Generalisation of the Central Dogma

• Generalisation of the Central Dogma is defined as a framework where nucleic acids transmit heritable information while proteins execute functional roles, extending from molecules to social systems.
• It employs evolutionary dynamics and symmetry-breaking mechanisms to explain the emergence of specialized roles, such as germ-soma differentiation and eusocial structures.
• This unified perspective has practical implications for understanding evolvability, regulatory architecture, and the organization of complex biological systems.

The generalisation of the Central Dogma expands the classical view of molecular information flow—DNA to RNA to protein—into a cross-hierarchical organizational and evolutionary principle. This generalisation posits the Central Dogma not simply as a unidirectional molecular constraint, but as a division of labour between the transmission and expression of information. The transmitter (nucleic acids) perpetuates heritable information across generations, while the expressor (protein) enacts this information to facilitate the transmitter’s function without perpetuating itself. This framework applies beyond molecular biology, offering a unified lens to interpret information management at multiple biological levels, from molecular systems to multicellular organisms and social groups, and is grounded in formal evolutionary dynamics.

1. Conceptual Generalisation of the Central Dogma

The classical Central Dogma asserts that information flows irreversibly from nucleic acids (DNA/RNA) to proteins, with no feedback of information from protein to nucleic acid. The generalised view reframes this as a division of labour between transmitter and expressor components. In this paradigm:

• Transmitter (nucleic acids): Maintains and propagates heritable, sequence-encoded information over generations.
• Expressor (protein): Executes the catalytic and functional roles dictated by the encoded information, but does not itself serve as a persistent informational repository.

This informational partition is not limited to molecular biology; analogous structures exist wherever a separation between storage and enactment functions occurs. Temporarily reversible flows (e.g., protein conformation templating, prion propagation) are not excluded, so long as persistent informational lineages conflicting with this separation are not maintained (Takeuchi et al., 6 Aug 2025).

2. Cross-Hierarchical Organization and Analogies

The generalized Central Dogma principle extends well beyond the molecular scale. At various hierarchical levels, the transmitter–expressor relationship recurs:

• Eusocial insects: Queens act as transmitters, producing eggs and transmitting genetic information; sterile workers (expressors) enact colony functions (foraging, defense) but do not contribute to heredity.
• Multicellular eukaryotes: Germline cells (transmitters) give rise to gametes; somatic cells (expressors) differentiate, perform functions, and do not contribute to genetic continuity.
• Ciliates: The micronucleus (transmitter) retains heritable information; the macronucleus (expressor) undergoes irreversible genomic rearrangement to drive cell function.
• Bacterial systems (e.g., Streptomyces coelicolor): Wild-type fast-replicators act as transmitters, while mutants with genome truncations (expressors) specialize in secondary metabolite production without contributing to reproduction (Takeuchi et al., 6 Aug 2025).

This division is a recurrent solution to evolutionary challenges across biological systems, supporting a structural homology in the management of genetic and phenotypic information.

Biological Scale	Transmitter	Expressor
Molecular	Nucleic acids	Proteins
Cell lineages	Germline	Soma
Social insects	Queens	Workers
Ciliates	Micronucleus	Macronucleus

3. Evolutionary Dynamics and Symmetry Breaking

The generalization posits that the Central Dogma arises as an outcome of evolutionary conflicts between different levels of selection, formalized in a symmetry-breaking mathematical model:

• Early replicators combined information storage and catalysis, yielding a trade-off between accurate template function (for heredity) and catalytic efficiency (for function).
• Selection operates both at the molecular (within-cell) and collective (between-cell) levels:
  • Within-cell: Molecules evade the cost of catalysis to maximize their own replication.
  • Between-cell: Cells/protocells benefit from increased overall catalytic activity, even at the expense of individual molecules.

A minimal asymmetry (e.g., via stochastic fluctuation) leads to positive feedback: if molecules of type P become more catalytic than type Q, then P replicators experience reduced copying fidelity, reinforcing differentiation:

$$\langle \kappa^{P} \rangle > \langle \kappa^{Q} \rangle \implies \langle \omega^{P} \rangle < \langle \omega^{Q} \rangle$$

The system’s fitness is then captured by:

$\lambda = \omega^P + \omega^Q$

with $\omega^P$ and $\omega^Q$ the respective replication rates in the P and Q molecular states.

Through Price-like equations (as in Eqs. [5]–[7] of (Takeuchi et al., 6 Aug 2025)), these dynamics ultimately produce a division wherein one species stabilizes as the transmitter (replicating faithfully and rarely engaging in catalysis) and the other as the expressor (specializing in catalysis with compromised replication efficiency).

4. Functional and Regulatory Implications

The division of labour yields several broad evolutionary advantages:

• Unifying Principle: The transmitter–expressor dichotomy is manifest at various organization levels, offering a cross-hierarchical theory for major transitions, including the origin of multicellularity and social cooperation.
• Evolvability: Numerical asymmetry (many expressors, few transmitters) amplifies phenotypic effects of genetic changes, accelerating adaptive responses.
• Separation of Timescales: Information is insulated in transmitters (which replicate more slowly), whereas expressors can be produced in abundance and replaced rapidly, facilitating regulatory adaptability.
• Enhanced Regulation: Partitioning information storage and functional delivery enables nuanced, environmentally responsive regulatory control.

Such dynamics can be represented in a formal mapping between roles and dynamical contribution:

$$\text{Total fitness} = f(\text{Transmission}, \text{Expression})$$

Regulatory architectures emerge allowing cells, multicellular organisms, and colonies to modulate functional output independently from information perpetuation.

5. Informational Relationship and Irreversibility

The generalisation shifts the explanatory burden from molecular chemistry to evolutionary logic: irreversibility in the flow of information (from transmitter to expressor but not back) is maintained not for chemical reasons alone, but because evolutionary stability requires insulation of heritable information from functional noise and damage. Protein–to–protein propagation (such as in prion transmission) is allowable only if it does not produce cross-generational informational persistence that would blur the transmitter–expressor boundary.

Biological systems thus embody design-level separation between persistent information archives and transient functional execution—a logic found in a variety of complex adaptive systems.

6. Evolutionary Origin and Major Transitions

Spontaneous symmetry breaking explains the evolutionary origination of this division. Initially, molecules may be undifferentiated, performing both catalytic and template functions. Small asymmetries, subject to multilevel selection, trigger bifurcation into specialized classes:

• One class (transmitter) sacrifices catalytic capability for fidelity of replication.
• The other (expressor) maximizes functional performance at the cost of reliable self-propagation.

This process parallels key evolutionary transitions such as the emergence of distinct germ and soma, reproductive and somatic castes in social insects, and the micronucleus–macronucleus distinction in ciliates. The underlying symmetry-breaking feedback induced by conflicting selection pressures is the formal origin, as specified in the mathematical modeling of (Takeuchi et al., 6 Aug 2025).

7. Broader Significance

Generalising the Central Dogma as a division of labour between information transmission and expression delivers explanatory economy for evolutionary biologists, cell theorists, and systems theorists investigating information management across biological hierarchies. It clarifies the evolutionary rationale for the unidirectional flow of information first articulated by Crick and reveals the universality of this partition across molecular, cellular, organismal, and social systems. By reframing the Central Dogma as a principle of informational insulation and functional expression, the model facilitates comparative analyses, provides predictive hypotheses for the evolution of complexity, and guides reinterpretations of major evolutionary innovations (Takeuchi et al., 6 Aug 2025).