Featured Research

from universities, journals, and other organizations

In regenerating planarians, muscle cells provide more than heavy lifting

Date:
August 15, 2013
Source:
Whitehead Institute for Biomedical Research
Summary:
By studying the planarian flatworm, a master of regenerating missing tissue and repairing wounds, scientists have identified an unexpected source of position instruction: the muscle cells in the planarian body wall. This is the first time that such a positional control system has been identified in adult regenerative animals.

In this image, muscle cells (green) in a planarian express 19 position control genes (red) that help the flat worm's stem cells know where they are in the body and which cells are needed to recreate missing tissues. Cell nuclei are stained blue.
Credit: Image courtesy of Cell Reports

By studying the planarian flatworm, a master of regenerating missing tissue and repairing wounds, Whitehead Institute Member Peter Reddien and his lab have identified an unexpected source of position instruction: the muscle cells in the planarian body wall.

"I was completely surprised. We had no idea it would be muscle," says Reddien, who is also an associate professor of biology at MIT. "Finding such a cellular system for positional control in an adult regenerative animal was unanticipated and is very informative for understanding regeneration."

For decades, researchers studying regeneration have focused on stem cells, largely because of their ability to spawn almost any type of replacement cell. In fact, the Reddien lab recently determined that cells known as cNeoblasts are the planarian stem cells that are able to regenerate all tissues in these animals.

Long neglected, however, has been the question of cell identity: how do cNeoblasts know where they are and which cells are needed to recreate missing tissues?

The Reddien lab and other labs had already identified various planarian genes involved in imparting positional information during regeneration and adult tissue maintenance, including regulators of Wnt, Bmp, and Fgf signaling pathways. These position control genes (PCGs) are highly conserved and many are found in other animals, including humans. But the cellular location of where those signals originated was unknown.

Reddien hypothesized that a certain type of cell expresses PCGs, possibly a unique type of cell that had not yet been described. To identify these cells, Jessica Witchley and Mirjam Mayer studied PCG expression in planarians and determined that all tested PCGs are indeed expressed in the same cells. They found that collagen, a telltale marker of planarian muscle cells, is also expressed in the same cell population. When part of a planarian was cut off, the muscle cells in the body wall altered which PCGs they expressed in response to the wounding. The lab's results are described in the August 29 issue of Cell Reports.

Until now, the planarian's muscles in the body wall were thought to primarily allow the worms to twist, turn, and respond to touch, in addition to providing some structure to their boneless bodies. Yet, these functions may also explain why muscle cells are so well suited to secrete the proteins coded for by the PCGs.

"Because the muscle cells extend throughout the organism, from head to tail, they are a great way to influence delivery of the PCGs' proteins and get signaling throughout the animal," says Witchley, a co-first author of the Cell Reports paper and a former technician in the Reddien lab. "Because the muscle fibers are long, when you cut the animal, it can immediately respond by contracting to close the wound, turning on wound-induced genes at that site, and eventually changing the pattern of expression to respond to the missing tissue."

The discovery of muscle cells' remarkable role in regeneration opens whole new areas of research.

"For one, we'd like to know how information from muscle cells at the wound site is actually conveyed to the stem cells and how the stem cells receive that information and respond," says Mayer, co-first author and former postdoctoral researcher in the Reddien lab. "And it would be very interesting to see if muscle cells have a position control role in other animals that is similar to what we've found in planarians."

This work is supported by the National Institutes of Health (NIH grant R01GM080639), the Keck Foundation, and the Helen Hay Whitney Foundation.


Story Source:

The above story is based on materials provided by Whitehead Institute for Biomedical Research. The original article was written by Nicole Giese Rura. Note: Materials may be edited for content and length.


Journal Reference:

  1. JessicaN. Witchley, Mirjam Mayer, DanielE. Wagner, JaredH. Owen, PeterW. Reddien. Muscle Cells Provide Instructions for Planarian Regeneration. Cell Reports, 2013; DOI: 10.1016/j.celrep.2013.07.022

Cite This Page:

Whitehead Institute for Biomedical Research. "In regenerating planarians, muscle cells provide more than heavy lifting." ScienceDaily. ScienceDaily, 15 August 2013. <www.sciencedaily.com/releases/2013/08/130815133105.htm>.
Whitehead Institute for Biomedical Research. (2013, August 15). In regenerating planarians, muscle cells provide more than heavy lifting. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/2013/08/130815133105.htm
Whitehead Institute for Biomedical Research. "In regenerating planarians, muscle cells provide more than heavy lifting." ScienceDaily. www.sciencedaily.com/releases/2013/08/130815133105.htm (accessed August 29, 2014).

Share This




More Plants & Animals News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Raw: Australian Sheep Gets Long Overdue Haircut

Raw: Australian Sheep Gets Long Overdue Haircut

AP (Aug. 28, 2014) Hoping to break the record for world's wooliest, Shaun the sheep came up 10 pounds shy with his fleece weighing over 50 pounds after being shorn for the first time in years. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Minds Blown: Scientists Develop Fish That Walk On Land

Minds Blown: Scientists Develop Fish That Walk On Land

Newsy (Aug. 28, 2014) Canadian scientists looking into the very first land animals took a fish out of water and forced it to walk. Video provided by Newsy
Powered by NewsLook.com
Huge Ancient Wine Cellar Found In Israel

Huge Ancient Wine Cellar Found In Israel

Newsy (Aug. 28, 2014) An international team uncovered a large ancient wine celler that likely belonged to a Cannonite ruler. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins