Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

WHOI Study Sheds Light on Tunicate Evolution

04.07.2011
Woods Hole Oceanographic Institution (WHOI) researchers have filled an important gap in the study of tunicate evolution by genetically sequencing 40 new specimens of thaliaceans, gelatinous, free-swimming types of tunicates. Their study was featured on the cover of the June issue of the Journal of Plankton Research.

Tunicates are a phylum of animals closely related to vertebrates, with a firm, rubbery outer covering called a tunic, from which the name derives.

“Thaliaceans have been poorly represented in previous studies of tunicate evolution,” said Annette Govindarajan of WHOI and Northeastern University, who performed the research along with WHOI Director of Research Laurence P. Madin and Ann Bucklin of the University of Connecticut at Avery Point. “Our study included 40 new sequences, which allowed us to make new insights on evolutionary relationships both within the Thaliacea, and between thaliaceans and other tunicates,” Govindarajan said.

Thaliaceans play an important role in many ocean ecosystems. They are known for their complex life cycles and their role in the transfer of organic matter from the surface to the deep sea.

The researchers made their discovery by sequencing the gene 18S rDNA. “Relatively little is known about evolutionary relationships within the Thaliacea and between thaliaceans and other tunicates -- for example, how they are related to various groups of ascidians, or sea squirts," Govindarajan said. “Our study presented a molecular phylogeny based on 18S rDNA sequences, including those from 40 newly obtained thaliacean samples.”

There are approximately 72 described species of thaliaceans classified in three subgroups-–the pyrosomes, salps, and doliolids, all of which are planktonic open-ocean animals that people seldom see. Govindarajan and her colleagues found a close relationship between thaliaceans and other types of tunicates, including sea squirts--bottom-dwelling tunicates that commonly overgrow docks and pilings. “The Thaliacea was monophyletic, indicating that the pyrosomes, salps, and doliolids arose from a common ancestor,” she said. “Within the salp lineage, we unexpectedly found the cyclosalp group to be closely related to another salp lineage, despite many morphological and behavioral differences. We also were able to clarify the uncertainty around the salp Weelia (Salpa) cylindrica. Previous work suggested that this species was closely related to species in the genus Salpa, but our results strongly indicated that it is distinct and warrants placement in a separate genus.”

Previous tunicate studies have been based on18S rDNA sequences, but thaliaceans were very poorly represented, Govindarajan said. “There are relatively few thaliacean specialists, and specimens are difficult to obtain and identify. Better thaliacean representation allowed us to make new insights on evolutionary relationships both within the Thaliacea and between thaliaceans and other tunicates.”

The research was funded by the National Science Foundation's Biological Oceanography Program.

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.

WHOI Media Relations | EurekAlert!
Further information:
http://www.whoi.edu

More articles from Ecology, The Environment and Conservation:

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht World Water Day 2017: It doesn’t Always Have to Be Drinking Water – Using Wastewater as a Resource
17.03.2017 | ISOE - Institut für sozial-ökologische Forschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>