Project description:Plasmodium falciparum gametocytes undergo 14 days of gametocytogenesis to generate mature, transmissible gametocytes. This timecourse delineates the transcriptional profiles of gametocytes from commitment to maturity.
Project description:The Plasmodium sexual gametocyte stages are the only transmissible form of the malaria parasite and are thus responsible for the continued transmission of the disease. Gametocytes undergo extensive functional and morphological changes from commitment to maturity, directed by an equally extensive control program. Several interconnected mechanisms governing sexual commitment have been described. However, the processes that drive the subsequent differentiation and development of the gametocyte remain largely unexplored. Using chromatin immunoprecipitation followed by high-throughput sequencing we map the genome-wide occupancy of H3K36me2 and H3K36me3 during early gametocyte development and describe an association between these histone modifications and the global changes in the transcriptional program driving gametocyte development post-commitment.
Project description:In order to assess what PyNOT1-G contributes to Plasmodium gametocyte commitment and maturation, we conducted comparative RNA-seq on enriched schizonts and gametocytes. We identified many transcripts that are dysregulated in accordance with the gene deletion phenotype.
Project description:Differentiation from asexual blood stages to sexual gametocytes is required for transmission of malaria parasites from the human host to mosquitos, where sexual fertilization occurs to complete the lifecycle. Although preventing gametocyte development would block parasite transmission, the molecular mechanisms underlying sexual commitment and gametocyte maturation are still relatively unknown. Previous studies identified an ApiAP2 protein, AP2-G2, which plays a critical role in gametocyte maturation in rodent malaria parasite Plasmodium berghei by acting as the repressor of asexual stage genes in gametocytes. In this work we characterize the P. falciparum orthologue (PF3D7_1408200) of PbAP2-G2 and report that it plays a critical role in maturation of gametocytes. Disruption of pfap2-g2 did not obstruct commitment to sexual development but the majority of parasites were unable to develop normally beyond stage III gametocytes. In asexual stages PfAP2-G2 binds to the promoters of wide variety of genes expressed in diverse range of parasite’s life cycle stages including gametocytes, mosquito lifecycle stages early ring stage genes and genes encoding for proteins involved in egress and invasion. Surprisingly, we also identify binding of PfAP2-G2 in the gene body of almost 3000 genes. We could also show that PfAP2-G2 interacts with chromatin remodeling proteins and another ApiAP2 protein (PF3D7_1139300) whose motif is also overrepresented in the ChIP-seq data. Overall this work suggests that PfAP2-G2 is a transcriptional regulator that regulates genes possibly by recruiting additional transcription factors and chromatin remodeling machinery and plays a critical role in the development of malaria parasites as they transition from the asexual stage to gametocytes.
Project description:Differentiation from asexual blood stages to sexual gametocytes is required for transmission of malaria parasites from the human to the mosquito host. Preventing gametocyte commitment and development would block parasite transmission, but the underlying molecular mechanisms behind these processes remain poorly understood. Here, we report that the ApiAP2 transcription factor, PfAP2-G2 (PF3D7_1408200) plays a critical role in the maturation of Plasmodium falciparum gametocytes. PfAP2-G2 binds to the promoters of a wide array of genes that are expressed at many stages of the parasite life cycle. Interestingly, we also find binding of PfAP2-G2 within the gene body of almost 3000 genes, which strongly correlates with the location of H3K36me3 and several other histone modifications as well as Heterochromatin Protein 1 (HP1), suggesting that occupancy of PfAP2-G2 in gene bodies may serve as an alternative regulatory mechanism. Disruption of pfap2-g2 does not impact asexual development, parasite multiplication rate, or commitment to sexual development but the majority of sexual parasites are unable to mature beyond stage III gametocytes. The absence of pfap2-g2 leads to overexpression of 28% of the genes bound by PfAP2-G2 and none of the PfAP2-g2 bound are downregulated, suggesting that it is a repressor. We also find that PfAP2-G2 interacts with chromatin remodeling proteins, a microrchidia (MORC) protein, and another ApiAP2 protein (PF3D7_1139300). Overall our data demonstrate that PfAP2-G2 is an important transcription factor that establishes an essential gametocyte maturation program in association with other chromatin-related proteins.
Project description:The P.falciparum gametocyte proteomes of wild type gametocytes and two clones of Pfg377 depleted gametocytes were obtained for a label free comparative analysis to identify osmiophilic body proteins. Gametocyte samples were analyzed by LC-MS/MS and processed by MaxQuant for identification and LFQ quantification.
Project description:Purpose: To carryout comparative transcriptomics between the ZNF4-K0 and the wild type in the ring and mature gametocyte stage of Plasmodium falciparum Methods: Total RNA was isolated from ring stage and percoll- enriched mature (stage V) gametocytes from the ZNF4-KO and NF54 wildtype using the Trizol reagent (Invitrogen) according to the manufacturer’s protocol. . RNA sequencing was performed at the Genomic Facility of the University Clinic at the RWTH University Aachen, Germany. Briefly, the quality of the isolated total RNA samples from ring stage and mature gametocytes of the ZNF4-KO and the wildtype were evaluated by Tapestation 4200 (Agilent). Libraries were generated with TruSeq Stranded mRNA Library Preparation kit (Illumina) from high quality total RNA samples according to the manufacturer´s protocol. The generated libraries, which pass the QC check on Tapestation 4200 (Agilent) were sequenced on a NextSeq 500 (Illumina) with High output Kit v2.5 (150 cycles) for paired-end sequencing according to standard procedure provided by Illumina. Results:Comparative transcriptomics between wildtype and ZNF4-KO in ring and mature gametocyte stages show only 66 genes de-regulated by greater than 2-fold in the ZNF4-KO ring stage while about 473 (274- upregulated and 199 down-regulated) were deregulated in mature gametocytes. Conclusions: Our combine data therefore reveal that ZNF4 plays an important role in male gametocyte exflagellation through the regulation of male gametocyte genes