 | |||
| A101 | 332 | 792 | |||
| A102 | 682 | 3767 | |||
| TF9.1 | 557 | 1173 | |||
| L1spa | 121 | 352 | |||
| L1spa ORF2 D709Y | 0 | 0 | |||
| L1RP | 1884 | ∼7300 | |||
| JM105 ORF2 D709Y | 0 | 0 | |||
[i] Shown for each construct is the average retrotransposition frequency (G418R foci/106 hygromycin-resistant cells) for at least three independent transfections. Cloned GF constructs were obtained by PCR amplification of DNA from a single individual from several different laboratory strains of mouse. Clonal differences in activity may be due to PCR errors. DNA from strains 129/Ola and 129/Sv+C/+P was obtained from pluripotent embryonic stem cells (ATCC CRL-1821 (ES-E14TG2a) and ATCC CRL-1934 (ES-D3), respectively). The TF subfamily member, TF9, is described inDeBerardinis et al. (1998). L1RP, a human L1 discovered as a de novo insertion in the RP2 gene of a retinitis pigmentosa patient, is the most active L1 that has so far been tested in the cell culture assay (Kimberland et al. 1999). As negative controls, we used reverse-transcriptase defective alleles of the TF element, L1spa (ORF2 D709Y), and the human element, JM105 (ORF2 D709Y) (Moran et al. 1996; Naas et al. 1998).