Turritopsis dohrnii
Introduction
Turritopsis dohrnii (previously classified as Turritopsis nutricula),[1] commonly known as the immortal jellyfish or the Benjamin Button jellyfish,[2] is a small species of jellyfish known for its unique ability to revert back to an earlier life stage through transdifferentiation.[3][4] This ontogeny reversal renders the organism virtually immortal as this process has the potential to repeat itself indefinitely, although organismal death does still occur in its natural environment.[5] Reverse development can be triggered by a variety of stressors including starvation, changes in temperature or salinity, physical damage, or age-related deterioration.[4]
Although a rare ability, reverse development has been reported in several other Cnidaria species. Some of these include Laodicea undulata,[6] Aurelia sp.,[7] Hydractinia carnea,[3] Podocoryne carnea, Eleutheria dichotoma, Cladonema sp. and Cladonema uchidai, and Perarella schneideri.[5] However, these species can only undergo reverse development during the early stages of medusa bulb development. What makes Turritopsis dohrnii unique is its ability to revert after sexual maturation.[5]
The immortal nature of Turritopsis dohrnii makes it of interest for research in aging, cancer, and regenerative medicine.
Life Cycle
If produced sexually, the life cycle of Turritopsis dohrnii begins with planula larvae, fertilized eggs that settle on the seafloor.[8] From there, it develops into its hydroid stage. In this stage, it now takes on the form of stolons and polyps that reproduce asexually to form a colony. Immature medusae then bud off of the polyps and develop into sexually mature medusae, characterized by the presence of at least 16 tentacles,[9] within 18 to 30 days depending on the temperature of their environment.[5] The mature medusae may then release gametes that form planula larvae if they undergo fertilization, repeating the cycle. However, unlike other species, this is not the only option Turritopsis dohrnii has for restarting the cycle. If faced with unfavorable conditions or physical stresses (such as starvation, changes in temperature or salinity, physical damage, or age-related deterioration)[4] in the immature medusa stage, the organism will skip the maturation and sexual reproductive stages and revert back to the hydroid stage. All mature medusae will spontaneously regress back to the hydroid stage as well, whether or not they face adverse environmental conditions.[5] This reverse development is likely the result of senescence-related stress.
Genetics
Microbial Relationships
Medical Potential
Conclusion
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References
- ↑ Schuchert P. Revision of the European athecate hydroids and their medusae (Hydrozoa, Cnidaria): families Oceanidae and Pachycordylidae. Revue suisse de Zoologie. 2004 Jun 1;111(2):315-70. Available from: https://www.semanticscholar.org/paper/Revision-of-the-European-athecate-hydroids-and-and-Schuchert/e3d3dce80157e5ee98ecbe0bbe7d35eb36cbe82b?p2df
- ↑ Than K. "Immortal" Jellyfish Swarm World's Oceans [Internet]. National Geographic. 2009. Available from: https://www.nationalgeographic.com/animals/2009/01/immortal-jellyfish-swarm-oceans-animals/
- ↑ 3.0 3.1 Schmich J, Kraus Y, De Vito D, Graziussi D, Boero F, Piraino S. Induction of reverse development in two marine Hydrozoans. Int J Dev Biol. 2007 Feb 1;51:45–56. Available from: https://www.researchgate.net/publication/6617831_Induction_of_reverse_development_in_two_marine_Hydrozoans
- ↑ 4.0 4.1 4.2 Piraino S, De Vito D, Schmich J, Bouillon J, Boero F. Reverse development in Cnidaria. Canadian Journal of Zoology. 2004 Nov 1;82(11):1748-54. Available from: https://www.researchgate.net/profile/Stefano_Piraino/publication/249542511_Reverse_development_in_Cnidaria/links/004635220749d81dc3000000/Reverse-development-in-Cnidaria.pdf
- ↑ 5.0 5.1 5.2 5.3 5.4 Piraino S, Boero F, Aeschbach B, Schmid V. Reversing the life cycle: medusae transforming into polyps and cell transdifferentiation in Turritopsis nutricula (Cnidaria, Hydrozoa). The Biological Bulletin. 1996 Jun 1;190(3):302-12. Available from: https://www.journals.uchicago.edu/doi/pdfplus/10.2307/1543022?casa_token=VCv_136r__UAAAAA%3ARVFGUXoAfbOsfuX2x2l8RiTdYNa4mgvDPrnVFQEo5KUbmRat544_LD8iRbOzKJjDNuSi38-gjDo7&
- ↑ De Vito D, Piraino S, Schmich J, Bouillon J, Boero F. Evidence of reverse development in Leptomedusae (Cnidaria, Hydrozoa): the case of Laodicea undulata (Forbes and Goodsir 1851). Marine Biology. 2006 May 1;149(2):339-46. Available from: https://link.springer.com/article/10.1007%2Fs00227-005-0182-3
- ↑ He J, Zheng L, Zhang W, Lin Y. Life cycle reversal in Aurelia sp. 1 (Cnidaria, Scyphozoa). PloS one. 2015 Dec 21;10(12):e0145314. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4687044/
- ↑ Matsumoto Y, Piraino S, Miglietta MP. Transcriptome characterization of reverse development in Turritopsis dohrnii (Hydrozoa, Cnidaria). G3: Genes, Genomes, Genetics. 2019 Dec 1;9(12):4127-38. Available from: https://www.g3journal.org/content/ggg/9/12/4127.full.pdf
- ↑ Martell L, Piraino S, Gravili C, Boero F. Life cycle, morphology and medusa ontogenesis of Turritopsis dohrnii (Cnidaria: Hydrozoa). Italian Journal of Zoology. 2016 Jul 2;83(3):390-9. Available from: https://www.tandfonline.com/doi/full/10.1080/11250003.2016.1203034
Edited by Bailey Fitzgerald, student of Joan Slonczewski for BIOL 116 Information in Living Systems, 2020, Kenyon College.
