Genomic Keys to Biological Immortality in Turritopsis dohrnii
Within the phylum Cnidaria, Turritopsis dohrnii—colloquially known as the ‘Immortal Jellyfish’—presents a profound biological paradox. Unlike its strictly mortal kin, this hydrozoan possesses the unique capacity for reverse ontogeny, the ability to revert from a sexually mature medusa to a juvenile polyp. A pivotal study published in the Proceedings of the National Academy of Sciences (PNAS) has recently elucidated the genomic architecture underpinning this phenomenon.
The researchers utilized a comparative genomic approach, juxtaposing T. dohrnii against its mortal relative, Turritopsis rubra. This comparison was crucial for isolating the specific molecular mechanisms of plasticity from background evolutionary noise. The findings indicate that biological immortality is not derived from a single novel gene; rather, it relies on the significant expansion and duplication of existing gene families.
This genomic amplification acts as a specific ‘rejuvenation toolkit’. The toolkit comprises genes associated with DNA replication, telomere maintenance, and redox regulation. Functionally, these mechanisms facilitate cellular transdifferentiation and the silencing of Polycomb repressive complexes, effectively resetting cell identity. By maintaining pluripotency and strictly regulating the redox environment, the organism circumvents the typical commitment to cellular senescence.
The implications of these findings extend beyond marine biology. By decoding the blueprint of cellular plasticity, this research offers critical insights into metazoan resilience. Ultimately, understanding these pathways provides a translational framework for human ageing research and regenerative medicine, suggesting that longevity relies on the robust regulation of fundamental cellular repair mechanisms.
Maria Pascual-Torner, Dido Carrero, Juan G. Pérez-Silva, et al. (2022) ‘Comparative genomics of mortal and immortal cnidarians unveils novel keys behind rejuvenation´
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