Project description:In the parasitic wasp Venturia canescens sexual and asexual populations coexist in sympatry and showed distinct foraging behaviours. By sequencing head transcriptome from sexual and asexual population, we assess transcriptomic divergence between the 2 populations.
Project description:We aimed at characterizing the diverse hemocyte populations present in the hemolymph of the Drosophila larvae. The hemocytes were collected from wandering larvae infested by wasp (WI) or not infested (NI). The hemocytes were then sequenced using 10x genomics technology.
Project description:Malaria transmission requires the conversion of some asexual parasites into sexual forms termed gametocytes. The initial stages of sexual development, including sexually-committed schizonts and sexual rings, remain poorly characterized, in part because only a subset of parasites undergo sexual development and they are morphologically identical to their asexual counterparts. Here we present a system based on conditional expression of PfAP2-G, the master regulator of sexual conversion, for controlled sexual induction. Induction resulted in ~90% sexual conversion, which enables the characterization of early sexual stages without further purification. Transcriptomic analysis identified the alterations that follow pfap2-g activation, including identification of genes that are down-regulated. We also show that the inducible system enables the characterization of committed stages at the phenotypic level. Altogether, the inducible lines will facilitate the study of the initial stages of sexual development, which is important for the development of new strategies to stop malaria transmission.
Project description:The asexual forms of the malaria parasite Plasmodium falciparum are uniquely adapted for chronic persistence in human red blood cells, continuously evading the immune system using an epigenetically regulated process. However, parasite survival on a population level also requires transmission of sexual parasite forms to subsequent human hosts. Here, we reveal that the essential nuclear gene, P. falciparum histone deacetylase 2 (PfHda2), silences specific subsets of genes involved in antigenic variation or conversion to sexual stages.
Project description:Genome-wide analysis of DNA methylation for asexual and sexual stages of Cordyceps militaris DNA methylation is a basic epigenetic mechanism found in eukaryotes, but its patterns and roles vary significantly among diverse taxa. In fungi, DNA methylation has various effects on diverse biological processes; however, its function underlying the sexual development of fungi remains unclear. Cordyceps militaris, readily performing sexual reproduction, provides a remarkably rich model for understanding epigenetic processes in sexual development. The methylome was surveyed to assess DNA methylation patterns of the nascent fruiting body in C. militaris at single-base resolution by genomic bisulfite sequencing (BS-Seq). The results showed that around 0.4 % of cytosines are methylated, and that there is no difference compared with the DNA methylation level (0.39 %) during asexual development. However, 225 differentially methylated regions (DMRs) were identified between the stages. Moreover, RNA-Seq analysis indicated that the DMRs have no direct relation with the genes for fungal sexual development in C. militaris. DNA methylation regions from the BS-Seq show a striking correspondence to regions predicted to be repetitive and repeat-induced point mutation (RIP) mutated, suggesting that DNA methylation functions as a genome defense mechanism in sexual development. These results provide a comprehensive characterization of DNA methylation in the sexual development of C. militaris, which will contribute to future investigations of epigenetics in fungi. Bisulphite converted genomic DNA from the mycelium and fruitingbody of Cordyceps militaris
Project description:During intra-erythrocytic development, late asexually replicating Plasmodium falciparum parasites sequester from peripheral circulation. This facilitates chronic infection and is linked to severe disease and organ-specific pathology including cerebral and placental malaria. Immature gametocytes M-bM-^@M-^S sexual stage precursor cells M-bM-^@M-^S likewise disappear from circulation. Recent work has demonstrated that these sexual stage parasites are located in the hematopoietic system of the bone marrow before mature gametocytes are released into the blood stream to facilitate mosquito transmission. However, as sequestration occurs only in vivo and not during in vitro culture, the mechanisms by which it is regulated and enacted (particularly by the gametocyte stage) remain poorly understood. We generated the most comprehensive P. falciparum functional gene network to date by integrating global transcriptional data from a large set of asexual and sexual in vitro samples, patient-derived in vivo samples, and a new set of in vitro samples profiling sexual commitment. We defined more than 250 functional modules (clusters) of genes that are co-expressed primarily during the intra-erythrocytic parasite cycle, including 35 during sexual commitment and gametocyte development. Comparing the in vivo and in vitro datasets allowed us, for the first time, to map the time point of asexual parasite sequestration in patients to 22 hours post invasion, confirming previous in vitro observations on the dynamics of host cell modification and cytoadherence. Moreover, we were able to define the properties of gametocyte sequestration, demonstrating the presence of two circulating gametocyte populations: gametocyte rings between 0 and ~30 hours post invasion and mature gametocytes after around 7 days post invasion. We used 164/TdTom, a transgenic parasite line expressing a red fluorescent protein reporter under a gametocyte-specific promoter to generate schizont samples. Schizonts were subsequently isolated from both the fluorescent and non-fluorescent population by FACS and prepared for microarray analysis. Two biological replicates were produced for both the fluorescent and the non-fluorescent samples.
Project description:Prediction of the antimalarial potential of small molecules using data from various chemical libraries that were screened against the asexual and sexual (gametocyte) stages of the parasite. Several compounds’ molecular fingerprints were used to train machine learning models to recognize stage-specific active and inactive compounds.
Implementation of this model code by Ersilia is available here:
https://github.com/ersilia-os/eos80ch
Project description:The asexual forms of the malaria parasite Plasmodium falciparum are uniquely adapted for chronic persistence in human red blood cells, continuously evading the immune system using an epigenetically regulated process. However, parasite survival on a population level also requires transmission of sexual parasite forms to subsequent human hosts. Here, we reveal that the essential nuclear gene, P. falciparum histone deacetylase 2 (PfHda2), silences specific subsets of genes involved in antigenic variation or conversion to sexual stages. Two parallel timecourses resulting in a total of 22 samples (11 wildtype, 11 PfHda2 knockdown) were hybridized against a Cy3-labeled reference pool of 3D7 mixed stage parasites on a two-color array.
Project description:Investigation of differences in gene expression between two strains of the planarian Schmidtea mediterranea. The sexual strain are cross-fertilizing hermaphrodites with reproductive organs that develop post-embryonically and the asexual strain reproduces exclusively by transverse fission and fail to develop reproductive organs. A two chip study using total RNA recovered from asexual and sexual animals. Each chip measures the expression level of 16,797 ESTs from S. mediterranea with 10 60-mer probe pairs (PM/MM) per gene, with two-fold technical redundancy.