Post-2 Hox expression in developing larval stages of Hymenolepis microstoma from the haemocoel of a flour beetle (Tribolium confusum) ~200X | photo by PD Olson
Confocal image of the Hymenolepis microstoma scolex and neck region (muscle in green; cell nuclei in blue) | image A Gruhl & PD Olson
Developmental genes in the life cycle of a parasitic flatworm
This a 3-year BBSRC-sponsored research programme aimed at understanding the complement, structure and roles of Hox genes in the complex developmental life cycle of a parasitic flatworm. Using a beetle and mouse-hosted model tapeworm, Hymenolepis microstoma, we are currently characterizing the sequences and expression patterns of its Hox and ParaHox genes. This preliminary work has been conducted with assistance from Jackie Mackenzie-Dodds and Pat Dyal and underwritten by the Department of Zoology.
BBSRC funding begins In March 2009 when we will be joined by Dr Natasha Pouchkina-Stantcheva. Natasha accepted the PDRA post in December and brings with her a wealth of experience in expression analysis and functional genomics and we look forward to her taking the project forward in the coming years.
Together with Project Partner Gabi Hrckova, the first thing we will do is establish in vitro cultivation of the model and begin testing methods of gene suppression via RNAi which has yet to be demonstrated in a cestode. The project also benefits from Project Partner Peter Holland who, together with the Oxford Evolutionary Biology group, provides an expert sounding board for our work.
FUTURE DIRECTIONS
Posterior Hox genes are downstream targets of β-catenin, which is in turn regulated through the Wnt pathway. In 2008, β-catenin was shown to regulate head development in regenerating planarians, thus solving a century old question. Conservation of the Wnt pathway in the animal kingdom has shown that it is responsible for posterior growth in deuterstomes and protostomes, and also likely in lophotrochozoans, such as flatworms. We are interested in examining the Wnt pathway with respect to the process of segmentation in tapeworms, and of the roles of β-catenin and posterior Hox genes in particular. It is expected that the transcriptomic work we are undertaking will reveal partial sequences of many of these genes, allowing us to more quickly characterize their spatial expression patterns and function.
RELATED PUBLICATIONS:
Riddiford N and PD Olson. 2011. Wnt gene loss in flatworms. Development Genes and Evolution 221:187-197 PDF | PubMed
Pouchkina-Stantcheva NN, LJ Cunningham and PD Olson. 2011. Spatial and temporal consistency of putative reference genes for real-time PCR in a model tapeworm. Molecular and Biochemical Parasitology 180:120-122 PDF | PubMed
Cunningham LJ and PD Olson. 2010. Description of Hymenolepis microstoma (Nottingham strain): a classical tapeworm model for research in the genomic era. Parasites & Vectors 3:123 PDF | PubMed
Olson PD. 2008. Invited Review: Hox genes and the parasitic flatworms: new opportunities, challenges and lessons from the free-living. Parasitology International 57:8-17 PDF | PubMed
This a 3-year BBSRC-sponsored research programme aimed at understanding the complement, structure and roles of Hox genes in the complex developmental life cycle of a parasitic flatworm. Using a beetle and mouse-hosted model tapeworm, Hymenolepis microstoma, we are currently characterizing the sequences and expression patterns of its Hox and ParaHox genes. This preliminary work has been conducted with assistance from Jackie Mackenzie-Dodds and Pat Dyal and underwritten by the Department of Zoology.
BBSRC funding begins In March 2009 when we will be joined by Dr Natasha Pouchkina-Stantcheva. Natasha accepted the PDRA post in December and brings with her a wealth of experience in expression analysis and functional genomics and we look forward to her taking the project forward in the coming years.
Together with Project Partner Gabi Hrckova, the first thing we will do is establish in vitro cultivation of the model and begin testing methods of gene suppression via RNAi which has yet to be demonstrated in a cestode. The project also benefits from Project Partner Peter Holland who, together with the Oxford Evolutionary Biology group, provides an expert sounding board for our work.
FUTURE DIRECTIONS
Posterior Hox genes are downstream targets of β-catenin, which is in turn regulated through the Wnt pathway. In 2008, β-catenin was shown to regulate head development in regenerating planarians, thus solving a century old question. Conservation of the Wnt pathway in the animal kingdom has shown that it is responsible for posterior growth in deuterstomes and protostomes, and also likely in lophotrochozoans, such as flatworms. We are interested in examining the Wnt pathway with respect to the process of segmentation in tapeworms, and of the roles of β-catenin and posterior Hox genes in particular. It is expected that the transcriptomic work we are undertaking will reveal partial sequences of many of these genes, allowing us to more quickly characterize their spatial expression patterns and function.
RELATED PUBLICATIONS:
Riddiford N and PD Olson. 2011. Wnt gene loss in flatworms. Development Genes and Evolution 221:187-197 PDF | PubMed
Pouchkina-Stantcheva NN, LJ Cunningham and PD Olson. 2011. Spatial and temporal consistency of putative reference genes for real-time PCR in a model tapeworm. Molecular and Biochemical Parasitology 180:120-122 PDF | PubMed
Cunningham LJ and PD Olson. 2010. Description of Hymenolepis microstoma (Nottingham strain): a classical tapeworm model for research in the genomic era. Parasites & Vectors 3:123 PDF | PubMed
Olson PD. 2008. Invited Review: Hox genes and the parasitic flatworms: new opportunities, challenges and lessons from the free-living. Parasitology International 57:8-17 PDF | PubMed
Buddenbrockia plumatellae: emerging from a bryozoan (above); scanning electron micrograph (below)
Confocal image showing muscle bundles (green) and cell nuclei (red) | image A Gruhl
Developmental genes in a vermiform cnidarian parasite, Buddenbrockia
This is work led by my colleague in the Zoology Department Beth Okamura who has studied these animals extensively. Together with post-doc Alex Gruhl, we aim to explore the musculature, nervous system and expression of key developmental genes to look for evidence of triploblasty in a vermiform myxozoan parasite.
SEE POSTER:
A Gruhl and B Okamura. Muscular archetecture of Buddenbrockia plumatellae and its significance for the phylogenetic position of Myxozoa DOWNLOAD PDF (1.7 MB)
RELATED PUBLICATIONS:
Jiménez-Guri E, H Philippe, B Okamura and PWH Holland. Buddenbrockia is a cnidarian worm. Science 317:116-118.
Okamura B, A Curry, TS Wood, and EU Canning. 2002. Ultrastructure of Buddenbrockia sp. identifies it as a myxozoan and verifies the bilaterian origin of the Myxozoa. Parasitology 124:215-223
This is work led by my colleague in the Zoology Department Beth Okamura who has studied these animals extensively. Together with post-doc Alex Gruhl, we aim to explore the musculature, nervous system and expression of key developmental genes to look for evidence of triploblasty in a vermiform myxozoan parasite.
SEE POSTER:
A Gruhl and B Okamura. Muscular archetecture of Buddenbrockia plumatellae and its significance for the phylogenetic position of Myxozoa DOWNLOAD PDF (1.7 MB)
RELATED PUBLICATIONS:
Jiménez-Guri E, H Philippe, B Okamura and PWH Holland. Buddenbrockia is a cnidarian worm. Science 317:116-118.
Okamura B, A Curry, TS Wood, and EU Canning. 2002. Ultrastructure of Buddenbrockia sp. identifies it as a myxozoan and verifies the bilaterian origin of the Myxozoa. Parasitology 124:215-223