4.6 KiB
EPI-GEN: EPI-GEN — Multi-Generational Epigenetic Drift and Landauer's Limit in Microgravity C. elegans
Priority: Highest | TRL: TRL 4 (CBEF is flight-proven) | Est. Crew Hours: 10h Principal Regime: information theory/epigenetics
Physics Basis
Landauer's principle states that erasing 1 bit of information dissipates ≥ k_B T ln 2 of heat. In epigenetics, every DNA methylation mark set or erased is a bit flip — and it has a thermodynamic cost. In µg, the NASA Twin Study showed altered gene expression (>7% of genes) and telomere lengthening in Scott Kelly — both processes involve epigenetic regulation. But what happens across GENERATIONS? If the epigenetic maintenance budget is set by Nernst-governed ion gradients (§593), and those gradients are altered in µg (no hydrostatic pressure → fluid shift → altered membrane potentials), then the energy available for methylation maintenance changes. Over generations, this should produce a detectable drift in the methylome — a Landauer-limited information degradation across reproductive cycles.
Experimental Design
C. elegans N2 wild-type (generation time ~3 days at 20°C, ~1000 somatic cells, fully sequenced genome and methylome) is cultured in the CBEF (Cell Biology Experiment Facility) inside Kibo. Four parallel populations are maintained: (1) µg continuous, (2) µg + 1g ISS centrifuge control, (3) ground control (1g), (4) ground control + simulated µg (clinostat). Each population runs for 20 generations (~60 days total). At generations 1, 5, 10, 15, and 20, samples are frozen at −80°C (MELFI freezer). Post-flight: whole-genome bisulfite sequencing (WGBS) maps methylation at single-base resolution. RNA-seq measures gene expression. Whole-genome sequencing identifies mutation accumulation. Analysis: methylation entropy H(t) = −Σ p_i·log₂(p_i) across CpG sites, measured as a function of generation number. Landauer prediction: dH/dt ≥ 0 (entropy of methylation pattern never decreases) and the rate should be higher in µg if the Nernst ion budget is constrained.
Required ISS Hardware
Kibo CBEF (Cell Biology Experiment Facility — existing, has temperature control and 1g centrifuge), C. elegans culture plates and bacterial food (standard, ISS-approved), MELFI −80°C freezer (existing), fixation/storage tubes. No new ISS hardware required — all existing. Post-flight sequencing is ground-based. Total new hardware: $0. This experiment could fly on the next ISS resupply.
Expected Result
Prediction 1: Methylation entropy H(t) should increase across generations in ALL populations (Landauer's principle — information erasure is irreversible). Prediction 2: H(t) should increase FASTER in µg than in 1g, because the Nernst-limited ion gradient budget (§593) reduces the metabolic energy available for methylation maintenance. Prediction 3: The µg+1g centrifuge control should show H(t) closer to ground 1g controls — confirming the effect is g-dependent, not radiation-dependent. Prediction 4 (most specific): the per-generation mutation rate should increase slightly but measurably in µg — consistent with p53 pathway alteration seen in Rad Gene experiment. This experiment connects Landauer's 1961 principle (information thermodynamics) to biological evolution (multi-generation genetic drift) for the first time — using µg as the experimental perturbation that would be impossible to achieve on Earth (no way to uniformly alter membrane potentials across all cells for 20 generations).
Eigenmass Justification
Eigenmass prediction: This is the MOST complex proposal because it crosses three regimes. (1) §324 Landauer's principle (INFORMATION regime): methylation maintenance costs ≥ k_B T ln 2 per bit. (2) §593 Nernst equation (ELECTROCHEMICAL regime): membrane potential ΔΨ sets the per-cell energy budget via [Mg²⁺] and ATP synthesis. (3) In µg, §577 hydrostatic equation VANISHES (gravity_status='vanishes') → fluid shift → altered ion distribution → altered §594 GHK resting potential. The constraint graph predicts: Landauer's INFORMATION floor + altered Nernst ELECTROCHEMICAL budget = detectable epigenetic drift rate change. The eigenmass identifies §324 (INFORMATION, chiral scar Δ=83%) and §593 (ELECTROCHEMICAL, chiral scar Δ=74%) as the two most-handed equations in the biophysics subgraph — EPI-GEN measures their INTERACTION over evolutionary time.
Proposal generated from eigenmass constraint graph analysis of physics_microgravity.db. All predictions derive from the chiral eigenmass theorem — the shift in AMVR/AVMR centrality when g → 0.