Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Snout dated: Slow-evolving elephant shark offers new insights into human physiology

06.06.2019

Using different steroid hormones to activate a hormone receptor in a cartilaginous fish provides insights into origins and later evolution of crucial mechanism for survival of vertebrates living on land

The mineralocortoid receptor (MR) regulates water and sodium transport throughout cells and tissues, which is critical for controlling blood pressure and so, not surprisingly, the MR is common to all vertebrate animals. Aldosterone, which is a physiological steroid for land vertebrate MRs, evolved in lungfish (forerunners of land vertebrates), suggesting that the evolution of aldosterone was important in the conquest of land by preventing dehydration in animals living out of water.


An elephant shark, characterized by its distinctive snout.

Photo credit: Susumu Hyodo, University of Tokyo

And yet, aldosterone is absent in sharks and ray-finned fish, prompting the question of which steroids activate the MR in them, and the roles played by these steroids in humans.

In an unusual study, an international team of scientists from Japan, Singapore and the United States, led by Michael E. Baker, PhD, research professor at University of California San Diego School of Medicine, report that compared to humans, a different set of steroid hormones activate MR in elephant sharks, a species of cartilaginous fish that represents the oldest surviving group of jawed vertebrates.

The discovery, published in the June 4, 2019 issue of Science Signaling, not only highlights another evolutionary change as vertebrates transitioned from water to land, but suggests that MR may have other, critical roles in maintaining human health.

"Although the MR is traditionally thought of as a transcription factor that's important in regulating electrolyte transport in kidneys, it is becoming clear that the MR has physiological actions in non-traditional organs, including the brain and heart," said Baker.

"Our findings suggest that the activity of the MR in non-traditional organs is ancient and, indeed, evolved in a basal jawed vertebrate. Studies with elephant sharks support other research that shows the physiology of steroid hormones like aldosterone, cortisol and progesterone in other non-traditional tissues, such as ovary and testis, also may be important in human health."

The elephant shark (Callorhinchus milii) is an uncommon animal model. Known by several names, such as ghost shark, elephant fish and silver trumpeter, the species is found in waters off southern Australia. The smooth-skinned fish grow to a maximum size of four feet and pose no threat to humans. Their distinctive hoe-shaped, proboscis-like snout is used to detect prey, primarily shellfish and bottom-dwelling invertebrates, through movement and weak electrical fields.

Elephant sharks possess another unusual feature: They have the slowest evolving genome of all known vertebrates, "which makes them ideal for providing insights into how MR evolved in bony vertebrates, including humans," said the study's first author Yoshinao Katsu, PhD, assistant professor of biological science at Hokkaido University in Japan.

Baker, Katsu and colleagues in Singapore, Japan and Minnesota found that elephant shark MR responds to the same physiological corticosteroids (aldosterone, cortisol, corticosterone and 11-deoxycorticosterone) that activate MR in humans and other mammals. But another major steroid hormone -- progesterone -- triggers shark MR but does nothing in humans, rats, frogs or alligators.

"Because the synthesis of progesterone synthesis is simpler than either aldosterone, cortisol, corticosterone or 11-deoxycorticosterone, we propose that progesterone was an ancestral, maybe the ancestral steroid for MR," said Katsu.

As such, said the authors, the odd-looking elephant shark and its compact, slow-evolving genome provide a different, comparative way to look at and understand the evolution of humans and other vertebrates at the point when they became terrestrial creatures.

"Elephant shark proteins are a window into the past," said Baker.

###

Co-authors include: Satomi Kohno, St. Cloud State University, Minn.; Kaori Oka, Xiaozhi Lin and Sumika Otake, Hokkaido University, Japan; Nisha E. Pillai and Byrappa Venkatesh, Institute for Molecular and Cell Biology, Singapore; and Wataru Takai and Susumu Hyodo, University of Tokyo.

Media Contact

Scott LaFee
slafee@ucsd.edu
858-249-0456

 @UCSanDiego

http://www.ucsd.edu 

Scott LaFee | EurekAlert!
Further information:
http://dx.doi.org/10.1126/scisignal.aar2668

More articles from Life Sciences:

nachricht Biomarker predicts which pancreatic cysts may become cancerous
06.06.2019 | Washington University School of Medicine

nachricht Approved medications – new role in combating infections?
05.06.2019 | Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Cost-effective and individualized advanced electronic packaging in small batches now available

Fraunhofer IZM is joining the EUROPRACTICE IC Service platform. Together, the partners are making fan-out wafer level packaging (FOWLP) for electronic devices available and affordable even in small batches – and thus of interest to research institutes, universities, and SMEs. Costs can be significantly reduced by up to ten customers implementing individual fan-out wafer level packaging for their ICs or other components on a multi-project wafer. The target group includes any organization that does not produce in large quantities, but requires prototypes.

Research always means trying things out and daring to do new things. Research institutes, universities, and SMEs do not produce in large batches, but rather...

Im Focus: 2D crystals conforming to 3D curves create strain for engineering quantum devices

A team led by scientists at the Department of Energy's Oak Ridge National Laboratory explored how atomically thin two-dimensional (2D) crystals can grow over 3D objects and how the curvature of those objects can stretch and strain the crystals. The findings, published in Science Advances, point to a strategy for engineering strain directly during the growth of atomically thin crystals to fabricate single photon emitters for quantum information processing.

The team first explored growth of the flat crystals on substrates patterned with sharp steps and trenches. Surprisingly, the crystals conformally grew up and...

Im Focus: Experiments and calculations allow examination of boron's complicated dance

Work opens a path to precise calculations of the structure of other nuclei.

In a study that combines experimental work and theoretical calculations made possible by supercomputers, scientists have determined the nuclear geometry of two...

Im Focus: Fraunhofer HHI and IAF demonstrate the first wireless real-time video transmission using Terahertz

The Fraunhofer Heinrich Hertz Institute HHI develops next-generation wireless transmission systems (Beyond 5G) based on Terahertz (THz) technologies. The THz technology supports significantly higher data transmission rates than current 4G and 5G mobile wireless technologies. Researchers of the department Photonic Networks and Systems, in collaboration with the Fraunhofer Institute for Applied Solid State Physics IAF, have succeeded in transmitting a 4K video in real-time over a wireless THz link. This was the first time this technology was successfully realized in a real-time experiment. A wireless transmission capacity of 100 Gbit/s was demonstrated over the THz link.

Requirements placed on transmission capacities in communication networks are continuously growing, driven by new applications such as Industry 4.0, autonomous...

Im Focus: Colliding lasers double the energy of proton beams

Researchers from Sweden's Chalmers University of Technology and the University of Gothenburg present a new method which can double the energy of a proton beam produced by laser-based particle accelerators. The breakthrough could lead to more compact, cheaper equipment that could be useful for many applications, including proton therapy.

Proton therapy involves firing a beam of accelerated protons at cancerous tumours, killing them through irradiation. But the equipment needed is so large and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Approved medications – new role in combating infections?

05.06.2019 | Life Sciences

Researchers develop superconducting quantum refrigerator

05.06.2019 | Physics and Astronomy

Chemists could make 'smart glass' smarter by manipulating it at the nanoscale

05.06.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>