Navigation Links
Tissue loss triggers regeneration in planarian flatworms
Date:9/2/2013

CAMBRIDGE, Mass. (September 3, 2013) Unlike humans, planarian flatworms have the remarkable ability to regrow any missing body part, making them an ideal model with which to study the molecular basis of regeneration.

Over the years scientists have learned that planarians mount recovery responses that differ depending on the severity of the injury they suffer. For example, a worm with a cut or a puncture wound reacts at the cellular and molecular levels quite differently from one that loses its head or tail. What has remained unclear, however, is just exactly how these responses are triggered.

Whitehead Institute Member Peter Reddien and two of his former graduate students, Michael Gavio and Danielle Wenemoser, address this longstanding question this week in the journal eLife, revealing a fascinating interplay of signals between two wound-induced genes.

According to the work of Gavino, Wenemoser, and Reddien, regeneration initiation in planarians is regulated by the expression of the genes Smed-follistatin (or fst) and Smed-activin-1 and -2 (or act-1 and act-2), that together act like a switch. After a planarian is wounded, the type of injury determines the level fst expressionthe more extreme the loss of tissue, the higher the level of fst expressed. At puncture wounds, fst expression is low, and regeneration is inhibited. However, following amputation, which results in major loss of tissue, fst levels rise and in turn inhibit Activin proteins, allowing regeneration to begin.

To the researchers' surprise, this interaction only affects regeneration and healing related to injury. Normal maintenance and cell turnover throughout the planarian body continue unaffected when fst is inhibited, even though these activities rely on the same neoblast cell population that creates new tissue during regeneration.

"It's a really great phenotype," says Reddien, who is also a Howard Hughes Medical Institute Early Career Scientist and an associate professor of biology at Massachusetts Institute of Technology. "It's one of the dream phenotypesto have a defect that's regeneration-specific, where the neoblasts are working. It's just regeneration that isn't working."

Such a phenotype could be a powerful tool in the further exploration of mechanisms that control regeneration. And many questions about these mechanisms remain.

"For example, the animals know how far to grow in regeneration, so they don't make tumorous outgrowths," says Wenemoser, who is now a postdoctoral researcher at Stanford University. "There's some kind of regulation on homeostatic size, so they're not growing out all wild and crazy. There's definitely more to investigate there."

Gavio agrees, and points out that the fst/act-1/2 switch may ultimately help scientists tease apart regeneration in other organisms, including humans.

"This regulation by activin and follistatin may be conserved in other systems," says Gavio, who is currently a postdoctoral researcher at Univeristy of California, San Francisco. "There are a lot of hints in the scientific literature that versions of activin or follistatin or both are activated by injury and may play a role in regeneration in other animals, but pinning the role of initiating regeneration to them hasn't happened yet."


'/>"/>

Contact: Nicole Rura
rura@wi.mit.edu
617-258-6851
Whitehead Institute for Biomedical Research
Source:Eurekalert

Related biology news :

1. Fetal tissue-derived stem cells may be ideal source for repairing tissues and organs
2. New protocol developed to decontaminate human fetal tissues used for cell transplantation
3. Ovarian cancer metastases influenced by factors in target tissues
4. Bacterial DNA may integrate into human genome more readily in tumor tissue
5. Improved material for laser welding of tissue in intestinal surgery
6. Building better blood vessels could advance tissue engineering
7. Even mild traumatic brain injuries can kill brain tissue
8. Molecular basis identified for tissue specific immune regulation in the eye and kidney
9. Stem cell-based bioartificial tissues and organs
10. UT Arlington bioengineer to use hybrid imaging system to see deep tissue
11. UT Arlington engineer wins NSF award to support microfluidic analyses of tissue, cell samples
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/1/2016)... , February 1, 2016 ... advancements to drive global touchfree intuitive gesture control market ... --> Rising sales of consumer electronics coupled with ... control market size through 2020 ... electronics coupled with new technological advancements to drive global ...
(Date:1/25/2016)... , Jan. 25, 2016   Unisys Corporation (NYSE: ... at John F. Kennedy (JFK) International Airport, New York ... (CBP) identify imposters attempting to enter the United ... belong to them. pilot testing of the system ... at three terminals at JFK during January 2016. --> ...
(Date:1/20/2016)... LONDON , Jan. 20, 2016 A ... positioned to directly benefit from the explosion in genomics ... from Howe Sound Research. A range of dynamic trends ... ...... - personalized medicine - pharmacogenomics - pathogen ... economies with large markets - greater understanding of the ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... ATLANTA , Feb. 11, 2016  Wellcentive ... a Portland, Oregon -based community ... to provide population health analytics, quality reporting and ... help FamilyCare strengthen its team of quality managers, ... reporting to the provider groups serving FamilyCare members. ...
(Date:2/11/2016)... ... February 11, 2016 , ... ... 150 years, continues today to pursue the highest level of accuracy and quality ... the AR9 Refractometer and the AR5 Refractometer. Accurate, reliable and tough enough ...
(Date:2/10/2016)... 10, 2016  The Maryland House of Delegates and ... that University of Maryland School of Medicine Dean ... of Maryland Medical System President and CEO Robert ... the highest honor given to the public by the ... Dean Reece and Mr. Chrencik for their contributions ...
(Date:2/10/2016)... , Feb. 10, 2016  Allergan plc (NYSE: ... announced that Brent Saunders , Allergan,s CEO and ... a fireside chat session at the RBC Capital Markets ... p.m. ET at The New York Palace Hotel in ... will be webcast live and can be accessed on ...
Breaking Biology Technology: