Nav: Home

MSU biliogists: Bryozoans, brachiopods, and phoronida originate from the common ancestor

January 30, 2018

An associate of the Faculty of Biology of Lomonosov Moscow State University studied the nervous system of adult phoronida using modern methods and presented new facts in the long-lasting discussion about the taxonomy of invertebrates proving that phoronids, barchiopods, and bryozoans are relatives despite earlier arguments. The results of the work were published in Scientific Reports. The study was carried out within the framework of the "Noah's Ark" project supported with a grant of Russian Science Foundation (RSF).

Phoronida is a poorly studied phylum of invertebrates. Although it only contains about a dozen of species, these animals are widely spread and can be found in all areas of the World Ocean except for the Antarctic region. Phoronids live everywhere from littoral (the area near the shore) to 400-600 meter depth. The size of tne body varies from six millimeters to 50 centimeters. The soft boby is covered by the chitinous tube, which is embedded into soft or hard substrata. The anterior end of the body bear the lophophore - a tentacular structure, which is exposed into water and used for many functions such as collection of food particles, brooding, sensory, etc.

All animals with the lophophore (Phoronida, Brachiopoda, and Bryozoa) were traditionally gathered into one large group called Lophophorata. However, animals of these three phyla look completely different: bryozoans are similar to cnidarian polyps and sometimes form moss-like carpets (that is why they are also called moss animals); Phoronida resemble annelid worms, and brachiopods have shells that make them look like clams. Even the organs that unite them, the lophophores, are organized differently from each other: some have just a crown of tentacles, in others tentacles are located spirally or form a helicoidal coils. But all these animals have sessile type of life, are attached to substrate, and feed in similar manner.

For many years, scientists have been arguing whether these types are related. In the past 20 years genetics and molecular biology were included into the range of zoological methods. The genomes of bryozoans were slightly different from those of Phoronida and brachiopds, and biologists started to believe that the former type was unlikely to be closely related to the latter two. Still, they did not know how to regard bryozoans. Some considered them as sister group of all bilaterians (the animals in which the right and the left halves of the body are similar), and some included them into united group with other small colonial animals.

Elena Temereva used modern methods of immunocytochemistry and studied the innervation of the lophophore and tentacles in adult phoronid Phoronis ovalis. Comparative analysis of the organization of the lophophore nervous system in species of oall three phyla of Lophophorates has revealed the presence of homological nerve elements in the lophophore and allowed to conclude the homology of the lophophore.

"Based on these data we've supposed an idea that Phoronida and moss animals had originated from the common protophoronid ancestor. This conclusion based on morphological data contradicts the results of molecular and genetic studies conducted by other scientists," said Elena Temereva, doctor of biology, professor of Russian Academy of Sciences, and leading research associate of the department of invertebrate zoology at the Faculty of Biology, MSU.

The scientist studied the lophophoral nervous system using transmission electron microscopy, and immunocytochemistry and laser confocal microscopy.

"This work establishes the phylogeny of bryozoans. It is a conceptually important achievement for the understanding of the whole animal kingdom system and reconstruction of early evolutionary pathways of Bilateria," concluded Elena Temereva.

Lomonosov Moscow State University

Related Nervous System Articles:

Rare cells are 'window into the gut' for the nervous system
Specialized cells in the gut sense potentially noxious chemicals and trigger electrical impulses in nearby nerve fibers, according to a new study led by UC San Francisco scientists.
Study overturns seminal research about the developing nervous system
New research by scientists at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA overturns a long-standing paradigm about how axons grow during embryonic development.
Sympathetic nervous system is critical in regulating energy expenditure and thermogenesis
New study suggests that your brain, not your white blood cells, keeps you warm.
As fins evolve to help fish swim, so does the nervous system
The sensory system in fish fins evolves in parallel to fin shape and mechanics, and is specifically tuned to work with the fish's swimming behavior, according to new research from the University of Chicago.
Antibodies as 'messengers' in the nervous system
Antibodies are able to activate human nerve cells within milliseconds and hence modify their function -- that is the surprising conclusion of a study carried out at Human Biology at the Technical University of Munich (TUM).
Bioimaging: A clear view of the nervous system
A new and versatile imaging technique enables researchers to trace the trajectories of whole nerve cells and provides extensive insights into the structure of neuronal networks.
In the gut, nervous cells are the 'eyes and ears' of the immune system
A team of scientists in Portugal has discovered, in the mouse gut, a novel process that protects the bowel's lining against inflammation and microbial aggressions -- and fights them when they arise.
Biologists discover new strategy to treat central nervous system injury
Neurobiologists at UC San Diego have discovered how signals that orchestrate the construction of the nervous system also influence recovery after traumatic injury.
Delivery strategies of chemotherapy to the central nervous system
The blood-brain barrier and the blood-tumor barrier remain great obstacles to the drug delivery to brain tumors.
520-million-year-old fossilized nervous system is most detailed example yet found
A 520-million-year-old fossilized nervous system -- so well-preserved that individually fossilized nerves are visible -- is the most complete and best example yet found, and could help unravel how the nervous system evolved in early animals.

Related Nervous System Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...