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Macondo Crude Oil From The Deepwater Horizon Oil Spill Disrupts Specific Developmental Processes During Zebrafish Embryogenesis, T Yvanka De Soysa, Allison Ulrich, Timo Friedrich, Danielle Pite, Shannon L. Compton, Deborah Ok, Rebecca L. Bernardos, Gerald B. Downes, Shizuka Hsieh, Rachael Stein, M Caterina Lagdameo, Katherine Halvorsen, Lydia-Rose Kesich, Michael Jf Barresi May 2012

Macondo Crude Oil From The Deepwater Horizon Oil Spill Disrupts Specific Developmental Processes During Zebrafish Embryogenesis, T Yvanka De Soysa, Allison Ulrich, Timo Friedrich, Danielle Pite, Shannon L. Compton, Deborah Ok, Rebecca L. Bernardos, Gerald B. Downes, Shizuka Hsieh, Rachael Stein, M Caterina Lagdameo, Katherine Halvorsen, Lydia-Rose Kesich, Michael Jf Barresi

Gerald B. Downes

Background: The Deepwater Horizon disaster was the largest marine oil spill in history, and total vertical exposure of oil to the water column suggests it could impact an enormous diversity of ecosystems. The most vulnerable organisms are those encountering these pollutants during their early life stages. Water-soluble components of crude oil and specific polycyclic aromatic hydrocarbons have been shown to cause defects in cardiovascular and craniofacial development in a variety of teleost species, but the developmental origins of these defects have yet to be determined. We have adopted zebrafish, Danio rerio, as a model to test whether water accumulated fractions …


Mutation Of Zebrafish Dihydrolipoamide Branched-Chain Transacylase E2 Results In Motor Dysfunction And Models Maple Syrup Urine Disease, Timo Friedrich, Aaron M. Lambert, Mark A. Masino, Gerald B. Downes Mar 2012

Mutation Of Zebrafish Dihydrolipoamide Branched-Chain Transacylase E2 Results In Motor Dysfunction And Models Maple Syrup Urine Disease, Timo Friedrich, Aaron M. Lambert, Mark A. Masino, Gerald B. Downes

Gerald B. Downes

Analysis of zebrafish mutants that demonstrate abnormal locomotive behavior can elucidate the molecular requirements for neural network function and provide new models of human disease. Here, we show that zebrafish quetschkommode (que) mutant larvae exhibit a progressive locomotor defect that culminates in unusual nose-to-tail compressions and an inability to swim. Correspondingly, extracellular peripheral nerve recordings show that que mutants demonstrate abnormal locomotor output to the axial muscles used for swimming. Using positional cloning and candidate gene analysis, we reveal that a point mutation disrupts the gene encoding dihydrolipoamide branched-chain transacylase E2 (Dbt), a component of a mitochondrial enzyme complex, to …


Modular Laboratory Exercises To Analyze The Development Of Zebrafish Motor Behavior, Kelly Anne Mckeown, Gerald B. Downes, Lara D. Hutson Jun 2009

Modular Laboratory Exercises To Analyze The Development Of Zebrafish Motor Behavior, Kelly Anne Mckeown, Gerald B. Downes, Lara D. Hutson

Gerald B. Downes

The embryonic zebrafish is an excellent research model to examine the neural networks that coordinate locomotive behavior. It demonstrates robust locomotive behavior early in development, its nervous system is relatively simple and accessible compared to mammalian systems, and there are mutants available with specific molecular and motor deficits. We have developed a series of four exercises that provide students with a basic understanding of locomotive behavior development, nervous system organization, development of neurotransmitter responsiveness, and genetics. The first two exercises can be performed in one 3-h laboratory period, and the third and fourth exercises, which build on the first two, …


Zebrafish Bandoneon Mutants Display Behavioral Defects Due To A Mutation In The Glycine Receptor Β Subunit, Gerald B. Downes, Hiromi Hirata, Louis Saint-Amant, Wilson W. Cui, Weibin Zhou, Michael Granato, John Y. Kuwada May 2005

Zebrafish Bandoneon Mutants Display Behavioral Defects Due To A Mutation In The Glycine Receptor Β Subunit, Gerald B. Downes, Hiromi Hirata, Louis Saint-Amant, Wilson W. Cui, Weibin Zhou, Michael Granato, John Y. Kuwada

Gerald B. Downes

Bilateral alternation of muscle contractions requires reciprocal inhibition between the two sides of the hindbrain and spinal cord, and disruption of this inhibition should lead to simultaneous activation of bilateral muscles. At 1 day after fertilization, wild-type zebrafish respond to mechanosensory stimulation with multiple fast alternating trunk contractions, whereas bandoneon (beo) mutants contract trunk muscles on both sides simultaneously. Similar simultaneous contractions are observed in wild-type embryos treated with strychnine, a blocker of the inhibitory glycine receptor (GlyR). This result suggests that glycinergic synaptic transmission is defective in beo mutants. Muscle voltage recordings confirmed that muscles on both sides of …