Quantitative Measurement of Heritability in the Pre-RNA World

TL;DR

This study demonstrates that cellular hysteresis, specifically thermal hysteresis in cell size, correlates with heritability and stability in cell division, suggesting self-organized systems played a key role in early and modern heredity.

Contribution

It establishes a quantitative link between hysteresis phenomena and heritability, highlighting the importance of self-organized complex systems in heredity across evolutionary history.

Findings

Thermal hysteresis correlates with cell line stability.

Hysteresis indicates equal partitioning during cell division.

Self-organized systems contribute to heredity in mammalian cells.

Abstract

Long ago, life obtained nucleotides in the course of evolution and became a vehicle for them. Before assembly with nucleotides, in the pre-RNA era, what system dominated heredity? What was the subject of survival competition? Is it still a subject of competition? Self-organized complex systems are hypothesized to be a primary factor of the origin of life and to dominate heritability, mediating the partitioning of an equal distribution of structures and molecules at cell division. The degree of strength of self-organization would correlate with heritability; self-organization is known to be a physical basis of hysteresis phenomena, and the degree of hysteresis is quantifiable. However, there is no argument corroborating the relationship between heritability and hysteresis. Here, we show that the degree of cellular hysteresis indicates its heritability and daughter equivalence at cell division. We found a correlation between thermal hysteresis in cell size and heritability, which quantified cell line generation stability, suggesting that the self-organized complex system is a subject of survival competition, comparable to nucleotides. Furthermore, in single-cell-resolution observations, we found that thermal hysteresis in cell size indicates equivalent partitioning in future cell division. Our results demonstrate that self-organized complex systems contribute to heredity and are still important in mammalian cells. Predicting the cell line generational stability required for the industrial production of therapeutic biologics is useful. Discovering ancient and hidden heredity systems enables us to study our own origin, to predict cell features and to manage them in the bio-economy.