Abstract
TYROSINE aminotransferase (TAT) is not inducible by corticosteroid hormones in heterokaryocytes and hybrid cells resulting from the fusion of rat hepatoma cells with mouse fibroblasts1,2. Fusion of rat hepatoma cells with human fibroblasts also results in the loss of TAT inducibility, but because of the unidirectional loss of human chromosomes in the resulting hybrid cells3, inducibility of TAT is re-expressed in some clones4. The suppression or modulation of the expression of TAT inducibility in such hybrid clones seems to be related to presence of the human X chromosome4. Since rat–human hybrid clones in which TAT inducibility is suppressed have the same corticosteroid receptor activity as the rat parental cells4, the absence of inducibility cannot be ascribed to a decrease in corticosteroid receptor activity.
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CROCE, C., KOPROWSKI, H. & LITWACK, G. Regulation of the corticosteroid inducibility of tyrosine aminotransferase in interspecific hybrid cells. Nature 249, 839–841 (1974). https://doi.org/10.1038/249839a0
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DOI: https://doi.org/10.1038/249839a0
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