Figure 3From: piggyBac is an effective tool for functional analysis of the Plasmodium falciparumgenomepiggyBac insertions in the genome are random but preferentially occur in 5' untranslated regions. (a) Genomic transcription units were defined to include 2 kb of 5' UTR, the coding sequence, the introns and 0.5 kb of 3' UTR, based on previous studies in Plasmodium [48, 49]. (b) Comparison of gene functions of all annotated genes in the genome (outer circle) to genes in piggyBac-inserted loci (inner circle) shows an equivalent distribution confirming random insertions in the parasite genome. (c) Comparison of stage-specific expression of all annotated genes (outer circle) to those in piggyBac-inserted loci (inner circle) validates the ability of piggyBac to insert in genes expressed in all parasite life cycle stages. (d) A comparison of piggyBac-inserted TTAA sequences to TTAA sequences randomly selected from the genome showed preferential insertion of piggyBac into 5' UTRs of genes (asterisk- χ2 test, df 1, P = 1.5 × 10-12) whereas a significantly lower number of insertions were observed in CDS and introns (double asterisks- χ2 test, df 1, P = 1.09 × 10-13).Back to article page