LETHAL CHROMOSOMAL DELETIONS IN THE MOUSE, A MODEL SYSTEM FOR THE STUDY OF DEVELOPMENT AND REGULATION OF POSTNATAL GENE-EXPRESSION

Mechanisms involved in the regulation of development and its genetic control are receiving ever-increasing attention in studies of mammalian developmental genetics. The potential success of such studies is strongly enhanced by the availability of suitable systems of analysis. Such a system was identified in a series of radiation-induced chromosomal deletions at and around the albino (c) locus of the mouse associated with cell type-specific effects on liver differentiation. Their detailed study has aided the analysis of possible mechanisms of cell type-specific gene expression. As summarized in this review, the experimental results strongly suggest that specific trans-acting developmental regulatory genes are concerned with the differentiation of hormone-inducible expression of a cluster of hepatocyte specific structural genes mapping in different parts of the genome.