Navigation Links
Why the thumb of the right hand is on the left hand side
Date:5/22/2009

This press release is available in German.

It is the concentration of a few signaling molecules that determines the fate of individual cells during the early development of organisms. In the renowned journal Current Biology, a team of molecular biologists led by Pia Aanstad of the University of Innsbruck reports that a variety of molecular mechanisms accounts for the interpretation of the concentration of the signaling molecule Hedgehog.

The development of an organism is a complex process to which a dozen or hundreds of signaling molecules contribute. Some of these molecules have dozens of functions in the fruit fly and in humans alike. One of these molecules Hedgehog controls the development of, for example, the extremities, the central nervous system, the teeth, eyes, hair, lung and the gastrointestinal tract. "What is most remarkable: The cells are told what to do not only because the molecule is present but also by the different concentrations of the molecules in the tissue", says group leader Pia Aanstad of the Institute for Molecular Biology of the University of Innsbruck. "The concentration of Hedgehog makes the thumb of the right hand grow on the left hand side and the thumb of the left hand grow on the right hand side." Thus, scientists define Hedgehog as a morphogen a signal that is concentration-dependent and controls the pattern formation of an organism. A mutation in this signaling pathway induces dramatic and embryonically lethal malformations in the early developmental stage such as the formation of just one central eye. Defects in the Hedgehog signaling pathway in humans are a cause for one of the most common birth defects holoprosencephaly. "Hedgehog genes are not new in evolution and the signaling pathway functions in the fly, mouse, fish and in humans similarly", says Pia Aanstad. In her research work she focuses on the zebra danio or zebra fish. Due to the short developmental cycle, the scientists are able to observe the development of the small tropic fish in fast motion. "We want to better understand how the cells process the signals of the signaling molecules and how they react."

Mutants do not react to high concentrations

Already during her time as a post doc in San Francisco, U.S., Pia Aanstad discovered a mutated zebra fish whose Hedgehog signaling pathway was disrupted. The fish showed a genetic alteration at the so-called Smoothened (Smo) protein, which is located at the cell membrane and transfers the Hedgehog signal into the cell. In 2005, Aanstad and her colleagues published a paper in the renowned journal Nature, in which they showed that Smo is concentrated at cilia (cellular projections) and also functions at the cilium. "By using high-resolution fluorescence microscopy, we have now shown that in the new mutants a small genetic alteration at the extracellular part of this protein inhibits localization in the cilia and that while the cells identify the Hedgehog signals, they interpret the concentration incorrectly", explains Pia Aanstad. "This is evidence for the notion that cells use various molecular mechanisms for interpreting different Hedgehog concentrations." This fact may also be of importance for the diagnosis and treatment of certain cancers (basal cell carcinoma), where the constant up-regulation of the Hedgehog signal is responsible for uncontrolled cell growth. Aanstad published the findings together with her colleagues from the University of California, San Francisco in the journal Current Biology.


'/>"/>

Contact: Pia Aanstad
Pia.Aanstad@uibk.ac.at
43-512-507-6285
University of Innsbruck
Source:Eurekalert

Related biology news :

1. Thumb-size microsystem enables cell culture and incubation
2. Gene enhancer in evolution of human opposable thumb
3. Thumbs up -- a tiny ancestral remnant lends developmental edge to humans
4. Right breakfast bread keeps blood sugar in check all day
5. Researchers set new record for brightness of quantum dots
6. UF to auction naming rights for new butterfly species online
7. Everglades phosphorus limits on the right track, but more is needed
8. UFs new owl butterfly species naming rights auctioned for $40,800
9. UMMS and CIW grant key RNAi rights to Oxford Biomedica
10. Bright lights: Mystery of glowing antibody solved by Scripps research scientists
11. Northern right whales head south to give birth, leave genetic fingerprints with NOAA researchers
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:11/30/2016)... -- higi SH llc (higi) announced today the launch ... industry thought-leaders and celebrity influencers looking to encourage, ... steps to live healthier, more active lives. ... built the largest self-screening health station network in ... have conducted over 185 million biometric screenings.  The ...
(Date:11/28/2016)... , Nov. 28, 2016 ... a rate of 16.79%" The biometric system market ... grow further in the near future. The biometric system ... billion in 2022, at a CAGR of 16.79% between ... system, integration of biometric technology in smartphones, rising use ...
(Date:11/21/2016)... Nov. 21, 2016   Neurotechnology , a ... technologies, today announced that the MegaMatcher On Card ... submitted for the NIST Minutiae Interoperability Exchange ... the mandatory steps of the evaluation protocol. ... continuing test of fingerprint templates used to establish ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... 8, 2016 Oxford ... erweitert seine Palette an anpassbaren SureSeq™ NGS-Panels mit ... Panels, das ein schnelles und kostengünstiges Studium der ... bietet eine Erkennung von Einzel-Nukleotid-Variationen (Single Nucleotide Variation, ... einzigen kleinen Panel und ermöglicht eine individuelle Anpassung ...
(Date:12/8/2016)... ... December 08, 2016 , ... Microbial genomics leader, ... uBiome is one of just six company finalists in the Health & Medicine ... uBiome, companies nominated as finalists in this year’s awards include Google, SpaceX, Oculus, ...
(Date:12/8/2016)... 8, 2016 Savannah River Remediation LLC ... selected NewTechBio,s NT-MAX Lake & Pond Sludge ... bacteria, in conjunction with Hexa Armor/ Rhombo cover ... National Pollutant Discharge Elimination System requirements. ... steady history of elevated pH levels, above 8.5, ...
(Date:12/7/2016)... McLean, VA (PRWEB) , ... December 07, 2016 ... ... peer-reviewed medical journal has concluded that “in the setting of previously treated, advanced ... Further refinement in defining the optimal patient population and timing of blood sampling ...
Breaking Biology Technology: