Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Transcriptome analysis of oocyst, tachyzoite, and bradyzoite development in the type II Toxoplasma gondii strain M4.

ABSTRACT: There were three primary objectives to the overall experiment. I. Describe the transcriptome of the oocyst through its development beginning with the freshly excreted, unsporulated oocyst at “Day 0” to a fully sporulated and mature oocyst at “Day 10” and including a mid-sporulation timepoint at “Day 4”. II. Compare the transcriptomes of in vitro vs. in vivo derived bradyzoites. III. Compare expression data from three life stages (oocyst, bradyzoite and tachyzoite) from the same parasite isolate, M4, which has been been characterized as a Type II strain. Each array represents seperately isolated and processed RNA samples. (Two samples per time point/developmental stage) RNA samples were obtained from: 1. Oocysts harvested from kitten feces and purified for RNA extraction at Day 0, (not sporulated), Day 4 post-induction of sporulation (mid-sporulation) and Day 10 post-induction of sporulation (fully sporulated). Oocysts were collected and combined from two kittens that were infected with the same starting material (mouse brains containing bradyzoite cysts of the same parasite strain). Duplicate samples were obtained from feces collected and purified on separate days. 2. Bradyzoite cysts harvested from the brains of mice that were infected with oocysts from the same strain (obtained from the oocysts harvested from kittens as described for the oocyst RNA). Mice were treated with 0.44 µg/ml sulfadiazine in their water days 11-21 pi. Mice were sacrificed on day 21 for cyst purification. 3. In vitro 4 and 8 dpi bradyzoite and 2 dpi tachyzoite samples are from separately infected cultures of human foreskin fibroblasts (HFFs) (replicates were infected on the same day). The parasites used for the initial infections were derived from the same culture. Samples were harvested independently and kept separate for all the subsequent processing and labeling steps.

ORGANISM(S): Toxoplasma gondii

SUBMITTER: Kerry Buchholz

PROVIDER: E-GEOD-32427 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:Background: Considerable work has been carried out to understand the biology of the intermediate stages, the tachyzoite and bradyzoite, of Toxoplasma gondii in large part due to the accessible culturing methods for these stages. However, culturing methods for stages beyond the bradyzoite, including the merozoite and sexual stages, have not been developed hindering the ability to study a large portion of the parasite’s life cycle. We begin to unravel the molecular aspects of the merozoite stage focusing on gene expression. Results: To initiate this, we harvested merozoite parasites and hybridized mRNA to the Affymetrix Toxoplasma GeneChip. We analyzed the merozoite data in context of the life cycle by combining it with a previously published study that generated array data for the oocyst, tachyzoite, and bradyzoite stages (Fritz HM et al. PLoS One, 2012). Principal component analysis highlights the unique profile of the merozoite samples, placing them approximately half-way on a continuum between the tachyzoite/bradyzoite and oocyst samples. Prior studies have shown that antibodies to surface antigen p30 (SAG1) and many dense granule proteins do not label merozoites, and our microarray data confirms that these genes are not expressed at this stage. Also, the expression for many rhoptry and microneme proteins is drastically reduced while the expression for many surface antigens is increased at the merozoite stage. Gene Ontology and KEGG analysis reveals that genes involved in transcription/translation and many metabolic pathways are upregulated at the merozoite stage, highlighting unique growth requirements of this stage. We also show that an upstream promoter region of a merozoite specific gene is sufficient to control stage specific expression at the merozoite stage. Conclusion: The merozoite represents the first developmental stage within the gut of the definitive host. Determining the correct conditions that coax the parasite into the merozoite stage in vitro may allow the parasite to complete sexual development. The data presented here describe the global gene expression profile of merozoite stage and the creation of transgenic parasite strains that will be useful in unlocking how the parasite senses and responds to the felid gut environment to initiate coccidian development. The ToxoGeneChip microarray was used to measure both tachyzoite and merozoite mRNA expression in the type II TgNmBr1 strain.

Dataset Information

Transcriptome analysis of oocyst, tachyzoite, and bradyzoite development in the type II Toxoplasma gondii strain M4.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure