Genome-wide RIP-Chip analysis of translational repressor-bound mRNAs in the Plasmodium gametocyte

ABSTRACT: Following fertilisation, translation of stored, but previously translationally repressed transcripts, is instrumental in shaping the proteome of the early embryo of multicellular eukaryotes; further development relies on de novo transcription of the zygotic genome. A related process was evidenced in the unicellular protozoa Plasmodium berghei during transmission to the mosquito host where fertilisation and zygote development result in the formation of an entirely new cell type, the ookinete. DOZI and CITH are mRNP components that maintain mRNAs silent in the female precursor cell. In the absence of DOZI or CITH, hundreds of transcripts are destabilised, which does not block fertilization upon transmission to the mosquito host, but impairs further development of the malaria parasite. However, how many transcripts are bound by DOZI/CITH in these mRNPs and what are they remain unknown. Here, we investigated the extent of maternal contribution during post-fertilization development of P. berghei by RNA immunoprecipitation (RIP)-Chip data mining and provided further functional significance using gene tagging and gene knockout approaches. We provide conclusive evidence that in the rodent malaria parasite Plasmodium berghei 50% of the transcriptome of the female sexual precursor cell is stably associated with the translational repressors DOZI and CITH allowing morphogenesis of the zygote into the ookinete to proceed in the absence of RNA polymerase II transcription. Using in situ tagging with GFP we find for the first time novel genes that rely on translational repression on the 5' UTR. This maternal repressome provides the developing ookinete with coding potential for key molecules required during developmental progression: a near complete set of factors required for the gliding motility apparatus, but also protein trafficking, adhesins, proteases and other factors.

ORGANISM(S): Plasmodium berghei

SUBMITTER: Celine Carret 

PROVIDER: E-MTAB-2900 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress