Researchers have uncovered genetic clues that help explain why one jellyfish species seems to cheat mortality, at least for a time. In a study reported in a leading scientific journal, scientists describe how a specific jellyfish life cycle can break the usual pattern of aging. These creatures begin life as free-floating larvae, settle onto the ocean floor to form little polyp colonies, and later detach to become the familiar, free-swimming jellyfish. Yet the so-called immortal jellyfish, Turritopsis dohrnii, can reverse this cycle. When stressed or damaged, it can transform back into a blob-like stage and gradually rebuild into a polyp, effectively reversing aging rather than succumbing to time’s passage. This remarkable capability positions T. dohrnii as a natural model for studying aging and rejuvenation in the animal kingdom .
To understand the genetic foundations of this remarkable process, scientists at the University of Oviedo in Spain, along with collaborators, sequenced the jellyfish genome in order to map the genes involved in DNA protection, maintenance, and cellular renewal. The results showed that the immortal variety carries about double the number of gene copies linked to DNA repair pathways and genome safeguarding. With more copies available, these organisms can produce higher levels of protective and reparative proteins, which may help them withstand cellular stress and sustain younger-appearing tissues for longer periods. In addition, the researchers found unique genetic changes that seem to stabilize telomeres, the protective caps at chromosome ends. Since telomere length is closely tied to how quickly cells divide and how tissues age, these telomere-preserving mutations may contribute to delaying senescence in these jellyfish .
Beyond the static genome, the team also investigated the dynamic gene activity during the reverse metamorphosis from adult jellyfish back to the polyp stage. They discovered a coordinated shift in gene expression: developmental programs that ordinarily guide growth and differentiation are downregulated, effectively returning cells to a more primitive, undifferentiated state. Simultaneously, other genes are activated to re-specify cells so that they can re-differentiate into the polyp form. This reprogramming appears to reset aspects of the organism’s biology, enabling a cycle that reverses aging-like changes rather than accumulating them with time .
These results are not simply a curiosity about jellyfish biology. The authors of the work argue that the genetic components identified in T. dohrnii may inform understanding of human aging as well. If particular DNA repair mechanisms and telomere-stabilizing processes can be modulated in other animals, including humans, there could be avenues to slow some age-associated deterioration or enhance cellular resilience. While translating these findings to clinical applications would require extensive research and careful consideration of species differences, the study offers a concrete demonstration that natural life-history strategies can reveal molecular targets relevant to aging, regeneration, and tissue maintenance .