Practice question

All somatic cells derived from a single zygote through mitotic divisions inherit identical nuclear genome content, despite acquiring diverse phenotypes. This principle, genomic equivalence, explains how neurons, myocytes, and hepatocytes share same DNA sequence while expressing different gene subsets. Early nuclear transplantation experiments by Briggs, King, and Gurdon proved nuclei from differentiated cells could support complete embryonic development when placed in enucleated eggs. Exceptions like VDJ recombination in lymphocytes exist, but overall chromosomal complement remains equivalent. This concept revolutionized understanding of differentiation as regulation rather than gene loss.