Scientists reveal the secret of eternal youth of a strange animal

In sea anemones, highly conserved genes ensure the differentiation of neurons and glandular cells throughout life.

Sea anemones are seemingly immortal animals. They appear to be immune to aging and the negative effects that humans experience over time. However, the exact reasons for their eternal youth are not fully understood.

The genetic fingerprint of the sea anemone Nematostella vectensis reveals that members of this incredibly ancient animal type use the same gene cascades for nerve cell differentiation as more complex organisms. These genes are also responsible for maintaining the balance of all cells in the body during the life of the anemone. These findings were recently published in the journal Cell reports by a group of developmental biologists led by Ulrich Technau of University of Vienna.

Almost all living organisms are made up of millions, if not billions, of cells that join together in complex ways to create specific tissues and organs that are made up of a range of cell types, such as a variety of neurons and gland cells. However, it is not clear how this critical balance of different cell types occurs, how it is regulated, and whether the different cell types of different animal organisms have a common origin.

Single-cell fingerprinting leads to common ancestors

The research group, led by the evolutionary developmental biologist Ulrich Technau, who is also the head of the Single-Cell Stem Cell Regulation Research Platform (SinCeReSt) at the University of Vienna, is deciphering the diversity and evolution of all types of nerve and glandular cells and their developmental origins of the sea anemone Nematostella vectensis.

To achieve this, they used single-cell transcriptomics, a method that has revolutionized biomedicine and evolutionary biology over the past decade.

“With this, whole organisms can be divided into individual cells – and all the currently expressed genes in each individual cell can be decoded. Different cell types differ fundamentally in the genes they express. Single-cell transcriptomics can therefore be used to determine the molecular fingerprint of each individual cell,” explains Julia Steger, first author of the current publication.

In the study, cells with an overlapping fingerprint were grouped. This allowed scientists to distinguish particular cell types or cells in transitional stages of development, each with unique combinations of expression. It also allowed the researchers to identify the common progenitor and stem cell populations of the different tissues.

To their surprise, they found that, contrary to earlier assumptions, neurons, glandular cells and other sensory cells originate from a common progenitor population, which could be confirmed by genetic tagging in living animals. Since some glandular cells with neuronal functions are also known in vertebrates, this may imply a very old evolutionary relationship between glandular cells and neurons.

Ancient genes in constant use

One gene plays a special role in the development of these common ancestors. SoxC is expressed in all precursor cells of neurons, gland cells and cnidocytes and is essential for the formation of all these cell types, as the authors were able to further show in knockout experiments.

“Interestingly, this gene is not unknown: it also plays an important role in the formation of the nervous system in humans and many other animals, which, together with other data, shows that these key regulatory mechanisms of neural cell differentiation appear to be conserved in the animal kingdom,” says Technau.

By comparing different life stages, the authors also found that in sea anemones, the genetic processes of neuronal development are maintained from the embryo to the adult organism, thus contributing to neuronal balance throughout the life of the organism. Nematostella Vectensis.

This is remarkable because, unlike humans, sea anemones can replace missing or damaged neurons throughout their lives. For future research, this raises the question of how the sea anemone manages to maintain these mechanisms, which in more complex organisms only appear in the embryonic stage, in the adult organism in a controlled manner.

Reference: “Single-cell transcriptomics identifies conserved regulators of neuroglandular lineages” by Julia Steger, Alison G. Cole, Andreas Denner, Tatiana Lebedeva, Grigoriy Genikhovich, Alexander Rees, Robert Reichl, Elisabeth Taudes, Mark Lasnig, and Ulrich Technau, September 20, 2022. , Cell reports.
DOI: 10.1016/j.celrep.2022.111370