Is THIS the secret to immortality? Experts reveal how the hydra is able to infinitely regenerate itself, and the same trick could one day be used in human muscles

Until now, it was believed that hydras used chemical signals to regrow
But new research suggests that pieces of hydras also have structural memory
When shredded, the scraps form into spheres, and the cytoskeleton directs cells how to align into the body again

Published: 09:18 EST, 8 February 2017 | Updated: 10:21 EST, 8 February 2017

e-mail

View
comments

It is possibly the most resilient creature in nature, with the ability to be shredded into pieces and still regrow into a healthy animal.

And now researchers believe they may have found an explanation for how hydras are able to infinitely regenerate their bodies.

The findings provide strong evidence that these tiny organisms are immortal, with the ability to escape the ageing process.

The research could help scientists find ways to regenerate and repair damaged muscles in humans.

Scroll down for video

Hydra is a genus of small, simple, freshwater animals that can infinitely regenerate their bodies. Researchers believe that the creatures are immortal, with the ability to escape the ageing process

WHAT IS A HYDRA?

Hydra is a genus of small, simple, freshwater animals.

Hydra are predatory animals and can be found in most unpolluted freshwater ponds, lakes, and streams in the temperate and tropical regions.

They are multicellular organisms which are usually just a few millimetres long.

Hydra have a tubular body up to 10 mm long when extended, secured by a simple adhesive foot called the basal disc.

At the free end of the body is a mouth opening surrounded by one to 12 thin, mobile tentacles.

If hydra are alarmed or attacked, the tentacles can be retracted to small buds and the body column itself can be transformed to a small gelatinous sphere.

Until now, it was believed that hydras used chemical signals to regrow parts of their body.

But researchers from the Israel Institute of Technology suggest that pieces of hydras also have structural memory that helps them shape their body plan according to the pattern inherited by the animal's skeleton.

When regenerating, hydras use a tough network of stringy protein fibres – the cytoskeleton – to realign their cells.

But when pieces are cut or torn from hydras, the cytoskeleton pattern survives and becomes part of the new animal.

The pattern generates a small, but potent amount of mechanical force that shows cells how they should line up.

This mechanical force serves as a form of memory that stores information about the layout of the hydra's body.

Kinneret Keren, senior author of the study, said: 'You have to think of it as part of the process of defining the pattern and not just an outcome.'

In the study, the researchers shredded hydras into tiny pieces, and observed they regenerated. Firstly, the scraps folded into little balls (left), before stretching out into a tube (middle) and finally into new body parts (right)

In the study, the researchers shredded hydras into tiny pieces, and observed they regenerated.

HOW HYDRA REGENERATE

When regenerating, hydras use a tough network of stringy protein fibres – the cytoskeleton – to realign their cells.

But when pieces are cut or torn from hydras, the cytoskeleton pattern survives and becomes part of the new animal.

The pattern generates a small, but potent amount of mechanical force that shows cells how they should line up.

This mechanical force serves as a form of memory that stores information about the layout of the hydra's body.

They found that the scraps folded into little balls.

Ms Keren said: 'If you take a strip or a square fragment and turn it into a sphere, the fibres have to change or stretch a lot to do that.'

But some portions retain their pattern, and as the hydra tissue ball stretches into a tube and grows a mouth, the new body parts follow the pattern dictated by the cytoskeleton to form the original hydra.

Tampering with the cytoskeleton is enough to prevent hydras from reforming.

While hydras are much simpler than most creatures in the animal kingdom, the basic pattern of aligned cytoskeletal fibres is common in many organs, including human muscles and hearts.

The researchers hope that their findings in hydra could lead to a better understanding of how mechanics integrate with biochemical signals to shape tissues and organs in other species.

Ms Keren added: 'The actomyosin cytoskeleton are the main force generator across the animal kingdom. This is very universal.'

In 2015, researchers at Pomona College in California published findings of an eight-year study into hydra behaviour.

Researchers believe that hydra can live forever under the right circumstances, although this is unlikey in nature as hydra are exposed to the normal dangers of the wild - predation, contamination, diseases

Researchers recreated a little oasis for the hydras and gave them fresh water three times a week and fed them fresh brine shrimp.

They found that the death rates of all the specimens were constant and very low.

The results showed there was one death per 167 hydras each year and 80 per cent of the specimens' death rate remained constant, no matter their age and fertility.

Daniel Martínez, who led the study, said: 'I do believe that an individual hydra can live forever under the right circumstances.

'The chances of that happening are low because hydra are exposed to the normal dangers of the wild - predation, contamination, diseases.'