OCT 25, 2016 08:49 AM PDT

Footage of Cell Action During Limb Regeneration is Captured

WRITTEN BY: Carmen Leitch
For the first time, researchers have taken recordings of the behavior of cells in the epidermis as adult limbs regrow following amputation. In new work published in the journal eLife, investigators from the Institute of Functional Genomics in Lyon (Institut de Génomique Fonctionnelle de Lyon, IGFL) in France captured continuous live imaging of a leg undergoing regeneration in a close relative of the common sand hopper, the crustacean Parhyale hawaiensis. That shellfish has been used as a model of limb regrowth since 2014, when scientists including Michalis Averof, Director of Research at the IGFL and senior author of the current study, introduced it.
 
Image of a regenerating crustacean leg./ Credit: Frederike Alwes

"Parhyale hawaiensis is well suited for imaging limb regrowth. The animals have relatively rapid limb regeneration, requiring as little as one week for young adults to fully regrow their legs," Averof explained. "Also, their tiny limbs enable us to image the regeneration process in unprecedented cell-by-cell detail through their entire thickness." You can see the organism, and the collection of its embryos, in the video below.
 

The research team labeled proteins in the epidermal cells of the limbs with fluorescence that would allow them to visualize and record the regeneration. Using microscopy, continuous recordings were made over the first few days of regrowth, during which the fluorescently labeled proteins were observable. Live imaging of the regenerating leg is shown below. Arrowheads are highlighting two apoptotic nuclei.
 


"Using this method, we identified a specific sequence of events and cell behaviors that unfold during limb regrowth," commented the first author of the report, Frederike Alwes.

"These include wound closure, followed by a quiet period when the epidermal cells migrate slowly towards the site of the wound, which then leads to extensive cell division and movement as the new leg starts to develop its shape. We were surprised to see that there was a sharp transition between the last two stages, which suggests the cells were coordinated by a common signal."
 


Additionally, the researchers determined that specialized stem cells are not required for the regrowing process. Most of the epidermal cells in the leg stump simply rearranged and divided, building up the new segments of leg.
 
"Traditionally, insight into cell behavior during limb regrowth has been gathered by imaging fixed samples and attempting to fill in the missing pieces, due to the difficulties in tracking cells during regeneration in active adult animals. With the ability to track the movements and behavior of single cells individually through time, we now have the means to understand the cellular dynamics of the regeneration process, which could not have been reconstructed from fixed material,” explained Alwes.

"While our paper focuses mostly on the behavior of epidermal cells, we now plan to extend this work to include all the different cell types that are involved in limb regrowth. The ultimate aim of our research is to explore how some animals can respond to a severe injury by regenerating an entire body part that was lost," Alwes concluded.
 
Sources: AAAS/Eurekalert! via eLifesciences.org/Agence Nationale de la Recherche, eLife
 
About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 21, 2019
Cancer
SEP 21, 2019
An Ointment to Stop Skin Cancer Growth
Russian scientists are developing an ointment to undermine the growth of skin cancer, according to a review recently published in Molecules. One in three c...
SEP 21, 2019
Cell & Molecular Biology
SEP 21, 2019
Revealing Protein Interactions by Studying the Genome
Having an understanding of biology requires revealing the relationships and interactions between proteins....
SEP 21, 2019
Cell & Molecular Biology
SEP 21, 2019
Discovery of Bone Bits in Blood may Help Explain Vascular Calcification
As we age, calcium can build up in various tissues in the body, and cause them to harden in a process called calcification....
SEP 21, 2019
Microbiology
SEP 21, 2019
Antidepressants and Serotonin Impact Gut Microbiota
About 90% of the serotonin found in the human body is made in the gut. Some bacteria can encourage the release of serotonin from gut cells....
SEP 21, 2019
Neuroscience
SEP 21, 2019
New MRI scan can reveal molecular changes in the brain
MRI scans give us pictures of the brain that depict the physical structure of brain tissue. Now, researchers discovered a way to determine the biological m...
SEP 21, 2019
Genetics & Genomics
SEP 21, 2019
Genetic Cause for Tumor Progression
Researchers from the University of Delaware (UDEL), Harvard Medical School (HMS) and University of California, Los Angeles (UCLA), have discovered a ribonu...
Loading Comments...