ABSTRACT
Geneticists have become increasingly aware of the fact that genes move, that they change position within and between chromosomes, and that they thus alter their relationships to one another with important regulatory and structural consequences. The discovery of oncogenes, originally noted as transforming genes carried or activated by retroviruses, combined with a growing understanding of transcriptional control mechanisms, provided the basis for two molecular models that could explain how a translocation might induce malignancy. Both recombinational events occurring during immunocyte maturation have important implications with regard to the regulated expression of the immunoglobulin (Ig) genes. The activity of the c-myc gene as measured by the steady-state level of c-myc mRNA is elevated in a number of human non-Burkitt tumors. The Ig loci involved in the translocations have a very special property: they undergo site- or region-specific recombination that is critical for the development of antibody diversity.
