According to a recent study, the cnidocytes, or stinging cells that are found in sea anemones, hydrae, corals, and jellyfish and make humans cautious while wading in the ocean are also a great model for understanding the creation of new cell types.
Leslie Babonis, assistant professor of ecology and evolutionary biology in the College of Arts and Sciences, demonstrated that these stinging cells evolved by repurposing a neuron inherited from a pre-cnidarian ancestor in new research published in the Proceedings of the National Academy of Sciences on May 2.
Jellyfish's stinging cells
Knowing how specific cell types, such as stinging tentacles, emerge is one of evolutionary biology's main concerns, according to Babonis.
For over a century, scientists have known that cnidocytes grow from a pool of stem cells that also give rise to neurons (brain cells), but no one knew how those stem cells choose whether to create a neuron or a cnidocyte.
Understanding this mechanism in living cnidarians, according to Babonis, can give information on how cnidocytes developed in the first place, as per ScienceDaily.
These unexpected findings show how new genes gain new functions to promote biodiversity evolution.
Babonis suggested that the co-option of ancient cell types was an essential source of novel cell functions throughout the early evolution of animals.
Cnidocytes, which are common to species in the varied phylum Cnidaria, can discharge a poisonous barb or glob or allow cnidarians to shock prey or discourage attackers.
Cnidocytes are found solely in cnidarians, although neurons are found in many species, according to Babonis.
So, she and her colleagues at the University of Florida's Whitney Lab for Marine Bioscience investigated cnidarians, especially sea anemones, to learn how a neuron may be reprogrammed to produce a new cell.
The researchers demonstrated that cnidocytes arise by inhibiting the production of a neuropeptide, RFamide, in a subset of growing neurons and reusing those cells as cnidocytes using operational genomics in the starlet sea anemone, Nematostella vectensis.
Furthermore, the researchers discovered that a single cnidarian-specific regulatory gene controls both the neurological function of those cells and the cnidocyte-specific features.
According to Babonis, neurons and cnidocytes are both secretory cells capable of ejecting material out of the cell.
Neuropeptides are proteins secreted by neurons that swiftly transfer information to other cells. Cnidocytes produce harpoons laden with venom.
Furthermore, Babonis noted that this is the first research to establish that this logic exists in a cnidarian, hence this trait was likely to govern how cells differentiated from one another in the first multicellular creatures.
Also Read: New Jellyfish Species Discovered in the Philippines
How do jellyfish sting?
Jellyfish are translucent and composed of 95% water, so you'd assume there's not much to them. But you'd be mistaken.
The creature more sophisticated than you may expect, and their stinging cells are one of its most interesting features.
Cnidocytes are jellyfish stinging cells that are found on their tentacles. They are tiny chambers that contain a needle-like stinger.
When an outside force activates a stinger, the cell opens, allowing ocean water to flood in.
This causes the stinger to dart out into the source of the activity, where venom is discharged.
Everything happens in a millionth of a second. Although most jellyfish venom is harmless, some can be fatal.
The Indo-Pacific box jellyfish, for instance, delivers venom that causes the heart to constrict. There is a remedy, but the toxin works quickly, so anyone stung should seek medical assistance right away.
Related article: An "Entirely New" Species of Box Jellyfish Spotted in Sydney