Navigation Links
Study: Rare deep-sea starfish stuck in juvenile body plan

A team of scientists has combined embryological observations, genetic sequencing, and supercomputing to determine that a group of small disk-shaped animals that were once thought to represent a new class of animals are actually starfish that have lost the large star-shaped, adult body from their life cycle.

In a paper for the journal Systematic Biology (, Daniel Janies, Ph.D., a computational biologist in the department of Biomedical Informatics at The Ohio State University (OSU), leveraged computer systems at the Ohio Supercomputer Center (OSC) to help support his contention that class-level status of Xyloplax does not reflect their evolutionary history.

"Although Xyloplax does not represent a new class, it an even more interesting animal now because it represents a rare example of how natural selection can shape the whole the life cycle," he explained. "By omitting the large adult stage, Xylopax found how to make a living in the nooks and crannies of sunken timbers on the deep-sea floor."

Janies collaborated on the paper with co-authors Janet R. Voight, Ph.D., in the department of Zoology at the Field Museum of Natural History in Chicago, and Marymegan Daly, Ph.D., in the department of Evolution, Ecology and Organismal Biology at Ohio State.

Janies and his colleagues are examining echinoderms starfish, sea urchins and their close relatives as part of a study for the United States' National Science Foundation's Assembling the Tree of Life project. Several OSU scientists, including Janies and Daly, have won these grants, typically valued at $3 million over five years, to better understand the interrelationships of all forms of life (

As tree-of-life analyses are computationally difficult, the current project is enabled by the computational muscle of OSC's flagship system, the 9,500-node IBM 1350 Opteron "Glenn Cluster."

"Last year, OSC deployed a $4 million expansion to the Glenn Cluster with a specific focus on supporting researchers, like Drs. Janies and Daly, in Ohio's growing biosciences sector," said Ashok Krishnamurthy, interim co-executive director of OSC. "The center provides a world-class computing environment for amazing bioscience research projects at places like OSU's Department of Biomedical Informatics, the Research Institute at Nationwide Children's Hospital and the Cleveland Clinic."

The researchers examined both genetic and anatomical data to support their hypothesis, comparing Xyloplax with a total of 86 species representing major lineages of the five living classes of echinoderms (sea cucumbers, sea urchins, starfish, brittle stars, and sea lilies). For accurate comparisons, they applied several analytical methods to search for the shared mutations and changes in anatomy among the lineages.

The results describe the relationships in a phylogenetic tree representing the best-supported hypothesis on how Xyloplax evolved from other echinoderms. Phylogenetics is the study of the evolutionary relationships and changes among various biological species as they evolve from a common ancestor.

Prior to this study, molecular investigations of Xyloplax were limited, because specimens in two early collections in the 1980s were fixed in a solution which degrades DNA. Voight recently collected specimens of Xyloplax in the northeastern Pacific Ocean and carefully preserved them in ethanol. From these specimens, Daly was able to sequence several genes for Xyloplax. The newer specimens of Xyloplax also included several brooding females containing embryos, providing Janies with an unprecedented view of the creature's early development.

Janies and colleagues theorize that Xyloplax differs from other starfish species because it is progenetic that is, it has a rare, truncated life cycle that leaves the mature organism with features retained from its juvenile stages. For example, the arms of a starfish typically grow axially, like spokes of a wheel, as they develop from juveniles to adults, whereas Xyloplax grows along its circumference, like the wheel itself, and never develops arms.

"Irrespective of method or data sampling scheme, our results show that Xyloplax evolved from within starfish," Janies concluded. "Xyloplax is just a little starfish that has a strange body plan and habitat, so strange that many could not recognize it as a starfish until we unlocked its genome and development."


Contact: Jamie Abel
Ohio Supercomputer Center

Related biology news :

1. Study: urban black bears live fast, die young
2. Study: Bird diversity lessens human exposure to West Nile Virus
3. Study: Tropical wetlands hold more carbon than temperate marshes
4. Study: Wildlife need more complex travel plans
5. Study: Elderly Women can increase strength but still risk falls
6. UNC study: Text messaging may help children fight off obesity
7. Study: Did early climate impact divert a new glacial age?
8. Study: Excessive use of antiviral drugs could aid deadly flu
9. UNC study: Tinkering with the circadian clock can suppress cancer growth
10. Study: Fluid buildup in lungs is part of the damage done by the flu
11. Study: Health undervalued in reproductive rights debate
Post Your Comments:
Related Image:
Study: Rare deep-sea starfish stuck in juvenile body plan
(Date:4/15/2016)... April 15, 2016  A new partnership announced ... accurate underwriting decisions in a fraction of the ... priced and high-value life insurance policies to consumers ... With Force Diagnostics, rapid testing (A1C, Cotinine ... readings (blood pressure, weight, pulse, BMI, and activity ...
(Date:4/13/2016)...  IMPOWER physicians supporting Medicaid patients in ... standard in telehealth thanks to a new partnership with ... IMPOWER patients can routinely track key health measurements, such ... and, when they opt in, share them with IMPOWER ... local retail location at no cost. By leveraging this ...
(Date:3/29/2016)... RATON, Florida , March 29, 2016 ... or the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are ... DNA in ink used in a variety of writing ... theft. Buyers of originally created collectibles from athletes on ... through forensic analysis of the DNA. ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016 Houston Methodist ... the Cy-Fair Sports Association to serve as their ... agreement, Houston Methodist Willowbrook will provide sponsorship support, ... connectivity with association coaches, volunteers, athletes and families. ... the Cy-Fair Sports Association and to bring Houston ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... today announced the launch of the Supplyframe Design Lab . Located in ... to explore the future of how hardware projects are designed, built and brought ...
(Date:6/23/2016)... Andrew D Zelenetz ... Published recently in Oncology ... touchONCOLOGY, Andrew D Zelenetz , discusses the ... is placing an increasing burden on healthcare systems ... With the patents on many biologics expiring, interest ...
(Date:6/23/2016)... , June 22, 2016  Amgen (NASDAQ: ... the QB3@953 life sciences incubator to accelerate ... The shared laboratory space at QB3@953 was created to ... key obstacle for many early stage organizations - access ... the sponsorship, Amgen launched two "Amgen Golden Ticket" awards, ...
Breaking Biology Technology: