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Sea Creature Used to Research How Stem Cells Function in an Intact Animal

28th May 2023
A female individual of Hydractinia symbiolongicarpus. Body cells are shown in red; stem cells and maturing eggs in green
A female individual of Hydractinia symbiolongicarpus. Body cells are shown in red; stem cells and maturing eggs in green

A relative of corals and jellyfish, which can live for thousands of years, has been used to study the developmental potential of adult stem cells.

A research team in the Centre for Chromosome Biology, University of Galway, selected the cnidarian Hydractinia - a creature which is a close relative of jellyfish – for the project.

Cnidarians are a group of animals that includes corals and jellyfish and can be easily grown in the laboratory.

They have regenerative abilities and don’t appear to age during their life span extending over several thousand years.

The study, published in the international journal Current Biology, was led by Professor Uri Frank and PhD student Áine Varley,

They established this animal as a “model organism” for stem cell research, including the development of genetic tools that allow the generation of transgenic animals.

A major question in stem cell biology is the ability of stem cells to generate other cell types, such as neurons and muscle, throughout life, the team explains.

The team says it addressed the problem by transplanting a single stem cell from a donor animal to a recipient.

“The single transplanted stem cell was genetically labelled by fluorescent dyes, making it visible in the tissue of the recipient,” they explain.

After several months, progeny of the single transplanted stem cell gradually displaced the recipient’s own cells, they found.

“Eventually, a complete takeover occurred, thereby the recipient animal became genetically identical to the donor,” they say.

“Cnidarians are known for their exceptional regenerative ability,” Varley said.

“ Many of these animals can regenerate whole bodies from small tissue fragments,” she said.

“ Another unusual feature of cnidarians is the apparent lack of ageing; indeed, some cnidarians, such as corals, are known to live for thousands of years without experiencing any decline in their health,” she noted.

“These fantastic traits, which are uncommon in animals, are thought to depend on a population of adult stem cells that behave like embryonic cells in that they can renew all tissues, continuously,” she said.

“Hydractinia adult stem cells are functionally similar to human embryonic cells,” Prof Frank said.

“ The technology developed in this project allows us easy access to embryonic-like cells in an adult animal. The study has implications on our understanding of how stem cells function to contribute to tissue regeneration,” Frank said.

Lorna Siggins

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Lorna Siggins

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Lorna Siggins is a print and radio reporter, and a former Irish Times western correspondent. She is the author of Search and Rescue: True stories of Irish Air-Sea Rescues and the Loss of R116 (2022); Everest Callling (1994) on the first Irish Everest expedition; Mayday! Mayday! (2004); and Once Upon a Time in the West: the Corrib gas controversy (2010). She is also co-producer with Sarah Blake of the Doc on One "Miracle in Galway Bay" which recently won a Celtic Media Award

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Marine Wildlife Around Ireland One of the greatest memories of any day spent boating around the Irish coast is an encounter with marine wildlife.  It's a thrill for young and old to witness seabirds, seals, dolphins and whales right there in their own habitat. As boaters fortunate enough to have experienced it will testify even spotting a distant dorsal fin can be the highlight of any day afloat.  Was that a porpoise? Was it a whale? No matter how brief the glimpse it's a privilege to share the seas with Irish marine wildlife.

Thanks to the location of our beautiful little island, perched in the North Atlantic Ocean there appears to be no shortage of marine life to observe.

From whales to dolphins, seals, sharks and other ocean animals this page documents the most interesting accounts of marine wildlife around our shores. We're keen to receive your observations, your photos, links and youtube clips.

Boaters have a unique perspective and all those who go afloat, from inshore kayaking to offshore yacht racing that what they encounter can be of real value to specialist organisations such as the Irish Whale and Dolphin Group (IWDG) who compile a list of sightings and strandings. The IWDG knowledge base has increased over the past 21 years thanks in part at least to the observations of sailors, anglers, kayakers and boaters.

Thanks to the IWDG work we now know we share the seas with dozens of species who also call Ireland home. Here's the current list: Atlantic white-sided dolphin, beluga whale, blue whale, bottlenose dolphin, common dolphin, Cuvier's beaked whale, false killer whale, fin whale, Gervais' beaked whale, harbour porpoise, humpback whale, killer whale, minke whale, northern bottlenose whale, northern right whale, pilot whale, pygmy sperm whale, Risso's dolphin, sei whale, Sowerby's beaked whale, sperm whale, striped dolphin, True's beaked whale and white-beaked dolphin.

But as impressive as the species list is the IWDG believe there are still gaps in our knowledge. Next time you are out on the ocean waves keep a sharp look out!