Navigation Links
Bird embryo provides unique insights into development related to cancer and wound healing
Date:3/23/2011

Avian embryos could join the list of model organisms used to study a specific type of cell migration called epiboly, thanks to the results of a study published this month in the journal Developmental Dynamics. The new study provides insights into the mechanisms of epiboly, a developmental process involving mass movement of cells as a sheet, which is linked with medical conditions that include wound healing and cancer.

The study, published online on March 15, explains how epithelial cells expand as a sheet and migrate to engulf the entire avian egg yolk as it grows. It also reveals the presence of certain molecules during this process that have not been previously reported in other major developmental models, including Xenopus frogs and zebrafish.

"These molecules and mechanisms of early development in the avian embryo may demonstrate evolutionary differences across species in the collective movement of epithelial cells and motivate additional studies of avian embryo development," said Evan Zamir, an assistant professor in the George W. Woodruff School of Mechanical Engineering at Georgia Tech.

Matt Futterman, who worked on the project as a graduate student at Georgia Tech, and mechanical engineering professor Andrs Garca also contributed to this study. The research was funded by Zamir's new faculty support from Georgia Tech and by a grant to Garca from the National Institutes of Health.

In the study, the researchers conducted immunofluorescence and high-resolution confocal microscopy experiments to examine the spatial distribution and expression of five proteins -- vimentin, cytokeratin, β-catenin, E-cadherin and laminin -- as cells moved to wrap the yolk sac of quail embryos during development.

The results showed that during this process, four of the proteins -- vimentin, cytokeratin, β-catenin and E-cadherin -- appeared in the cells located at the free edge of the migrating cell sheet. Finding dense interconnected networks of both vimentin and cytokeratin in the edge cells surprised the researchers.

"Since cytokeratin is generally associated with the epithelial phenotype and vimentin is generally associated with the mesenchymal phenotype, it's rare to see them expressed in the same cells, but this does occur in metastasizing tumor cells," said Zamir.

Cells expressing the mesenchymal phenotype are typically found in connective tissues -- such as bone, cartilage, and the lymphatic and circulatory systems -- whereas cells of the epithelial phenotype are found in cavities and glands and on surfaces throughout the body.

This finding provides evidence that epithelial cells normally attached to a membrane surface underwent biochemical changes that enabled them to assume a mesenchymal cell phenotype, which enhanced their migratory capacity. This process, called partial epithelial-to-mesenchymal transition, has many similarities to the initiation of tumor cell metastasis and wound healing.

Since this epithelial and mesenchymal expression pattern in the edge cells has not previously been reported in Xenopus or zebrafish, it may be unique to the avian embryo. This discovery would make the avian embryo a valuable model for studying tumor cell migration and wound healing.

In addition to detailing protein expression in the quail embryo during development, the researchers also determined the origin of the new cells required at the migrating edge to cover the growing yolk. During development, the radius of the quail yolk doubles every day for the first few days, representing a hundreds-fold increase in the egg yolk surface area.

"For each individual cell that has to cover the egg yolk as it grows, the migration around the yolk is extraordinary, because it's such a large territory -- it'd be like an ant walking across the earth," explained Zamir.

Looking more closely at the edge cells, the researchers found strong evidence that expansion of the edge cell population was due exclusively to cells relocating from an interior region to the edge as the embryo expanded. The cells located at the free edge generated the bulk of the traction force necessary for expansion and towed the cells within the interior of the epithelium.

"These experiments confirm that edge cell proliferation is not the primary mechanism for expansion of the edge cell population," noted Zamir. "And our observation of epithelial-to-mesenchymal transition in the edge cells explains how these epithelial cells might be changing phenotype to become migratory in this rapidly expanding sheet."

To determine if this study's findings are indeed unique to the avian embryo, Zamir plans to conduct further studies to characterize protein expression and cell migration in Xenopus and zebrafish.


'/>"/>

Contact: Abby Robinson
abby@innovate.gatech.edu
404-385-3364
Georgia Institute of Technology Research News
Source:Eurekalert  

Related medicine news :

1. Embryonic stem cells help deliver good genes in a model of inherited blood disorder
2. Single Embryo Beat Double Embryo Transfer in IVF Study
3. Scientists Spot Genetic Areas Key to Embryonic Development
4. States Now Fund Most Embryonic Stem Cell Research in U.S.
5. Newly discovered regulatory mechanism essential for embryo development and may contribute to cancer
6. First Patient Treated in U.S.-Approved Embryonic Stem Cell Trial
7. Most Americans Back Embryonic Stem Cell Research: Poll
8. Video May Help Predict Which Embryos Will Survive IVF
9. Natural lung material is promising scaffold for engineering lung tissue using embryonic stem cells
10. Human embryonic stem cells purified in new, rapid technique
11. UCLA scientists isolate the first stages of tissue production in human embryonic stem cells
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Bird embryo provides unique insights into development related to cancer and wound healing
(Date:4/21/2017)... IL (PRWEB) , ... April 21, 2017 , ... Chicago ... revolutionize the removal of osteoma. An osteoma is a benign bony lump located on ... the eye and can cause difficulties with sight and pain. Dr. Shah has discovered ...
(Date:4/21/2017)... ... April 21, 2017 , ... Dudnyk has announced the launch of its ... that the full potential of specialty and orphan brands can only be achieved when ... , “The Unifying Effect is at the heart of a true partnership between our ...
(Date:4/21/2017)... ... April 21, 2017 , ... The Hong Kong Polytechnic University ... printing facility among higher education institutions in Hong Kong to support teaching, learning and ... the range and quantity of facilities in Hong Kong. , With an area ...
(Date:4/21/2017)... ... 2017 , ... Airway Management, the medical device manufacturer of ... and well renowned Asian distributor, Discovery Sleep. The agreement involves the ... and will stabilize and strengthen Airway’s presence with a dedicated, reputable medical device ...
(Date:4/21/2017)... ... April 21, 2017 , ... Providing for loved ones before one’s passing is ... where to even begin. “Now more than ever there are some questions that are ... and your family,” said attorney Lisa Edgar Dickman, founder of the Law Offices of ...
Breaking Medicine News(10 mins):
(Date:4/20/2017)... Eyevensys, a private biotechnology company developing its ... that enables the safe, local, sustained production of therapeutic ... of ophthalmic diseases, announces it has received approval from ... to advance its technology into clinical development. ... The EyeCET platform uses ...
(Date:4/19/2017)... The Mobile X-Ray product segment is the most ... the forecast period Mobile X-Ray segment is the ... X-Ray devices market, which is estimated to be valued at ... CAGR of 7% over the forecast period. Mobile X-Ray segment ... US$ 100 Mn in 2017 over 2016. The segment,s revenue ...
(Date:4/19/2017)... 19, 2017 The Global Effective Microorganisms ... 2022 report has covered and analysed the potential of Global ... market size, shares and growth factors. The report identifies and ... opportunities in the global market. ... Browse 152 Tables and Figures, 6 Major Company Profiles, ...
Breaking Medicine Technology: