Scientists discover primitive gut's role in left-right patterning

March 6, 2012

Scientists have found that the gut endoderm has a significant role in propagating the information that determines whether organs develop in the stereotypical left-right pattern. Their findings are published 6 March 2012 in the online, open-access journal PLoS Biology.

Superficially, we appear bilaterally symmetrical. Nonetheless, the stereotypical placement of our organs reveals a stereotypical internal asymmetry. For example, the heart is located on the left, while the liver is located on the right side. How this inherent left-right asymmetry is established is an area of interest, because of both its intrinsic biological significance, as well as for its medical applications.

In the mouse, which is an experimentally tractable mammalian model system, a body of work has shown that the initial event that breaks left-right symmetry occurs at the node, a specialized organ located in the midline of the developing embryo. How this initial asymmetry at the node leads to a cascade of events propagating laterality information to a distant location within the embryo has been a major question in the field for over a decade. Previous experiments have shown that this cascade results in the activation of a on the left side of the embryo, ultimately leading to asymmetric organ formation. If the cascade fails to be propagated, left-right asymmetry fails to be established.

Kat Hadjantonakis and colleagues at the Sloan-Kettering Institute of the Memorial Sloan Kettering Cancer Center in New York now report that the asymmetric signals generated at the node are transferred to the extremity of the embryo across an epithelium residing on the embryo's surface. This epithelium, the gut endoderm, is the tissue containing the for the epithelial lining of the respiratory and digestive tracts and associated organs such as lungs, liver and pancreas.

Hadjantonakis and colleagues noted that lacking the HMG domain-containing transcription factor Sox17 exhibit defects in the formation of the gut endoderm and subsequently fail to establish left-right . They went on to demonstrate that cell-to-cell communication across gap junctions located within the gut endoderm epithelium is the mechanism of left-right information relay.

Explore further: Mechanism uncovered for the establishment of vertebrate left-right asymmetry

More information: Viotti M, Niu L, Shi S-H, Hadjantonakis A-K (2012) Role of the Gut Endoderm in Relaying Left-Right Patterning in Mice. PLoS Biol 10(3): e1001276.doi:10.1371/journal.pbio.1001276

Related Stories

Recommended for you

Success in the 3-D bioprinting of cartilage

April 28, 2017

A team of researchers at Sahlgrenska Academy has managed to generate cartilage tissue by printing stem cells using a 3-D-bioprinter. The fact that the stem cells survived being printed in this manner is a success in itself. ...

Mouse teeth providing new insights into tissue regeneration

April 27, 2017

Researchers hope to one day use stem cells to heal burns, patch damaged heart tissue, even grow kidneys and other transplantable organs from scratch. This dream edges closer to reality every year, but one of the enduring ...

Dentistry research ID's novel marker for left-handedness

April 27, 2017

Individuals with a slender lower face are about 25 percent more likely to be left-handed. This unexpected finding was identified in 13,536 individuals who participated in three national surveys conducted in the United States.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.