Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Keeping biological tubes in check: New insights into tube size morphogenesis

24.01.2006


The function of tubular organs like the kidneys, lungs, and vessels of the vascular system is critically dependent on the length and diameter of the tubular branches of which they are composed. Several devastating pathological conditions like polycystic kidney disease and ischemias have been intimately linked to the aberrant sizes of tubular organs. Yet the underlying cellular and molecular mechanisms that control tube size are poorly understood, and, consequently, drugs that intervene in tubular organ disorders are lacking.



Over the past few years, the tracheal system of the fruit fly Drosophila has provided important general insights into epithelial organ morphogenesis. The fly’s tracheal system is a tubular network that functions in respiration by transporting oxygen throughout the insect body. In two separate new studies, researchers have taken advantage of the usefulness of the Drosophila tracheal system as a model for understanding the development of tubular organs. Both studies point to the important role played in this process by the luminal extracellular matrix (ECM)--a scaffold of sorts that provides structure to surrounding cells and tissues. Past work had shown that inside the tracheal tube, or lumen, the polysaccharide molecule chitin forms a cylinder that is essential for the coordinated dilation of the surrounding epithelium to its normal mature size: Mutants lacking chitin show tubes with irregular diameter.

In one of the new studies, a group led by Christos Samakovlis at Stockholm University has revealed further evidence for an "instructive" function of the luminal ECM in tube size control. They found that while uniform expansion of tube diameter requires the growth of a luminal chitin scaffold, the subsequent modification of this chitinous mandrel by specialized enzymes (called chitin deacetylases) instructs the termination of tube elongation. Mutations in two genes encoding these enzymes disrupt tubular morphogenesis. The authors’ additional discovery that proper luminal localization of one of the chitin deacetylases requires a specialized secretory pathway and intact structures called paracellular septate junctions provides a mechanistic model for tracheal tube size regulation.


The other new study, from Stefan Luschnig and colleagues at Bayreuth University, Germany, and at Stanford University, reports a similar set of findings. These researchers also identified the two chitin deacetyase genes as specifically controlling tube length. As did the Samakovlis group, the researchers found that mutations in these genes, called serpentine (serp) and vermiform (verm), cause excessively elongated and tortuous tracheal tubes. Unlike previously characterized genes, serp and verm are not required for producing chitin, but rather are required for its normal fibrillar structure. The findings of the two groups suggest that tube length is controlled by modulating physical properties of the chitin cylinder. These properties may be sensed by tracheal cells, mediating the restriction of cell elongation.

Given the many similarities in the developmental mechanisms and cellular designs of tubular organs across species, the distinct roles of the luminal ECM in tracheal tube size control provide new leads in the investigation of lumen size regulation in a variety of tubular organs.

Heidi Hardman | EurekAlert!
Further information:
http://www.current-biology.com

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Speed data for the brain’s navigation system

06.12.2016 | Health and Medicine

What happens in the cell nucleus after fertilization

06.12.2016 | Life Sciences

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>