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
What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
06.12.2016 | Materials Sciences
06.12.2016 | Medical Engineering
06.12.2016 | Power and Electrical Engineering