Project description:Giardia intestinalis is a protist causing diarrhea in humans. The first G. intestinalis genome, from the WB isolate, was published more than ten years ago, and has been widely used as the reference genome for Giardia research. However, the genome is fragmented, thus hindering research at the chromosomal level. We re-sequenced the Giardia genome with Pacbio long-read sequencing technology and obtained a new reference genome, which was assembled into near-complete chromosomes with only four internal gaps at long repeats. This new genome is not only more complete but also better annotated at both structural and functional levels, providing more details about gene families, gene organizations and chromosomal structure. This near-complete reference genome will be a valuable resource for the Giardia community and protist research. It also showcases how a fragmented genome can be improved with long-read sequencing technology completed with optical maps.
Project description:The Giardia lamblia genome consists of 12 Mb divided among 5 chromosomes ranging in size from approximately 1 to 4 Mb. The assembled contigs of the genotype A1 isolate, WB, were previously mapped along the 5 chromosomes on the basis of hybridization of plasmid clones representing the contigs to chromosomes separated by PFGE. In the current report, we have generated an MluI optical map of the WB genome to improve the accuracy of the physical map. This has allowed us to correct several assembly errors and to better define the extent of the subtelomeric regions that are not included in the genome assembly.
Project description:Giardia duodenalis is a protozoan parasite responsible for gastroenteritis in vertebrates, including humans. The prevalence of G. duodenalis is partly owed to its direct and simple life cycle, as well as the formation of the environmentally resistant and infective cysts. Several proteomic and transcriptomic studies have previously analysed global changes during the encystation process using the well-characterised laboratory isolate and genome strain, WBC6. To expand current comparative analyses, this study presents the first quantitative global study of encystation using pathogenically relevant and alternative assemblage A strains: the human-derived BRIS/82/HEPU/106 and avian-derived BRIS/95/HEPU/2041. We have utilised tandem MS/MS with a label-free quantitative approach to compare cysts and trophozoite life stages between strains for variation, as well as confirm universal encystation markers of Assemblage A.
Project description:I this study we analyzed three lines, two of which were created by UV- directed mutagenesis and showed increased levels of metronidazole tolerance (M1 and M2) and the third being a line that reverted spontanously to sensitive after several passages (M1NR) of M1 without metronidazole in the media. On the physiological side we analyzed the ability of these lines to reists metronidazole exposure and to encyst as well as their respective doublings times. At the same time we conducted a trasncriptomics and proteomics analysis to understand which exact changes lead to M1 and M2 being resistant while M1NR shows wildtype levels of metrondiazole sensitivty. We than compared these datasets to already existing datasets of other metrondiazole resistant lines and managed to identify a few core changes which are shared between all lines. In all lines proteins that are activating the drug are downregulated while proteins that are part of the oxidative stress response are found in higher abundance. On the other side these core changes are accompanied by a line specific set of changes, showing that there is more than one way for Giardia intestinalis to become resistant to metronidazole.
Project description:Giardia duodenalis is the protozoan agent responsible for the majority of parasitic gastroenteritis in humans worldwide. Disease pathology includes malabsorption and maldigestion, cell apoptosis and small intestinal barrier dysfunction, which occurs in absence of known toxins, cell invasion and overt inflammation. To understand pathogenesis, host-parasite in vitro interaction models provide global insights into disease induction and virulence. Hence, we performed the first proteomic analysis of G. duodenalis trophozoites interacted with intestinal epithelial cells (IECs, HT-29) for 6 hours, and compared it to trophozoites exposed to cell-free fractions of host-soluble signals. This has allowed us to demonstrate that distinct and independent protein cascades are induced by host attachment compared to host soluble signals. We utilised a tandem mass tag (TMT) approach and evaluated it as quantitative proteomics for the first time in Giardia.
Project description:Vanee2010 - Genome-scale metabolic model of
Cryptosporidium hominis (iNV213)
This model is described in the article:
A genome-scale metabolic
model of Cryptosporidium hominis.
Vanee N, Roberts SB, Fong SS, Manque
P, Buck GA.
Chem. Biodivers. 2010 May; 7(5):
1026-1039
Abstract:
The apicomplexan Cryptosporidium is a protozoan parasite of
humans and other mammals. Cryptosporidium species cause acute
gastroenteritis and diarrheal disease in healthy humans and
animals, and cause life-threatening infection in
immunocompromised individuals such as people with AIDS. The
parasite has a one-host life cycle and commonly invades
intestinal epithelial cells. The current genome annotation of
C. hominis, the most serious human pathogen, predicts 3884
genes of which ca. 1581 have predicted functional annotations.
Using a combination of bioinformatics analysis, biochemical
evidence, and high-throughput data, we have constructed a
genome-scale metabolic model of C. hominis. The model is
comprised of 213 gene-associated enzymes involved in 540
reactions among the major metabolic pathways and provides a
link between the genotype and the phenotype of the organism,
making it possible to study and predict behavior based upon
genome content. This model was also used to analyze the two
life stages of the parasite by integrating the stage-specific
proteomic data for oocyst and sporozoite stages. Overall, this
model provides a computational framework to systematically
study and analyze various functional behaviors of C. hominis
with respect to its life cycle and pathogenicity.
This model is hosted on
BioModels Database
and identified by:
MODEL1507180071.
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An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.