The theory that all cells of an organism contain an equivalent complement of genetic information. Genomic equivalence has been confirmed for most cells, but exceptions occur in some animal cells where loss, gain, or rearrangement of nuclear DNA has been observed. Examples of such exceptions include chromatin diminution (q.v.) in somatic cells of some nematodes, selective amplification of rRNA genes in Xenopus oocytes, and DNA excision and rearrangement during mammalian lymphocyte maturation that result in the generation of antibody diversity. See gene amplification, immunoglobulin genes.
Subjects: Genetics and Genomics.