Alternative titles; symbols
Shapero et al. (1994) noted that the expression of many liver-specific genes is extinguished when cultured hepatoma cells are fused with fibroblasts. Extinguished liver genes can be reexpressed in hybrid segregants that have lost chromosomes from the fibroblast parent, suggesting that extinction is an active process mediated by trans-acting regulatory factors. Two extinguisher loci had been reported previously: one, TSE1, on human chromosome 17 (188830), and a second, TSE2, on human chromosome 2 (601136). Shapero et al. (1994) transferred human chromosomes with a selectable marker into rat hepatoma cells by microcell fusion and studied the expression of liver-specific mRNAs in nearly 200 human/rat microcell hybrid clones, using the transcript from rat PEPCK (614168) as a detectable molecular marker. PEPCK mRNA synthesis was extinguished in 12 of these hybrid clones. The authors noted that some of these hybrids contained human TSE1, but others contained a novel extinguishing function that mapped to human chromosome 14. The identity and mechanism of the locus, designated TSE3 by them, remained to be defined.
Shapero, M. H., Langston, A. A., Fournier, R. E. K. Tissue-specific extinguisher loci in the human genome: a screening study based on random marking and transfer of human chromosomes. Somat. Cell Molec. Genet. 20: 215-231, 1994. [PubMed: 7940022] [Full Text: https://doi.org/10.1007/BF02254761]