Characterization of the Giardia intestinalis Transcriptome

Giardia gene expression is being examined using Serial Analysis of Gene Expression (SAGE) to monitor genome-wide levels of messenger RNA (mRNA) expression throughout Giardia's life cycle. Examination of genome-wide gene expression patterns will provide a coherent picture of activation and inactivation of biological pathways. This research will provide a comprehensive understanding of changes in giardial gene expression in response to important host physiological signals and will serve as a valuable model for study of other parasites and complex eukaryotes, such as yeast and animals. It will provide a dynamic framework, in the context of the life cycle, to the annotation of the Giardia genome, including the detection of unpredicted genes via detection of their tags. Keywords: Giardia, SAGE, trophozoites, encystation, excystation, cysts The Giardia SAGE project detects up- and down-regulation of genes related to giardial infection (excystation), pathogenicity (trophozoites), transmission (encystation), and survival in the environment (cysts).