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
More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy