By creating a genetic mutation in zebrafish, University of Oregon scientists say they've discovered a previously unknown mechanism for cleft palate, a common birth defect in humans that has challenged medical professionals for centuries.
Many molecular pathways in zebrafish are present in humans and other vertebrates. By studying the induced mutation in zebrafish, the 10-member research team isolated a disruption in early developmental signaling involving Pdgf, a platelet-derived growth-factor protein, and a microRNA known as Mirn140, the researchers write in a paper posted online in advance of regular publication the monthly journal Nature Genetics.
Mutant zebrafish lacking Pdgf had cleft palate similar to many human babies, showing that this growth factor helps to organize cells that make the palate. It came as a surprise that zebrafish into which the investigators had injected too much Mirn140 also had cleft palate.
MicroRNAs are small gene products, found to be involved in gene expression, that were first described in 1993 by researchers at Harvard University. The term microRNA was introduced in when these single-strand RNA molecules about nucleotides in length were more fully detailed in Science in October 2001 by Gary Ruvkun of Massachusetts General Hospital in Boston.
Mirn140, when operating normally, allows for normal cell signaling by the Pdgfra protein that properly triggers cell migrations necessary for correct oral-cranial building. The researchers showed that Mirn140 blocks the cellâ€™s expression of Pdgfra. Thus, cleft palate can result from too little Pdgfra that occurs because of either a mutation in the Pdgfra gene or too much Mirn140."We showed that this microRNA regulates the expression of the gene by controlling the migration of precursor cells to the palate-forming area," said principal investigator John H. Postlethwait, a professor of biology and member of the UO's Institute of Molecular Biology and Institute of Neuroscience. "This is a novel mechanism never before described."
The first known attempt to correct the defect occurred in 500 A.D. The defect occurs with or without cleft lip (a separation of the two sides of the lip), on average, in 1 in 600 newborns, according to the Cleft Palate Foundation, but can vary by race. The highest incidence (3.6 per 1,000 births) occurs in American Indians. Palate formation begins after five weeks of gestation in humans and defects can become visible at 17 weeks, according to WebMDâ€™s eMedicine.
The findings provide a new window into the mechanisms involved in cleft palate and craniofacial defects, but researchers caution that the findings don't point toward new clinical applications.
"Further exploration of how microRNAs and other factors modulate signaling pathways such as the Pdgf pathway during palatogenesis will assuredly continue to provide insights into the cause of, and possible treatments for, human craniofacial disease," the authors conclude.
Co-authors of the Nature Genetics paper with Postlethwait were: postdoctoral researcher Johann K. Eberhart; graduate students Xinjun He and Hao Song; research assistant Mary E. Swartz; research associate Yi-Lin Yan; undergraduate students Taylor C. Boling and Allison K. Kunerth; former graduate student Macie B. Walker; and Charles B. Kimmel, professor emeritus of biology. Eberhart and He were team leaders on the project, but all co-authors contributed equally.
The U.S. National Institutes of Health and U.S. National Center for Research Resources funded the research through grants to Postlethwait, Eberhart and Kimmel.
About the University of Oregon
The University of Oregon is a world-class teaching and research institution and Oregon's flagship public university. The UO is a member of the Association of American Universities (AAU), an organization made up of 62 of the leading public and private research institutions in the United States and Canada. Membership in the AAU is by invitation only. The University of Oregon is one of only two AAU members in the Pacific Northwest.
Jim Barlow | EurekAlert!
Small but versatile; key players in the marine nitrogen cycle can utilize cyanate and urea
10.12.2018 | Max-Planck-Institut für Marine Mikrobiologie
Carnegie Mellon researchers probe hydrogen bonds using new technique
10.12.2018 | Carnegie Mellon University
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals
Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.
Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.
Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...
Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.
The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.
10.12.2018 | Event News
06.12.2018 | Event News
03.12.2018 | Event News
10.12.2018 | Life Sciences
10.12.2018 | Physics and Astronomy
10.12.2018 | Life Sciences