Plasticity of the differentiated state

HM Blau, GK Pavlath, EC Hardeman, CP Chiu… - Science, 1985 - science.org
HM Blau, GK Pavlath, EC Hardeman, CP Chiu, L Silberstein, SG Webster, SC Miller…
Science, 1985science.org
Heterokaryons provide a model system in which to examine how tissue-specific phenotypes
arise and are maintained. When muscle cells are fused with nonmuscle cells, muscle gene
expression is activated in the nonmuscle cell type. Gene expression was studied either at a
single cell level with monoclonal antibodies or in mass cultures at a biochemical and
molecular level. In all of the nonmuscle cell types tested, including representatives of
different embryonic lineages, phenotypes, and developmental stages, muscle gene …
Heterokaryons provide a model system in which to examine how tissue-specific phenotypes arise and are maintained. When muscle cells are fused with nonmuscle cells, muscle gene expression is activated in the nonmuscle cell type. Gene expression was studied either at a single cell level with monoclonal antibodies or in mass cultures at a biochemical and molecular level. In all of the nonmuscle cell types tested, including representatives of different embryonic lineages, phenotypes, and developmental stages, muscle gene expression was induced. Differences among cell types in the kinetics, frequency, and gene dosage requirements for gene expression provide clues to the underlying regulatory mechanisms. These results show that the expression of genes in the nuclei of differentiated cells is remarkably plastic and susceptible to modulation by the cytoplasm. The isolation of the genes encoding the tissue-specific trans-acting regulators responsible for muscle gene activation should now be possible.
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