functional cellular rejuvenation

Trait evidence (5)

• DOI:10.1242/jcs.86.1.263

  This is the first description of the restoration of a senescent defect by microinjection of young cytoplasmic components into Paramecium.

  Haga and Karino 1986, PMID:3654779; scientific abstract, directly read in the MED record. Young-cell cytoplasm restored sexual activity in senescent cells (about 700 fissions); recovery persisted for up to 20 fissions. Division rate and fertility after self-conjugation did not improve. This supports endpoint-specific recovery in treated old cells, not whole-cell or permanent rejuvenation. Full methods and figures were unavailable.

• DOI:10.1038/s41467-018-06154-9

  As this convergence was now downwards, doubling times decreased with each generation.

  Proenca et al. 2018, PMID:30213942, PMC6137065; Results, Stable equilibria are connected by aging and rejuvenation (Sec6), directly checked in primary XML. Actual Figure 4d was visually inspected: new-daughter lineages from the old-cell equilibrium converge toward faster growth over successive generations. These doubling times are derived from elongation rates, not direct interdivision intervals. Recovery is in descendants, not the same old mother. The tested MG1655 conditions do not establish all-environment recovery or a universal damage mechanism.

• DOI:10.1126/science.1204349

  Gametes (spores) generated by aged cells show the same replicative potential as gametes generated by young cells.

  Unal et al. 2011, PMID:21700873, PMC3923466; scientific abstract, directly checked in MED and an MIT-hosted author manuscript. Main text and Figure 1 support gamete replicative-potential reset. Figure 4 concerns the separate vegetative lifespan-extension experiment. Transient NDT80-dependent vegetative lifespan extension is a separate result and does not establish reversal of every aged-cell defect. Supplements and strain tables were not assessed. The retrieved PDF identifies the article but differs in size and checksum from MIT bitstream metadata; original deposited-byte identity remains unresolved.

• DOI:10.3390/microorganisms11010082

  The cloned immaturin gene induces sexual rejuvenation in both mature and senescent cells by microinjection.

  Haga 2023, PMID:36677375, PMC9865852; scientific abstract, directly checked in primary XML and PMC text. Results 3.1 uses rejuvenation for suppression of mating in mature cells: that maturation-state reset alone is outside this functional trait. Results 3.2 reports recovery of old-cell mating activity after transformation. Figure 6C measures total cell counts over four days, not direct division times, and lacks a young-cell growth comparator. Engineered treatment is not a natural canonical taxon example; inferred chemistry is not a proven mechanism.

• DOI:10.1016/j.isci.2022.103765

  Some cells rejuvenated immediately, even after extended starvation, but others only restarted growth after a delay or not at all.

  Cesar et al. 2022, PMID:35243217, PMC8858994; scientific abstract, directly checked against MED and primary XML. Boundary evidence: culture duration during stationary phase is not individual replicative age. Immediate regrowth can reflect preserved function, not recovery from a demonstrated deficit. Regrowth classes use area-derived growth rates; nongrowth during the observation window is not proof of irreversible death. Results 2.1 and 2.3, Discussion, limitations and classification methods were read; figures and raw data were not independently assessed.