Replicating and cycling stores of information perpetuate life

Life is perpetuated through a single-cell bottleneck between generations in many organisms. Here, I highlight that this cell holds information in two distinct forms: in the linear DNA sequence that is replicated during cell divisions, and in the three-dimensional arrangement of molecules that can change during development but that is recreated at the start of each generation. These two interdependent stores of information - one replicating with each cell division and the other cycling with a period of one generation - coevolve while perpetuating an organism. Unlike the genome, the cycling arrangement of molecules, which could include RNAs, proteins, sugars, lipids, etc., is not well understood. Because this arrangement and the genome are together transmitted from one generation to the next, analysis of both is necessary to understand evolution, origins of inherited diseases, and consequences of genome engineering. Recent developments suggest that tools are in place to examine how all the information to build an organism is encoded within a single cell, and how this cell code is reproduced in every generation.