John C. Boothroyd

Expansion of host range as a driving force in the evolution of Toxoplasma (2009)

Boothroyd, John C.

The apicomplexan parasite Toxoplasma gondii   is unusual in being able to infect almost any cell from almost any warm-blooded animal it encounters. This extraordinary host-range contrasts with its...

Identification of the Moving Junction Complex of Toxoplasma gondii: A Collaboration between Distinct Secretory Organelles (2005)

David L. Alexander, Jeffrey Mital, Gary E. Ward, Peter Bradley, John C. Boothroyd

Apicomplexan parasites, including Toxoplasma gondii and Plasmodium sp., are obligate intracellular protozoa. They enter into a host cell by attaching to and then creating an invagination in the host...

Composite genome map and recombination parameters derived from three archetypal lineages of Toxoplasma gondii (2005)

Khan, Asis, Taylor, Sonya, Su, Chunlei, Mackey, Aaron J., Boyle, Jon, Cole, Robert, ...

Toxoplasma gondii is a highly successful protozoan parasite in the phylum Apicomplexa, which contains numerous animal and human pathogens. T.gondii is amenable to cellular, biochemical, molecular and...

An unusually compact ribosomal DNA repeat in the protozoan Giardia lamblia (1987)

Boothroyd, John C., Wang, Alice, Campbell, David A., Wang, Ching C.

The ribosomal RNA (rRNA) genes of the protozoan parasite Giardia lamblia have been analyzed with respect to size, composition and copy number. They are found to be remarkable in several respects....

The 5'-limit of transposition and upstream barren region of a trypanosome VSG gene: tandem 76 base-pair repeats flanking (TAA)90 (1984)

Campbell, David A., Van Bree, Mark P., Boothroyd, John C.

We have cloned and sequenced a portion of the region upstream of an expressed VSG gene of Trypanosoma brucei. This “expression-linked copy” arose through the duplication and transposition of a...

Variant surface glycoproteins of Trypanosoma brucei are synthesised with cleavable hydrophobic sequences at the carboxy and amino termini (1981)

Boothroyd, John C., Paynter, Cora A., Cross, George A.M., Bernards, Andre, Borst, Piet

cDNAs coding for the amino and carboxy termini of two trypanosome variant surface glycoproteins (VSGs) have been sequenced. The results indicate that VSGs are synthesised with hydrophobic...

Homologous 3'-terminal regions of mRNAs for surface antigens of different antigenic variants of Trypanosoma brucei (1981)

Majumder, Hemanta K., Boothroyd, John C., Weber, Hans

Sequences corresponding to the complete 3′-terminal regions of the messenger RNAs for three different Variant Surface Glycoproteins of Trypanosoma brucei were determined on complementary DNA...

New genes and promoters suggested by the DNA sequence near the end of the coliphage T7 early operon (1979)

Boothroyd, John C., Hayward, Richard S.

We have employed the dideoxynucleotide chain-terminating method to deter-mine the nucleotide sequence of T7 DNA between the physical map positions 18.9% and 19.8%. The most striking features of this...

Rapid Identification of Virulent Type I Strains of the Protozoan Pathogen Toxoplasma gondii by PCR-Restriction Fragment Length Polymorphism Analysis at the B1 Gene

Grigg, Michael E., Boothroyd, John C.

Sequence analysis at the 35-fold-repetitive B1 locus identified three restriction sites capable of discriminating type I (mouse-virulent) from type II or III (mouse-avirulent) strains of Toxoplasma...

Toxoplasma gondii Homologue of Plasmodium Apical Membrane Antigen 1 Is Involved in Invasion of Host Cells

Hehl, Adrian B., Lekutis, Christine, Grigg, Michael E., Bradley, Peter J., Dubremetz, Jean-François, Ortega-Barria, Eduardo, ...

Proteins with constitutive or transient localization on the surface of Apicomplexa parasites are of particular interest for their potential role in the invasion of host cells. We describe the...

Lytic Cycle of Toxoplasma gondii

Black, Michael W., Boothroyd, John C.

Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa. This protozoan parasite is one of the most widespread, with a broad host range including many birds and mammals...

Ionophore-Resistant Mutants of Toxoplasma gondii Reveal Host Cell Permeabilization as an Early Event in Egress

Black, Michael W., Arrizabalaga, Gustavo, Boothroyd, John C.

Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa. Invasion and egress by this protozoan parasite are rapid events that are dependent upon parasite motility and...

Expressed Sequence Tag Analysis of the Bradyzoite Stage of Toxoplasma gondii: Identification of Developmentally Regulated Genes

Manger, Ian D., Hehl, Adrian, Parmley, Steve, Sibley, L. David, Marra, Marco, Hillier, Ladeana, ...

Toxoplasma gondii is a protozoan parasite responsible for widespread infections in humans and animals. Two major asexual forms are produced during the life cycle of this parasite: the rapidly...

The Surface of Toxoplasma Tachyzoites Is Dominated by a Family of Glycosylphosphatidylinositol-Anchored Antigens Related to SAG1

Manger, Ian D., Hehl, Adrian B., Boothroyd, John C.

Toxoplasma gondii is an Apicomplexan parasite with a complex life cycle that includes a rapidly dividing asexual stage known as the tachyzoite. The tachyzoite surface has been reported to comprise...

Isolation of Developmentally Regulated Genes from Toxoplasma gondii by a Gene Trap with the Positive and Negative Selectable Marker Hypoxanthine-Xanthine-Guanine Phosphoribosyltransferase

Knoll, Laura J., Boothroyd, John C.

Within its intermediate host, Toxoplasma gondii switches between two forms: a rapidly replicating tachyzoite and an encysted bradyzoite. Bradyzoites persist within the host throughout its life,...

Toxoplasma gondii Asexual Development: Identification of Developmentally Regulated Genes and Distinct Patterns of Gene Expression

Cleary, Michael D., Singh, Upinder, Blader, Ira J., Brewer, Jeremy L., Boothroyd, John C.

Asexual development in Toxoplasma gondii is a vital aspect of the parasite's life cycle, allowing transmission and avoidance of the host immune response. Differentiation of rapidly dividing...

Synchronous Growth and Plastid Replication in the Naturally Wall-less Alga Olisthodiscus luteus1

Cattolico, Rose Ann, Boothroyd, John C., Gibbs, Sarah P.

Olisthodiscus luteus is a unicellular biflagellate alga which contains many small discoidal chloroplasts. This naturally wall-less organism can be axenically maintained on a defined nonprecipitating...

Bioluminescence Imaging of Toxoplasma gondii Infection in Living Mice Reveals Dramatic Differences between Strains

Saeij, Jeroen P. J., Boyle, Jon P., Grigg, Michael E., Arrizabalaga, Gustavo, Boothroyd, John C.

We examined the in vivo growth, dissemination, and reactivation of strains of the protozoan parasite Toxoplasma gondii using a bioluminescence-based imaging system. Two T. gondii strains, one with a...

Composite genome map and recombination parameters derived from three archetypal lineages of Toxoplasma gondii

Khan, Asis, Taylor, Sonya, Su, Chunlei, Mackey, Aaron J., Boyle, Jon, Cole, Robert, ...

Toxoplasma gondii is a highly successful protozoan parasite in the phylum Apicomplexa, which contains numerous animal and human pathogens. T.gondii is amenable to cellular, biochemical, molecular and...

Disruption of a Locus Encoding a Nucleolar Zinc Finger Protein Decreases Tachyzoite-to-Bradyzoite Differentiation in Toxoplasma gondii

Vanchinathan, Padmini, Brewer, Jeremy L., Harb, Omar S., Boothroyd, John C., Singh, Upinder

During its life cycle in intermediate hosts, Toxoplasma gondii exists in two interconverting developmental stages: tachyzoites and bradyzoites. This interconversion is essential for the survival and...

Identification of the Moving Junction Complex of Toxoplasma gondii: A Collaboration between Distinct Secretory Organelles

Alexander, David L, Mital, Jeffrey, Ward, Gary E, Bradley, Peter, Boothroyd, John C

Apicomplexan parasites, including Toxoplasma gondii and Plasmodium sp., are obligate intracellular protozoa. They enter into a host cell by attaching to and then creating an invagination in the host...

Plasmodium falciparum AMA1 Binds a Rhoptry Neck Protein Homologous to TgRON4, a Component of the Moving Junction in Toxoplasma gondii

Alexander, David L., Arastu-Kapur, Shirin, Dubremetz, Jean-Francois, Boothroyd, John C.

Plasmodium falciparum apical membrane antigen 1 (PfAMA1) coimmunoprecipitates with the Plasmodium homologue of TgRON4, a secreted rhoptry neck protein of Toxoplasma gondii that migrates at the moving...

Rapid Identification of Virulent Type I Strains of the Protozoan Pathogen Toxoplasma gondii by PCR-Restriction Fragment Length Polymorphism Analysis at the B1 Gene

Grigg, Michael E., Boothroyd, John C.

Sequence analysis at the 35-fold-repetitive B1 locus identified three restriction sites capable of discriminating type I (mouse-virulent) from type II or III (mouse-avirulent) strains of Toxoplasma...

Toxoplasma gondii Homologue of Plasmodium Apical Membrane Antigen 1 Is Involved in Invasion of Host Cells

Hehl, Adrian B., Lekutis, Christine, Grigg, Michael E., Bradley, Peter J., Dubremetz, Jean-François, Ortega-Barria, Eduardo, ...

Proteins with constitutive or transient localization on the surface of Apicomplexa parasites are of particular interest for their potential role in the invasion of host cells. We describe the...

Lytic Cycle of Toxoplasma gondii

Black, Michael W., Boothroyd, John C.

Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa. This protozoan parasite is one of the most widespread, with a broad host range including many birds and mammals...

Ionophore-Resistant Mutants of Toxoplasma gondii Reveal Host Cell Permeabilization as an Early Event in Egress

Black, Michael W., Arrizabalaga, Gustavo, Boothroyd, John C.

Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa. Invasion and egress by this protozoan parasite are rapid events that are dependent upon parasite motility and...

Expressed Sequence Tag Analysis of the Bradyzoite Stage of Toxoplasma gondii: Identification of Developmentally Regulated Genes

Manger, Ian D., Hehl, Adrian, Parmley, Steve, Sibley, L. David, Marra, Marco, Hillier, Ladeana, ...

Toxoplasma gondii is a protozoan parasite responsible for widespread infections in humans and animals. Two major asexual forms are produced during the life cycle of this parasite: the rapidly...

The Surface of Toxoplasma Tachyzoites Is Dominated by a Family of Glycosylphosphatidylinositol-Anchored Antigens Related to SAG1

Manger, Ian D., Hehl, Adrian B., Boothroyd, John C.

Toxoplasma gondii is an Apicomplexan parasite with a complex life cycle that includes a rapidly dividing asexual stage known as the tachyzoite. The tachyzoite surface has been reported to comprise...

Isolation of Developmentally Regulated Genes from Toxoplasma gondii by a Gene Trap with the Positive and Negative Selectable Marker Hypoxanthine-Xanthine-Guanine Phosphoribosyltransferase

Knoll, Laura J., Boothroyd, John C.

Within its intermediate host, Toxoplasma gondii switches between two forms: a rapidly replicating tachyzoite and an encysted bradyzoite. Bradyzoites persist within the host throughout its life,...

Toxoplasma gondii Asexual Development: Identification of Developmentally Regulated Genes and Distinct Patterns of Gene Expression

Cleary, Michael D., Singh, Upinder, Blader, Ira J., Brewer, Jeremy L., Boothroyd, John C.

Asexual development in Toxoplasma gondii is a vital aspect of the parasite's life cycle, allowing transmission and avoidance of the host immune response. Differentiation of rapidly dividing...

Synchronous Growth and Plastid Replication in the Naturally Wall-less Alga Olisthodiscus luteus1

Cattolico, Rose Ann, Boothroyd, John C., Gibbs, Sarah P.

Olisthodiscus luteus is a unicellular biflagellate alga which contains many small discoidal chloroplasts. This naturally wall-less organism can be axenically maintained on a defined nonprecipitating...

Bioluminescence Imaging of Toxoplasma gondii Infection in Living Mice Reveals Dramatic Differences between Strains

Saeij, Jeroen P. J., Boyle, Jon P., Grigg, Michael E., Arrizabalaga, Gustavo, Boothroyd, John C.

We examined the in vivo growth, dissemination, and reactivation of strains of the protozoan parasite Toxoplasma gondii using a bioluminescence-based imaging system. Two T. gondii strains, one with a...

Composite genome map and recombination parameters derived from three archetypal lineages of Toxoplasma gondii

Khan, Asis, Taylor, Sonya, Su, Chunlei, Mackey, Aaron J., Boyle, Jon, Cole, Robert, ...

Toxoplasma gondii is a highly successful protozoan parasite in the phylum Apicomplexa, which contains numerous animal and human pathogens. T.gondii is amenable to cellular, biochemical, molecular and...

Disruption of a Locus Encoding a Nucleolar Zinc Finger Protein Decreases Tachyzoite-to-Bradyzoite Differentiation in Toxoplasma gondii

Vanchinathan, Padmini, Brewer, Jeremy L., Harb, Omar S., Boothroyd, John C., Singh, Upinder

During its life cycle in intermediate hosts, Toxoplasma gondii exists in two interconverting developmental stages: tachyzoites and bradyzoites. This interconversion is essential for the survival and...

Identification of the Moving Junction Complex of Toxoplasma gondii: A Collaboration between Distinct Secretory Organelles

Alexander, David L, Mital, Jeffrey, Ward, Gary E, Bradley, Peter, Boothroyd, John C

Apicomplexan parasites, including Toxoplasma gondii and Plasmodium sp., are obligate intracellular protozoa. They enter into a host cell by attaching to and then creating an invagination in the host...

Plasmodium falciparum AMA1 Binds a Rhoptry Neck Protein Homologous to TgRON4, a Component of the Moving Junction in Toxoplasma gondii

Alexander, David L., Arastu-Kapur, Shirin, Dubremetz, Jean-Francois, Boothroyd, John C.

Plasmodium falciparum apical membrane antigen 1 (PfAMA1) coimmunoprecipitates with the Plasmodium homologue of TgRON4, a secreted rhoptry neck protein of Toxoplasma gondii that migrates at the moving...

Just one cross appears capable of dramatically altering the population biology of a eukaryotic pathogen like Toxoplasma gondii

Boyle, Jon P., Rajasekar, Badri, Saeij, Jeroen P. J., Ajioka, James W., Berriman, Matthew, Paulsen, Ian, ...

Toxoplasma gondii, an obligate intracellular protozoan of the phylum Apicomplexa, is estimated to infect over a billion people worldwide as well as a great many other mammalian and avian hosts....

Toxoplasma gondii Targets a Protein Phosphatase 2C to the Nuclei of Infected Host Cells▿ †

Gilbert, Luke A., Ravindran, Sandeep, Turetzky, Jay M., Boothroyd, John C., Bradley, Peter J.

Intracellular pathogens have evolved a wide array of mechanisms to invade and co-opt their host cells for intracellular survival. Apicomplexan parasites such as Toxoplasma gondii employ the action of...

Bradyzoite-Specific Surface Antigen SRS9 Plays a Role in Maintaining Toxoplasma gondii Persistence in the Brain and in Host Control of Parasite Replication in the Intestine▿

Kim, Seon-Kyeong, Karasov, Ariela, Boothroyd, John C.

Toxoplasma gondii is a ubiquitous parasite that persists for the life of a healthy mammalian host. A latent, chronic infection can reactivate upon immunosuppression and cause life-threatening...

Behavioral changes induced by Toxoplasma infection of rodents are highly specific to aversion of cat odors

Vyas, Ajai, Kim, Seon-Kyeong, Giacomini, Nicholas, Boothroyd, John C., Sapolsky, Robert M.

The protozoan parasite Toxoplasma gondii blocks the innate aversion of rats for cat urine, instead producing an attraction to the pheromone; this may increase the likelihood of a cat predating a rat....

Ionophore-resistant mutant of Toxoplasma gondii reveals involvement of a sodium/hydrogen exchanger in calcium regulation

Arrizabalaga, Gustavo, Ruiz, Felix, Moreno, Silvia, Boothroyd, John C.

Calcium is a critical mediator of many intracellular processes in eukaryotic cells. In the obligate intracellular parasite Toxoplasma gondii, for example, a rise in [Ca2+] is associated with...

A Cluster of Four Surface Antigen Genes Specifically Expressed in Bradyzoites, SAG2CDXY, Plays an Important Role in Toxoplasma gondii Persistence▿

Saeij, Jeroen P. J., Arrizabalaga, Gustavo, Boothroyd, John C.

Toxoplasma gondii is one of the most successful protozoan parasites of warm-blooded animals. Stage-specific expression of its surface molecules is thought to be key to its ability to establish...

Expression Quantitative Trait Locus Mapping of Toxoplasma Genes Reveals Multiple Mechanisms for Strain-Specific Differences in Gene Expression ▿

Boyle, Jon P., Saeij, Jeroen P. J., Harada, Scott Y., Ajioka, Jim W., Boothroyd, John C.

Toxoplasma gondii is an intracellular parasite with a significant impact on human health, especially in cases where individuals are immunocompromised (e.g., due to human immunodeficiency virus/AIDS)....

The Toxoplasma gondii Dense Granule Protein GRA7 Is Phosphorylated upon Invasion and Forms an Unexpected Association with the Rhoptry Proteins ROP2 and ROP4▿

Dunn, Joe Dan, Ravindran, Sandeep, Kim, Seon-Kyeong, Boothroyd, John C.

The obligate intracellular parasite Toxoplasma gondii infects warm-blooded animals throughout the world and is an opportunistic pathogen of humans. As it invades a host cell, Toxoplasma forms a novel...

A Pseudouridine Synthase Homologue Is Critical to Cellular Differentiation in Toxoplasma gondii▿

Anderson, Matthew Z., Brewer, Jeremy, Singh, Upinder, Boothroyd, John C.

Toxoplasma gondii is a haploid protozoan parasite infecting about one in seven people in the United States. Key to the worldwide prevalence of T. gondii is its ability to establish a lifelong,...