Stable microsatellite length but frequent allele loss in SV40-immortalized Werner syndrome and control cell lines
- Univ. of Washington, Seattle, WA (United States)
We have determined the mitotic stability of microsatellite alleles and allele lengths in SV40-immortalized Werner syndrome (WS) and control cell lines. The impetus for this work was presence of a mutator phenotype in WS cells and cell lines and the association between a DNA mismatch repair deficit and microsatellite length instability in a heritable human tumor syndrome. Thus the identification of microsatellite length instability in WS cells might provide a clue to the primary biochemical defect in WS and a partial explanation for the mutator phenotype and the elevated cancer risk of WS patients. Five microsatellite loci (D2S123, D10S197, D10S141, D8S255, and D8S87) were PCR genotyped in 88 independent clones derived from four SV40-immortalized fibroblast cell lines (two WS lines: WV1 and PSV811; and two control lines: GM637 and GM639). Stable allele lengths were transmitted from cell line to clones in every case. WS cell line WV1 contained a preexisting faint third D2S123 allele which was transmitted with the other two D2S123 alleles to a majority of WV1 clones. In contrast, microsatellite allele loss was common: complete absence of one of two alleles was seen in 30% of control and in 3% of WS clones. Complete allele loss likely results from a clonal population being derived from a cell lacking a microsatellite allele. Altered relative band intensities in clones compared to parental lines were very common in both WS and control backgrounds (40% of all clones). This suggests that allele loss is common and continues upon post-cloning cell culture. These allele losses are likely to be a consequence of the genetic instability that accompanies SV40 immortalization. These results indicate that SV40-immortalized cell lines are genetically heterogeneous, and that the genotypes of individual clones may incompletely represent the genomes of the primary cells from which they were derived.
- OSTI ID:
- 133477
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0205
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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