Why study frogs and fish? These are excellent subjects for study because during embryonic stages of development, the hearing and balance organs of both species greatly resemble those of humans. In addition, genomic sequencing of frogs and zebrafish has revealed that both species share the majority of the genes found in humans. By studying frogs and fish, whose eggs are fertilized and develop outside the mother, the scientists can address their hypotheses in living intact embryos.
Our inner ear develops in the embryo from a simple flap of skin called the otic placode into a complex, three dimensional structure that enables balance and hearing. The goal of Dr. Collazo’s zebrafish research is to understand at the molecular level, how and why otic placode cells decide to become neuronal, nonsensory or sensory cells.
“Zebrafish provide a powerful, easily maniplulated genetic system for understanding the role of specific molecules during development,” said Andres Collazo, Ph.D., House Ear Institute.
The main goal of the frog research is to determine which molecules and regions of the otic placode are required for normal patterning in the developing inner ear. These studies provide a better understanding of the causes of human inner ear malformations. Working with a team of scientists, Dr. Collazo, has discovered that physically removing either the front or back half of the otic placode in the Xenopus frog, results in a high percentage of mirror image duplicated inner ears. Mirror duplications generate a specific pattern in the wrong place, which helps in identifying which molecules are required for the normal layout of the inner ear. These studies also provide insights into some of the inner ear malformations seen in clinical patients.
Proper patterning, positioning and differentiation of the sensory organs within the inner ear are crucial for normal function in balance and hearing. Studies have found that the gene mutations in zebrafish, which can result in mirror duplicated inner ears, are found in molecules belonging to the cell signaling pathway designated Shh. Similarly, blocking the cell signaling pathway designated as Hh in the Xenopus frog or in zebrafish, results in two mirror image front halves and suggests that Shh signaling is necessary for patterning the back half. This is important because any future therapies developed for replacing lost sensory cells (hair cells) that detect motion in the inner ear, will require that the regenerated hair cells be accurately placed and positioned.
Dr. Collazo received his B.S. in Biology, at Cornell University, his Ph.D. in Zoology, University of California, Berkeley and was a postdoctoral fellow at California Institute of Technology. He has taught embryology during summer at the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts for the past 17 years.
Kirsten Holguin | Newswise Science News
Nanotubes built from protein crystals: Breakthrough in biomolecular engineering
15.11.2018 | Tokyo Institute of Technology
Insect Antibiotic Provides New Way to Eliminate Bacteria
15.11.2018 | Universität Zürich
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
15.11.2018 | Earth Sciences
15.11.2018 | Physics and Astronomy
15.11.2018 | Physics and Astronomy