Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Embryology Study Offers Clues to Birth Defects

12.06.2009
Gregg Duester, Ph.D., professor of developmental biology at Burnham Institute for Medical Research (Burnham), along with Xianling Zhao, Ph.D., and colleagues, have clarified the role that retinoic acid plays in limb development.

The study showed that retinoic acid controls the development (or budding) of forelimbs, but not hindlimbs, and that retinoic acid is not responsible for patterning (or differentiation of the parts) of limbs. This research corrects longstanding misconceptions about limb development and provides new insights into congenital limb defects. The study was published online in the journal Current Biology on May 21.

In studies of mice and zebrafish, the team found that retinoic acid suppresses the gene fibroblast growth factor 8 (Fgf8) during the period when forelimb budding occurs, creating a suitable environment for the creation of forelimb buds.

“For decades, it was thought that retinoic acid controlled limb patterning, such as defining the thumb as being different from the little finger,” said Dr. Duester. “However, we have demonstrated in mice that retinoic acid is not required for limb patterning, but rather is necessary to initiate the limb budding process. We also found that retinoic acid was unnecessary for hindlimb (leg) budding, but was needed for forelimb (arm) budding.”

Congenital birth defects of the arms, legs, hands or feet result from improper development of limb bud tissues during embryogenesis. These processes are regulated by signaling molecules that control the growth and differentiation of progenitor cells by regulating specific genes. One of these signaling molecules is retinoic acid, a metabolite produced from vitamin A (retinol), which plays a key role in the development of limbs and other organs. Dr. Duester's lab was instrumental in identifying Raldh2 and Raldh3, the genes responsible for retinoic acid synthesis, and has shown that retinoic acid is only produced by certain cells at precise stages of development.

In the study, the team of scientists showed that mice missing the Raldh2 and Raldh3 genes, which normally die early and do not develop limbs, could be rescued by treatment with a small dose of retinoic acid. However, forelimb development was stunted, suggesting that retinoic acid is required for forelimb but not hindlimb development. In zebrafish, the forelimb (pectoral fin) is also missing in retinoic acid-deficient embryos, but they were able to rescue fin development by treating such embryos with a drug that reduces fibroblast growth factor activity, thus supporting the hypothesis that retinoic acid normally reduces this activity.

By providing a more complete understanding of the molecular mechanisms involved in normal limb development, these findings may lead to new therapeutic or preventative measures to combat congenital limb defects, such as Holt-Oram syndrome, a birth defect characterized by upper limb and heart defects.

About Burnham Institute for Medical Research
Burnham Institute for Medical Research is dedicated to revealing the fundamental molecular causes of disease and devising the innovative therapies of tomorrow. Burnham, with operations in California and Florida, is one of the fastest-growing research institutes in the country. The Institute ranks among the top-four institutions nationally for NIH grant funding and among the top-25 organizations worldwide for its research impact. Burnham utilizes a unique, collaborative approach to medical research and has established major research programs in cancer, neurodegeneration, diabetes, infectious and inflammatory and childhood diseases. The Institute is known for its world-class capabilities in stem cell research and drug discovery technologies. Burnham is a nonprofit, public benefit corporation.

Josh Baxt | Newswise Science News
Further information:
http://www.burnham.org

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>