Transcriptional analysis of in vivo Plasmodium yoelii liver stage gene expression.

The transcriptional repertoire of the in vivo liver stage of Plasmodium has remained largely unidentified and seemingly not amenable to traditional molecular analysis because of the small number of parasites and large number of uninfected hepatocytes. We have overcome this obstruction by utilizing laser capture microdissection to provide a high quality source of parasite mRNA for the construction of a liver stage cDNA library. Sequencing and annotation of this library demonstrated expression of 623 different Plasmodium yoelii genes during development in the hepatocyte. Of these genes, 25% appear to be unique to the liver stage. This is the first comprehensive analysis of in vivo gene expression undertaken for the liver stage of P. yoelii, and provides insights into the differential expression of P. yoelii genes during this critical stage of development.