RESTRICTION checkpoint controls bradyzoite development in Toxoplasma gondii
Ontology highlight
ABSTRACT:
ORGANISM(S): Toxoplasma gondii
PROVIDER: GSE200962 | GEO | 2022/04/23
REPOSITORIES: GEO
Similar Datasets
Project description:Although apicomplexans lack conventional R-point regulators, presence of the quiescent G1 forms of 43 parasites, including mature T. gondii bradyzoites suggests that a functional RESTRICTION checkpoint 44 exists in apicomplexan parasites. We showed that Cdk-related G1 kinase TgCrk2 forms alternative 45 complexes with atypical cyclins (TgCycP1, TgCycP2 and TgCyc5) in the rapidly dividing developmentally 46 incompetent RH and slower dividing developmentally competent ME49 tachyzoites and bradyzoites. 47 Examination of individual cyclins verified the correlation of cyclin expression with growth dependence and 48 development capacity of type I RH and type II ME49 strains. We demonstrated that rapidly dividing RH 49 tachyzoites are dependent on TgCycP1 and expression of TgCycP1 interferes with bradyzoite 50 differentiation. By using an auxin-induced degradation (AID) model, we established that TgCycP2 51 regulates G1 duration in the developmentally competent ME49 tachyzoites but not in the developmentally 52 incompetent RH tachyzoites. We also tested the functions of TgCycP2 and TgCyc5 in alkaline induced in 53 vitro model and in ex vivo model of spontaneous bradyzoite differentiation (rat embryonic brain cells). 54 Based on functional and global gene expression analyses, we determined that TgCycP2 also regulates 55 bradyzoite replication, while stress- or host-induced TgCyc5 was critical for efficient bradyzoite conversion 56 and tissue cyst maturation.
2022-08-12 | PXD033109 | Pride
Project description:Two forms of the protozoan parasite Toxoplasma gondii are associated with intermediate hosts such as humans: rapidly growing tachyzoites are responsible for acute illness, whereas slowly dividing encysted bradyzoites can remain latent within the tissues for the life of the host. In order to identify genetic factors associated with parasite differentiation, we have used a strong bradyzoite-specific promoter (identified by promoter trapping) to drive the expression of T. gondii hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) in stable transgenic parasites, providing a stage-specific positive/negative selectable marker. Insertional mutagenesis has been carried out on this parental line, followed by bradyzoite induction in vitro and selection in 6-thioxanthine to identify misregulation mutants. Two different mutants fail to induce the HXGPRT gene efficiently during bradyzoite differentiation. These mutants are also defective in other aspects of differentiation: they replicate well under bradyzoite growth conditions, lysing the host cell monolayer as effectively as tachyzoites. Expression of the major bradyzoite antigen BAG1 is reduced, and staining with Dolichos biflorus lectin shows reduced cyst wall formation. Microarray hybridizations show that these mutants behave more like tachyzoites at a global level, even under bradyzoite differentiation conditions.
2005-07-21 | E-SMDB-1406 | biostudies-arrayexpress
Project description:Two forms of the protozoan parasite Toxoplasma gondii are associated with intermediate hosts such as humans: rapidly growing tachyzoites are responsible for acute illness, whereas slowly dividing encysted bradyzoites can remain latent within the tissues for the life of the host. In order to identify genetic factors associated with parasite differentiation, we have used a strong bradyzoite-specific promoter (identified by promoter trapping) to drive the expression of T. gondii hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) in stable transgenic parasites, providing a stage-specific positive/negative selectable marker. Insertional mutagenesis has been carried out on this parental line, followed by bradyzoite induction in vitro and selection in 6-thioxanthine to identify misregulation mutants. Two different mutants fail to induce the HXGPRT gene efficiently during bradyzoite differentiation. These mutants are also defective in other aspects of differentiation: they replicate well under bradyzoite growth conditions, lysing the host cell monolayer as effectively as tachyzoites. Expression of the major bradyzoite antigen BAG1 is reduced, and staining with Dolichos biflorus lectin shows reduced cyst wall formation. Microarray hybridizations show that these mutants behave more like tachyzoites at a global level, even under bradyzoite differentiation conditions. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. User Defined
2005-08-13 | E-GEOD-3119 | biostudies-arrayexpress
Project description:Somatic cells surrounding the oocyte were sampled at the following stages: developmentally incompetent or poorly competent prophase I oocytes (NC1 oocytes), developmentally competent prophase I oocytes (C1 oocytes), and developmentally competent metaphase II oocytes (C2 oocytes). NC1 samples were collected from late vitellogenic females (LV), C1 samples from post-vitellogenic females (PV), and C2 samples from females undergoing meiotic maturation (Germinal Vesicle Breakdown) Global transcriptional profiling was performed using somatic cells collected from rainbow trout ovarian follicles during in vivo oocyte developmental competence acquisition. Somatic cells were collected at 3 stages of oogenesis: NC1 stage follicles (LV, late vitellogenic, prophase I arrested oocytes, meiotically incompetent and developmentally incompetent, n=6), C1 stage follicles (PV, post-vitellogenic, prophase I arrested oocytes, meiotically competent and developmentally competent, n=16). Ovulatory follicles were also collected during oocyte maturation after in vivo induction (metaphase II arrested oocytes, developmentally fully competent, n=6).
2012-10-14 | E-GEOD-36602 | biostudies-arrayexpress
Project description:Two forms of the protozoan parasite Toxoplasma gondii are associated with intermediate hosts such as humans: rapidly growing tachyzoites are responsible for acute illness, whereas slowly dividing encysted bradyzoites can remain latent within the tissues for the life of the host. In order to identify genetic factors associated with parasite differentiation, we have used a strong bradyzoite-specific promoter (identified by promoter trapping) to drive the expression of T. gondii hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) in stable transgenic parasites, providing a stage-specific positive/negative selectable marker. Insertional mutagenesis has been carried out on this parental line, followed by bradyzoite induction in vitro and selection in 6-thioxanthine to identify misregulation mutants. Two different mutants fail to induce the HXGPRT gene efficiently during bradyzoite differentiation. These mutants are also defective in other aspects of differentiation: they replicate well under bradyzoite growth conditions, lysing the host cell monolayer as effectively as tachyzoites. Expression of the major bradyzoite antigen BAG1 is reduced, and staining with Dolichos biflorus lectin shows reduced cyst wall formation. Microarray hybridizations show that these mutants behave more like tachyzoites at a global level, even under bradyzoite differentiation conditions. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-08-13 | GSE3119 | GEO
Project description:Using high through-put RNA sequencing, we assayed the transcriptomes of three different strains of Toxoplasma gondii representing three common genotypes under both in vitro tachyzoite and in vitro bradyzoite-inducing alkaline stress culture conditions. Strikingly, the differences in transcriptional profiles between the strains, RH, PLK, and CTG, is much greater than differences between tachyzoites and alkaline stressed in vitro bradyzoites. With an FDR of 10%, we identify 241 genes differentially expressed between CTG tachyzoites and in vitro bradyzoites, including 5 putative AP2 transcription factors. We also observe close association between cell cycle regulated genes and differentiation. By Gene Set Enrichment Analysis (GSEA), there are a number of KEGG pathways associated with the in vitro bradyzoite transcriptomes of PLK and CTG, including pyrimidine metabolism and DNA replication. These functions are likely associated with cell-cycle arrest. When comparing mRNA levels between strains, we identify 1,526 genes that are differentially expressed regardless of culture-condition as well as 846 differentially expressed only in bradyzoites and 542 differentially expressed only in tachyzoites between at least two strains. Using GSEA, we identify ribosomal proteins as being expressed at significantly higher levels in the CTG strain than in either the RH or PLK strains. This association holds true regardless of life cycle stage. Type I M-bM-^@M-^S RH, Type II M-bM-^@M-^S PLK, and Type III CTG parasites were each grown in either alkaline, bradyzoite conditions or pH neutral, tachyzoites conditions. 6 conditions, 3 replicates each, 18 total samples
2014-09-01 | E-GEOD-60305 | biostudies-arrayexpress
Project description:Somatic cells surrounding the oocyte were sampled at the following stages: developmentally incompetent or poorly competent prophase I oocytes (NC1 oocytes), developmentally competent prophase I oocytes (C1 oocytes), and developmentally competent metaphase II oocytes (C2 oocytes). NC1 cumulus cells (CC) were sampled from immature calf oocytes, C1 samples from immature cow oocytes, and C2 samples from in vivo matured cow oocytes. Global transcriptional profiling was performed using cumulus cells collected from bovine ovarian follicles during in vivo oocyte developmental competence acquisition. Cumulus cells were collected at 3 stages: early stage follicles (prophase I arrested oocytes, meiotically competent but developmentally incompetent, n=6), late stage follicles (prophase I arrested oocytes, meiotically competent and developmentally competent, n=6) and ovulatory follicles collected by ovum pick-up (OPU) in vivo (metaphase II arrested oocytes, developmentally fully competent, n=5).
2012-10-14 | E-GEOD-36605 | biostudies-arrayexpress
Project description:Microarray analysis of gene expression in 2-cell embryos obtained from developmentally competent MII oocytes or developmentally incompetent MII (NSN) oocytes. In this study we have compared the expression profile of 2-cell embryos obtained after following in vitro fertilisation of developmentally competent (control) or incompetent (NSN) MII oocytes with the aim of identifying the gene expression networks that operate at this specific stage of development.
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Project description:Somatic cells surrounding the oocyte were sampled at the following stages: developmentally incompetent or poorly competent prophase I oocytes (NC1 oocytes), developmentally competent prophase I oocytes (C1 oocytes), and developmentally competent metaphase II oocytes (C2 oocytes). NC1 samples were collected from immature stage IV follicles, C1 samples from immature stage VI follicles, and C2 samples from in vitro matured stage VI follicles. Global transcriptional profiling was performed using somatic cells collected from xenopus ovarian follicles during in vivo oocyte developmental competence acquisition. Somatic cells were collected at 3 stages of oogenesis: early stage follicles (stage IV, vitellogenic, prophase I arrested oocytes, meiotically competent but developmentally incompetent, n=5), late stage follicles (stage VI, post-vitellogenic, prophase I arrested oocytes, meiotically competent and developmentally competent, n=5) and ovulatory follicles collected after in vitro maturation induction with hCG of post-vitellogenic follicles (metaphase II arrested oocytes, developmentally fully competent, n=5).
2012-10-14 | E-GEOD-36603 | biostudies-arrayexpress
Project description:Cumulus cells surrounding the oocyte were sampled at the following stages: developmentally incompetent or poorly competent prophase I oocytes (NC1 oocytes), developmentally competent prophase I oocytes (C1 oocytes), and developmentally competent metaphase II oocytes (C2 oocytes). NC1 samples were collected from immature, unexpanded cumulus-oocytes complexes (COC) from prepubertal (3-week-old) mice, C1 samples from immature, unexpanded cumulus-oocytes complexes (COC) from adult (8-week-old) and C2 samples from mature, expanded COCs obtained from the oviduct from 8-week-old mice after standard superovulation protocol. Global transcriptional profiling was performed using cumulus cells collected from murine ovarian follicles during in vivo oocyte developmental competence acquisition. Cumulus cells were collected at 3 stages: early stage follicles (prophase I arrested oocytes, meiotically competent but developmentally incompetent, n=5), late stage follicles (prophase I arrested oocytes, meiotically competent and developmentally competent, n=5) and ovulatory follicles collected in vivo (metaphase II arrested oocytes, developmentally fully competent, n=5).
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