Hide, WinstonKruger, Adele2023-06-022024-05-172023-06-022024-05-172009https://hdl.handle.net/10566/15291Philosophiae Doctor - PhDThe use of ontologies in the mapping of gene expression events provides an effective and comparable method to determine the expression profile of an entire genome across a large collection of experiments derived from different expression sources. In this dissertation I describe the development of the developmental human and mouse e VOC ontologies and demonstrate the ontologies by identifying genes showing a bias for developmental brain expression in human and mouse, identifying transcription factor complexes, and exploring the mouse orthologs of human cancer/testis genes. Model organisms represents fundamental aspects of mammal biology phenomena between model organism is complex and it is to be the meaningful, a simplified representation can be a powerful means for comparison illustrated here in two ways. Firstly, the ontologies have been used to illustrate methods to determine clusters of genes showing tissue-restricted expression in humans. The identification of tissue-restricted genes within an organism serves as an indication of the finetuning in the regulation of gene expression in a given tissue. Secondly, due to the differences in human and mouse gene expression on a temporal and spatial level, the ontologies were used to identify mouse orthologs of human cancer/testis genes showing cancer/testis characteristics. With the use of model systems such as mouse in the development of gene-targeted drugs in the treatment of disease, it is important to establish that the expression characteristics and profiles of a drug target in the model system is representative of the characteristics of the target in the system for which it is intended.enOntologyExpression vocabularyGene expressionCross-speciescompansonHuman developmentMouse developmentCancer/testisTranscription factorGene regulationUniversity of the Western Cape