> Reminder: Thesis Defense
> To: the George Mason Community
>
> *Sarah Trunnell
> Master of Science in Biology
> Molecular Biology concentration
> *
> Date: Monday July 26, 2010
> Time: 1:00 - 3:00 P.M.
> Place: Occoquan Bldg., Room 312-G
> Prince William campus
>
> Thesis Chair: Dr. Daniel N. Cox, MMB Dept.
>
> *Title:
> * "THE /DROSOPHILA /SPECTRAPLAKIN SHORT STOP DIFFERENTIALLY REGULATES 
> CLASS SPECIFIC DENDRITE MORPHOGENESIS"_//_
> *Abstract:
> *Disorders of the nervous system can often be attributed to 
> developmental abnormalities occurring during neurogenesis, which 
> affect the morphology, and ultimately functionality of neurons. In 
> order to understand how the nervous system successfully matures, it is 
> essential to uncover the molecular mechanisms governing neural 
> development.   The peripheral nervous system (PNS) of /Drosophila 
> melanogaster/, provides an excellent model system in which to 
> elucidate the molecular mechanisms governing dendrite morphogenesis.  
> Spectraplakins are an evolutionarily conserved family of cytoskeletal 
> cross-linking proteins that provide a link between the actin and 
> microtubule cytoskeletons.  Given that cytoskeletal structure and 
> organization are key mediators of neuronal shape, and by extension 
> neuronal function, understanding the molecular mechanisms underlying 
> the regulation of cytoskeletal dynamics in neurons is important to 
> achieving insight into the process of class-specific neuronal dendrite 
> morphogenesis.  To address the role of Spectraplakins in dendrite 
> morphogenesis, this thesis focuses on investigating the sole known 
> Spectraplakin gene in /Drosophila/ referred to as /short stop/ 
> (/shot/).  This research demonstrates that /shot/ exerts differential 
> effects on class specific dendrite morphogenesis of /Drosophila 
> /dendritic arborization (da) neurons of the PNS.  Comparative 
> morphological analyses reveal /shot/ is required to restrict dendritic 
> complexity among the simpler class I and II da neurons, whereas /shot 
> /is required to promote dendritic complexity among the more complex 
> class III and IV da neurons.  Taken together, these results suggest 
> dendrite morphogenesis is subject to context-dependent regulation 
> mediated via /shot/.  Immunohistochemistry analyses further reveal 
> that Shot protein is expressed in all da neurons.  Collectively, these 
> studies provide novel insight into the role of Spectraplakins in 
> dendrite development and suggest the importance of cross talk between 
> the actin and microtubule cytoskeletons in mediating neuron-specific 
> patterns of dendrite arborization.
>
> ###
> *
> All students, faculty and staff are welcome to attend*
>