Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tube anemone has the largest animal mitochondrial genome ever sequenced

12.06.2019

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs. The human mitochondrial genome (mitogenome), for example, comprises 16,569 base pairs.

Pachycerianthus magnus

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

Credit: Sérgio Stampar

Tube anemones (Ceriantharia) are the focus of an article recently published in Scientific Reports describing the findings of a study led by Sérgio Nascimento Stampar (https://bv.fapesp.br/en/pesquisador/171695/sergio-nascimento-stampar/), a professor in São Paulo State University's School of Sciences and Letters (FCL-UNESP) at Assis in Brazil.

The study was supported by FAPESP via a regular grant for the project "Evolution and diversity of Ceriantharia (Cnidaria" and via its program São Paulo Researchers in International Collaboration (SPRINT) under a cooperation agreement with the University of North Carolina (UNC) at Charlotte in the US.

The mitogenome is simpler than the nuclear genome, which in the case of I. nocturnus has not yet been sequenced, Stampar explained. The human nuclear genome comprises some 3 billion base pairs, for example.

Another discovery reported in the article is that I. nocturnus and Pachycerianthus magnus (another species studied by Stampar's group, 77,828 base pairs) have linear genomes like those of medusae (Medusozoa), whereas other species in their class (Anthozoa) and indeed most animals have circular genomes.

I. nocturnus is found in the Atlantic from the coast of Patagonia in Argentina as far north as the East Coast of the US. P. magnuslives in the marine environment around the island of Taiwan in Asia. Both inhabit waters at most 15 m deep.

"I. nocturnus's mitogenome is almost five times the size of the human mitogenome," Stampar said. "We tend to think we're molecularly more complex, but actually our genome has been more 'filtered' during our evolution. Keeping this giant genome is probably more costly in terms of energy expenditure."

The shape of the mitogenomes in these two species of tube anemone and the gene sequences they contain were more surprising than their size.

Because they are closely related species, their gene sequences should be similar, but I. nocturnus has five chromosomes while P. magnus has eight, and each has a different composition in terms of genes. This kind of variation had previously been found only in medusozoans, sponges, and some crustaceans.

"Humans and bony fish species are more similar than these two tube anemones in terms of the structure of their mitochondrial DNA," Stampar said.

São Paulo coast and South China Sea

To arrive at these results, the researchers captured specimens in São Sebastião, which lies on the coast of São Paulo State in Brazil, and off Taiwan in the South China Sea. Small pieces of the animals' tentacles were used to sequence their mitogenomes.

The genomes of the two species hitherto available from databases were incomplete owing to the difficulty of sequencing them. After completing the study, the researchers published the genomes by gifting them to GenBan, a database maintained in the US by the National Center for Biotechnology Information (NCBI) at the National Institutes of Health (NIH).

Another obstacle to sequencing was the difficulty of collecting these animals because of their elusive behavior. In response to any potential threat, a tube anemone hides in the long leathery tube that distinguishes it from true sea anemones, making capture impossible.

"You have to dig a hole around it, sometimes as deep as a meter, and stop up the part of the tube buried in sand. All this must be done under water while carrying diving gear. Otherwise, it hides in the buried part of the tube and you simply can't get hold of it," Stampar said.

Thanks to the support of FAPESP's SPRINT program, Stampar and Marymegan Daly, a research colleague at Ohio State University in the US, established a partnership with Adam Reitzel and Jason Macrander at UNC Charlotte. Macrander, then a postdoctoral researcher under Reitzel, is a professor at Florida Southern College.

Reitzel and Macrander specialize in the use of bioinformatics to filter genomics data and assemble millions of small pieces of mitochondrial DNA into a single sequence. They used this technique to arrive at complete mitochondrial genomes for both species.

"In this technique, you sequence bits of the genome and link them in a circle. The problem is that this only works with circular genomes. Because we couldn't find a piece to close the circle, we realized the genome had to be linear, as it is for Medusozoa," Stampar said.

The discovery makes way for a possible reclassification of cnidarian species (hydras, medusae, polyps, corals and sea anemones). The tube anemones studied appear to form a separate group from corals and sea anemones and display some similarities to medusae.

However, more data will be needed before a definitive conclusion can be reached. The necessary data could come from the sequencing of these species' nuclear genomes, which Stampar and his group intend to complete by the end of 2019.

###

About São Paulo Research Foundation (FAPESP)

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at http://www.fapesp.br/en and visit FAPESP news agency at http://www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

Media Contact

Joao Carlos Silva
jsilva@fapesp.br
55-113-838-4381

 @AgencyFAPESP

http://www.fapesp.br 

Joao Carlos Silva | EurekAlert!
Further information:
http://agencia.fapesp.br/30727/
http://dx.doi.org/10.1038/s41598-019-42621-z

Further reports about: DNA FAPESP anemone corals gene sequences genomes mitochondrial DNA sea anemones

More articles from Life Sciences:

nachricht Tracing the evolution of vision
23.08.2019 | University of Göttingen

nachricht Caffeine does not influence stingless bees
23.08.2019 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Hamburg and Kiel researchers observe spontaneous occurrence of skyrmions in atomically thin cobalt films

Since their experimental discovery, magnetic skyrmions - tiny magnetic knots - have moved into the focus of research. Scientists from Hamburg and Kiel have now been able to show that individual magnetic skyrmions with a diameter of only a few nanometres can be stabilised in magnetic metal films even without an external magnetic field. They report on their discovery in the journal Nature Communications.

The existence of magnetic skyrmions as particle-like objects was predicted 30 years ago by theoretical physicists, but could only be proven experimentally in...

Im Focus: Physicists create world's smallest engine

Theoretical physicists at Trinity College Dublin are among an international collaboration that has built the world's smallest engine - which, as a single calcium ion, is approximately ten billion times smaller than a car engine.

Work performed by Professor John Goold's QuSys group in Trinity's School of Physics describes the science behind this tiny motor.

Im Focus: Quantum computers to become portable

Together with the University of Innsbruck, the ETH Zurich and Interactive Fully Electrical Vehicles SRL, Infineon Austria is researching specific questions on the commercial use of quantum computers. With new innovations in design and manufacturing, the partners from universities and industry want to develop affordable components for quantum computers.

Ion traps have proven to be a very successful technology for the control and manipulation of quantum particles. Today, they form the heart of the first...

Im Focus: Towards an 'orrery' for quantum gauge theory

Experimental progress towards engineering quantized gauge fields coupled to ultracold matter promises a versatile platform to tackle problems ranging from condensed-matter to high-energy physics

The interaction between fields and matter is a recurring theme throughout physics. Classical cases such as the trajectories of one celestial body moving in the...

Im Focus: A miniature stretchable pump for the next generation of soft robots

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.

Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The power of thought – the key to success: CYBATHLON BCI Series 2019

16.08.2019 | Event News

4th Hybrid Materials and Structures 2020 28 - 29 April 2020, Karlsruhe, Germany

14.08.2019 | Event News

What will the digital city of the future look like? City Science Summit on 1st and 2nd October 2019 in Hamburg

12.08.2019 | Event News

 
Latest News

Making small intestine endoscopy faster with a pill-sized high-tech camera

23.08.2019 | Medical Engineering

More reliable operation offshore wind farms

23.08.2019 | Power and Electrical Engineering

Tracing the evolution of vision

23.08.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>