Do Jellyfish Hold the Secret to Aging?

Do Jellyfish Hold the Secret to Aging?

Ever wondered if you could reset your age?      

You’ve likely stumbled across various anti-aging “hacks” on social media, ranging from anti-aging skincare to diets and supplements. Aging can be a whirlwind of emotions and unexpected experiences, so it’s no surprise people are interested in learning how they can make this process a bit easier. In the world of science, great strides have been made in unpacking the secrets of human aging, especially as the world shifts to an aging population¹. This includes research on numerous diseases and treatments and increasing longevity. While improvements in biology research and technology (including AI!) have led to great discoveries, scientists still have quite a way to go in achieving immortality in humans.

While human immortality remains elusive, scientists have found a species that comes close. Have you ever heard of the immortal jellyfish? Scientists recently uncovered the mechanisms of how the Turritopsis dohrnii is able to, in simple terms, escape death.

Sounds unbelievable, doesn’t it? Let’s explore this further.

An Infinite Loop of Life

Turritopsis dohrnii, also known as immortal jellyfish, are a species of jellyfish found in the Caribbean and Mediterranean Seas. These jellyfish are so small, you likely wouldn’t even notice them, ranging from 1mm to 4.5mm in size! These jellyfish earned their name in 1988 after graduate students Christian Sommer and Giorgio Bavestrello were working on Turritopsis, collected samples of these in a jar to grow, and ended up forgetting about them. When Sommer and Bavestrello later checked on them, they realised that none of them had reached sexual maturity or died. They investigated this further, only to realise that the jellyfish were, quite literally, reverting back into their juvenile form².

Jellyfish start off as sperm and eggs. After fertilization, they develop into larvae—tiny, free-swimming organisms drifting in the currents. Once they find a surface in the sea, they attach themselves to continue their growth. After continued growth, they mature into polyps, bud off, and mature into their recognizable jellyfish form. Adult jellyfish are called medusa³.

One key to their immortality lies in the difference between their cells in the polyp and medusa forms. When mature jellyfish experience stress, environmental and physical, they reabsorb their tentacles and sink down to the surface of the sea as a bundle of cells. Within 2-3 days, this blob of cells forms into a polyp again and matures into medusa. In-lab colonies of immortal jellyfish have demonstrated that this can occur up to 10 times within 2 years! This cycle is driven by the process of transdifferentiation³.

Transdifferentiation is the conversion of cells from one type into another. All cells in an organism carry the same genes that encode for different functions and traits. Depending on the location and function of a particular cell, the molecular switches in that cell will control which genes are expressed or turned off⁴. For example, stem cells are self-renewing cells that can turn into any type of cell. These cells are usually programmed by different signals in the body. Transdifferentiation is a technique that allows us to manually turn on or off specific genes and change the cell type.