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Departmental Seminars

Fall Semester 2017

Monday, November 13, 2017

12:00 - 1:00 PM in SSMB 138

Breathing in a Box: constraints on lung ventilation on giant pterosaurs

Dr. Jaap Hillenius, Department of Biology, College of Charleston

Pterosaurs were the first vertebrates to successfully achieve active flight, and some Cretaceous forms reached enormous size.  Fossil evidence indicates that selection for large size in these flying forms led to a light yet strong skeleton characterized by progressive fusion of many bones in the trunk.  However, this process of thoracic fusion also resulted in mechanical constraints on lung ventilation: an analysis of the joints among the vertebrae, ribs, sternum and pectoral girdles of large pterosaurs indicates limited mobility of the ribcage and sternum.  These findings are inconsistent with a previously postulated, bird-like "sternal pump" breathing mechanism.  An alternative hypothesis is proposed using a "visceral pump" mechanism that is at least consistent with the available skeletal information of these intriguing animals.

Monday, November 6, 2017

12:00 - 1:00 PM in SSMB 138

Regulation of tumor cell plasticity: a deviation from the central dogma

Dr. Simon Grelet, Department of Biochemistry, Medical University of South Carolina, Charleston, SC

Since the past few years both genomics and transcriptomics progressed at unprecedented speed and allowed significant advances in the understanding of cell and molecular biology in healthy and diseased tissues. While the gain of popularity of transcriptome-wide analyzes such as high-throughput sequencing promised quick breakthroughs in the development of antitumor therapies, their translation into major clinical advances remains plagued by drug resistance. Therefore, the classical model of genetic regulation based on a dominant role of the transcriptional regulation of gene expression does not explain each and every molecular steps driving tumor cell progression. Recent discoveries exposed additional mechanisms, often involving non-coding RNA species or RNA binding proteins regulating gene expression at the post-transcriptional level. Further investigations clearly underlined their critical contributions to tumor progression by conferring quicker and fine-tuned mechanisms to regulate cell plasticity, a feature required to develop metastasis or resistance in tumor cells.

Dr. Simon Grelet’s research aims to characterize the post-transcriptional mechanisms driving tumor cell plasticity and establish their role in the control of gene expression during tumor progression. He recently featured an intriguing mechanism, involving the regulation of alternative splicing by a RNA binding protein, that allows the synthesis from a single gene locus, of either a protein-coding mRNA or a long non-coding RNA promoting metastasis of breast and lung tumor cells.

Selected publications:

Simon Grelet, Laura A. Link, Breege Howley, Clémence Obellianne, Viswanathan Palanisamy, Vamsi K. Gangaraju, J. Alan Diehl, and Philip H. Howe. “A Regulated PNUTS mRNA to lncRNA Splice Switch Mediates EMT and Tumour Progression.” Nature Cell Biology 19, no. 9 (September 2017): 1105–15. https://doi.org/10.1038/ncb3595.

 Simon Grelet, Vanessa Andries, Myriam Polette, Christine Gilles, Katrien Staes, Anne-Pascaline Martin, Claire Kileztky, et al. “The Human NANOS3 Gene Contributes to Lung Tumour Invasion by Inducing Epithelial-Mesenchymal Transition.” The Journal of Pathology 237, no. 1 (September 2015): 25–37. https://doi.org/10.1002/path.4549.

 Simon Grelet, Ariel McShane, Renaud Geslain, and Philip H. Howe. “Pleiotropic Roles of Non-Coding RNAs in TGF-β-Mediated Epithelial-Mesenchymal Transition and Their Functions in Tumor Progression.” Cancers 9, no. 7 (July 1, 2017). https://doi.org/10.3390/cancers9070075.

Monday, October 30, 2017

12:00 - 1:00 PM in SSMB 138

A blindfolded magician walking through the storm: or how misconstrued assumptions hinder our capacity to make decisions in a critical time 

Walter A. Boeger, Universidade Federal do Paraná, Brazil

Blinded by the prevailing ideas on evolution and believing on the magic derived from misconstrued assumptions and from technology, humanity is entering a period of great environmental changes.  A new paradigm in the evolution of species associations, the Stockholm Paradigm, challenges the deeply rooted assumptions that have strongly influenced our perspective about the evolution of associations and infectious diseases. This paradigm results from the integration of accumulated knowledge and collaboration among scientists of historically independent areas of biology: parasitology and insect-plant interactions.  Recently, modeling and empirical studies, testing precepts of this paradigm, rejected some fundamental assumptions of the prevailing paradigm in the evolution of associations.  For instance, we suggest that the traditional assumptions that parasites (including pathogens) are intimately tied to their host’s lineage and, consequently, that Emergent Infectious Diseases are extremely rare are wrong.  It was misconstrued from a strict interpretation of the world around us.  Accumulated knowledge indicates that an increase in the rate of EID’s is an expected outcome associated with the environmental changes imposed by the transformation of our climate.  We, as a species, have been through major climate changes in the past and, for better or worse, we endured.  Since then, however, we have created a far more complex society, strongly dependent on technology and division of labor.  Hence, things are not as simple as in the past.  We propose that the preservation of our way of life is strongly dependent on planning, based on anticipated scenarios grounded on robust scientific knowledge – not on magical thinking.  During this talk, I will present the results of studies that support the Stockholm Paradigm.  We suggest that this paradigm should be the backbone for anticipating changes in the dynamics of EID’s associated with climatic changes that we envision for the near future.  I will also discuss aspects of other areas of interest that can benefit from this new perspective, such as conservation and agriculture.  But it is certain that any effective planning will rely on the active and intense collaboration of scientists of many areas and decision making governmental personnel. 

Cancelled - Monday, October 23, 2017

Insulin resistance and neuroplasticity

Claudia A. Grillo, Research Associate Professor, Department of Pharmacology, Physiology & Neuroscience, University of South Carolina

Monday, September 18, 2017

12:00-1:00 PM in Harbor Walk West (HWWE) 217

The Mysterious Life of Iron-Oxidizing Bacteria in Estuarine Environments

Erin Field, Assistant Professor, Department of Biology, East Carolina University

Iron-oxidizing bacteria are well-studied in high iron environments such as diffuse hydrothermal vents and freshwater iron seeps. However, we have only recently begun to explore their role in estuarine environments where reduced iron can be limiting and environmental conditions fluctuate rapidly. Recently we have found these microorganisms are widespread in estuarine sediments and can even be found in the water column where reduced iron concentrations are as low as a few micromolar. This talk will focus on the life of iron-oxidizing bacteria in these environments with emphasis on how they have adapted to life with little iron, their potential role in linking iron and sulfur biogeochemical cycles, and how this may lead to biocorrosion in estuarine environments.

 


 

 

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