Transcriptome Survey of Malaria Parasite Liver Stages

To facilitate pre-eythrocytic malaria vaccine and drug target identification, a comprehensive transcriptome analysis of the parasites liver stages (LS) was undertaken. Green fluorescent protein-tagged Plasmodium yoelii (PyGFP) was used to isolate LS-infected hepatocytes from the rodent host. Genome-wide LS gene expression was profiled and compared to other parasite life cycle stages. The analysis reveals ~2000 genes active during LS development. Keywords: Stage comparison, time course 1. The study profiled gene expressions in samples from 7 stages of malaria parasite P. yoelii life cycle: a. ooSpz: Sporozoites from infected A. stephensi mosquitoes midguts (harvested 10 days after mosquito feeding) b. sgSpz: Sporozoites infected A. stephensi mosquitoes salivary glands (harvested 15 days after mosquito feeding) c. LS24: Isolated liver stage infected hepatocytes 24 hrs after in vivo infection d. LS40: Isolated liver stage infected hepatocytes 40 hrs after in vivo infection e. LS50: Isolated liver stage infected hepatocytes 50 hrs after in vivo infection f. Schz: Purified erythrocytic schizonts g. BS: mixed erythrocytic stages when parasitemia was at 5-10% 2. Samples from Liver stage parasites and Sporozoites were mainly compared to samples from mixed erythrocytic and/or schizont stage parasites with various technical replicates, including dye swaps in some comparisons.