Model Organisms in Neurodegenerative Diseases: Emphasis on Alzheimer’s and Polyglutamine Disease

Abstract

Increase in human suffering from fatal disorders like that of Parkinson’s Disease (PD), demands the need to find an effective cure for these diseases. This can be achieved through complete understanding of the origins and mechanisms of the diseases. This is, in turn facilitated by the experiments conducted on model organisms like Drosophila melanogaster, Caenorhabditis elegans and Yeast. Drosophila melanogaster’s external characters can be easily observed which can root back to the cellular and genetic alterations, Caenorhabditis elegans on the other hand having access to fully sequential genome and Yeast which can be grown easily in lab conditions with controlled metabolisms gives all these organisms an advantage to be used as a model organism.
 Firstly, Alzheimer’s Disease was discussed in detail. It is a common neurodegenerative disease having effects of cell death, irreversible dementia and malfunctioning neurons. This is due to peptides which are the major components of the amyloid plaque created by amyloid precursor protein (APP). Since Drosophila melanogaster contains similar genes dAPPl related to AD, it is used as a model organism in AD amyloidosis pathogenesis research. Secondly, polyglutamine diseases or poly Q diseases were discussed with respect to the model organisms used to study these diseases. Poly Q diseases are characterized by gene mutations leading to accumulation of insoluble proteins in regions of brain. Among nine types of poly Q diseases documented, four were discussed in detailed namely, Huntington’s disease, Kennedy disease, Spinocerebellar ataxias and Spinal muscular atrophy. Role of drosophila in the study of each type has been discussed, with respect to different manipulations done in the organism. Finally, different model organisms used to study various neurodegenerative diseases were tabulated. Also, the genes involved and the studies related to the particular gene were also represented in the form of table.