Transcriptional silencing and activation of paternal DNA during Plasmodium berghei zygotic development and transformation to oocyst.
The malaria parasite develops sexually in the mosquito midgut upon entry with the ingested blood meal before it can invade the midgut epithelium and embark on sporogony. Recent data have identified a number of distinct transcriptional programmes operating during this critical phase of the parasite life cycle. We aimed at characterizing the parental contribution to these transcriptional programmes and establish the genetic framework that would guide further studies of Plasmodium zygotic development and ookinete-to-oocyst transition. To achieve this we used in vitro and in vivo cross-fertilization experiments of various parasite lines expressing fluorescent reporters under the control of constitutive and stage-specific promoters. The results revealed that the zygote/ookinete stage exhibits a maternal phenotype with respect to constitutively expressed reporters, which is derived from either maternal mRNA inheritance or transcription of the maternal allele. The respective paternal alleles are silenced in the zygote/ookinete but reactivated after midgut invasion and transformation to oocyst. Transcripts specifically produced in the zygote/ookinete are synthesized de novo by both parental alleles. These findings highlight a putative role of epigenetic regulation of Plasmodium zygotic development and add substantially to the emerging picture of the molecular mechanisms regulating this important stage of malaria transmission.
Department of Life Sciences, Imperial College London, London, UK.
Chiamaka V
CV
Ukegbu
Department of Life Sciences, Imperial College London, London, UK.
Jee-Sun
JS
Cho
Department of Life Sciences, Imperial College London, London, UK.|The Cyprus Institute, Nicosia, Cyprus.
George K
GK
Christophides
Department of Life Sciences, Imperial College London, London, UK.|The Cyprus Institute, Nicosia, Cyprus.
Dina
D
Vlachou
D019677:Artificial Gene Fusion; D016054:DNA, Protozoan / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D017125:Genes, Protozoan; D017930:Genes, Reporter; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics; D033661:Oocysts; D010962:Plasmodium berghei / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D016054:DNA, Protozoan; D008164:Luminescent Proteins