COMPARISON OF THE GIARDIA LAMBLIA TROPHOZOITE AND CYST TRANSCRIPTOME. Giardia duodenalis

To investigate the magnitude of the transcriptional changes occurring during the life cycle of Giardia lamblia we compared the transcriptome of trophozoites and cysts. Cysts were found to possess a much smaller transcriptome, both in terms of mRNA diversity and abundance. Genes encoding proteins related to ribosomal functions are highly over-represented. In cysts which have lost infectivity the transcriptome is further depleted. In contrast, exposure of cysts to conditions which promote excystation induced transcription. Overall design: Six cysts and three trophozoites life cycle stages were analyzed.