Articles by Laura A. Berkowitz in JoVE
Application of a C. elegans Dopamine Neuron Degeneration Assay for the Validation of Potential Parkinson's Disease Genes Laura A. Berkowitz1, Shusei Hamamichi1, Adam L. Knight1, Adam J. Harrington1, Guy A. Caldwell1, Kim A. Caldwell1 1Department of Biological Sciences, University of Alabama This video demonstrates how to use C. elegans to assess dopaminergic neuron neurodegeneration as a model for Parkinson's disease. Furthermore, genetic screens are used to identify factors that either enhance degeneration or are neuroprotective.
Generation of Stable Transgenic C. elegans Using Microinjection Laura A. Berkowitz1, Adam L. Knight1, Guy A. Caldwell1, Kim A. Caldwell1 1Department of Biological Sciences, University of Alabama This video demonstrates the technique of microinjection into the gonad of C. elegans to create transgenic animals.
Other articles by Laura A. Berkowitz on PubMed
SRC-1 and Wnt Signaling Act Together to Specify Endoderm and to Control Cleavage Orientation in Early C. Elegans Embryos Developmental Cell. Jul, 2002 | Pubmed ID: 12110172 In early C. elegans embryos, signaling between a posterior blastomere, P2, and a ventral blastomere, EMS, specifies endoderm and orients the division axis of the EMS cell. Although Wnt signaling contributes to this polarizing interaction, no mutants identified to date abolish P2/EMS signaling. Here, we show that two tyrosine kinase-related genes, src-1 and mes-1, are required for the accumulation of phosphotyrosine between P2 and EMS. Moreover, src-1 and mes-1 mutants strongly enhance endoderm and EMS spindle rotation defects associated with Wnt pathway mutants. SRC-1 and MES-1 signal bidirectionally to control cell fate and division orientation in both EMS and P2. Our findings suggest that Wnt and Src signaling function in parallel to control developmental outcomes within a single responding cell.
The Early-onset Torsion Dystonia-associated Protein, TorsinA, is a Homeostatic Regulator of Endoplasmic Reticulum Stress Response Human Molecular Genetics. Sep, 2010 | Pubmed ID: 20584926 Early-onset torsion dystonia is the most severe heritable form of dystonia, a human movement disorder that typically starts during a developmental window in early adolescence. Deletion in the DYT1 gene, encoding the torsinA protein, is responsible for this dominantly inherited disorder, which is non-degenerative and exhibits reduced penetrance among carriers. Here, we explore the hypothesis that deficits in torsinA function result in an increased vulnerability to stress associated with protein folding and processing in the endoplasmic reticulum (ER), where torsinA is located. Using an in vivo quantitative readout for the ER stress response, we evaluated the consequences of torsinA mutations in transgenic nematodes expressing variants of human torsinA. This analysis revealed that, normally, torsinA serves a protective function to maintain a homeostatic threshold against ER stress. Furthermore, we show that the buffering capacity of torsinA is greatly diminished by the DYT1-associated deletion or mutations that prevent its translocation to the ER, block ATPase activity, or increase the levels of torsinA in the nuclear envelope versus ER. Combinations of transgenic Caenorhabditis elegans designed to mimic clinically relevant genetic modifiers of disease susceptibility also exhibit a direct functional correlation to changes in the ER stress response. Furthermore, using mouse embryonic fibroblasts (MEFs) from torsinA knockout mice, we demonstrated that loss of endogenous torsinA results in enhanced sensitivity to ER stress. This study extends our understanding of molecular mechanisms underlying dystonia, and establishes a new functional paradigm to evaluate therapeutic strategies to compensate for reduced torsinA activity in the ER as a means to restore homeostatic balance and neuronal function.