(A) Helicosporidium cyst dehiscence observed under light microscopy, showing groups of three ovoid cells (O), diagnostic filamentous cells (F) and empty pellicles (E). (B) Scanning electron micrograph detailing the filamentous cell and its barbs (pointing away from the core of ovoid cells). Figure from A. Tartar, Insects, 2013 under Creative Commons License CC BY-SA 4.0.

The Helicosporidium sp. ATCC 50920 genome sequence and gene models were not determined by the Joint Genome Institute (JGI), but were downloaded from NCBI on Oct 31, 2019. In order to ensure this genome is comparable to those sequenced by the JGI, we applied filters to remove if present: 1) transposable elements, 2) pseudogenes, 3) alternative transcripts and overlapping models, 4) alleles on secondary scaffolds and 5) unsupported short models. This resulted in the removal of 431 models and the generation of the FilteredModels2 (GeneCatalog) gene track. All published models are available in the ExternalModels track. Please note that this copy of the genome is not maintained by NCBI and is therefore not automatically updated. In order to allow comparative analyses with other algal genomes sequenced by the JGI, a copy of this genome is incorporated into PhycoCosm. The JGI Annotation Pipeline was used to add functional annotation to this genome.

The following text is from NCBI:

Helicosporidia are non-photosynthetic protists that are obligate parasites of invertebrates. These pathogens feature an unusual cyst stage that dehisces inside the infected organism and releases a filamentous cell displaying surface projections, which will penetrate the host gut wall and eventually reproduce in the hemolymph. These parasites belong to the green algal lineage Trebouxiophyceae, which encompasses free-living, symbiotic, and parasitic species.