University of Kentucky College of Agriculture, Food & Environment


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Sarcocystis neurona Genome Sequencing Project

Sriveny Dangoudoubiyam, postdoctoral scholar
Daniel K. Howe, Ph.D.
Phone: (859) 218-1113

Sarcocystis neurona is the primary etiological agent of equine protozoal myeloencephalitis (EPM), and an emerging pathogen of marine mammals.  S. neurona belongs to the phylum Apicomplexa that includes several important pathogens of human and veterinary importance viz., Plasmodium spp., Toxoplasma gondii and Eimeria spp. Similar to other pathogenic apicomplexans, the lifecycle of S. neurona is also complex with multiple lifecycle stages viz., sporozoites, merozoites and bradyzoites. The term “zoites” is used to represent these lifecycle stages and are characterized by the presence of the apical complex. Members of this phylum also harbor a chloroplast remnant called the apicoplast, an organelle derived by secondary endosymbiosis. The genome of S.neurona was sequenced using a combination of 454 pyrosequencing and Sanger paired-end sequencing of fosmid clones. The genome sequence will be useful in many ways:

  • Mining potential diagnostic and vaccine candidates and chemotherapeutic agents

  • Provide insight into the complex biology of S. neurona

  • Reference for comparative genomics to reveal molecular diversity among different strains of S. neurona and other Sarcocystis species

  • Model to study phylogenetic relations between members of the Phylum Apicomplexa.

Useful Links:

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Graphic showing genome sequencing

454/sanger sequencing and Newbler assembly approach for S. neurona genome sequencing. Shotgun, paired end reads (3kb and 8kb), fosmid clones with 40kb inserts of S. neurona genome were generated for sequencing. Sequenced reads were assembled using Newbler genome assembler.

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Graphic showing genome sequence

Completed S. neurona genome sequence and assembly status.  S. neurona genome has been sequenced to ~30x coverage and has an estimated genome size of 124 Mb. A total of 3189 contigs were generated by the assembler and 2492 of them have come together as 172 scaffolds. The largest scaffold (chromosome) assembled is ~ 11.5 Mb.

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Graphic showing schematic of genome annotation strategy

Schematic of S. neurona genome annotation strategy. Sanger ESTs and 454 transcriptome were generated and are being used in the annotation of the S. neurona genome.



Maxwell H.Gluck Equine Research Center
Department of Veterinary Science, University of Kentucky
Lexington, Kentucky 40546-0099

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