RNA-Seq of Phenotypically Distinct Eimeria maxima Strains Reveals Coordinated and Contrasting Maturation and Shared Sporogonic Biomarkers with Eimeria acervulina

Authors: Tucker, Matthew; Obrien, Celia; JOHNSON, ALEXIS - US Department Of State; Dubey, Jitender; Rosenthal, Benjamin; Jenkins, Mark

Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2023
Publication Date: 12/19/2023
Citation: Tucker, M.S., Obrien, C.N., Johnson, A.N., Dubey, J.P., Rosenthal, B.M., Jenkins, M.C. 2023. RNA-Seq of Phenotypically Distinct Eimeria maxima Strains Reveals Coordinated and Contrasting Maturation and Shared Sporogonic Biomarkers with Eimeria acervulina. Pathogens. 13(1): Article e13010066. https://doi.org/10.3390/pathogens13010002.
DOI: https://doi.org/10.3390/pathogens13010002

Interpretive Summary: Managing the harms posed by enteric parasites benefits both animal husbandry and food safety. For example, parasites in the family coccidia include Eimeria, that harm poultry health and production, and Cyclospora cayetanensis, which compromises produce safety. Here, USDA researchers in Beltsville, Maryland examined commonalities in the repertoire of genes expressed by two strains and two species of Eimeria, and identified certain features unique to each species and strain. The team focused on how these parasites develop to become infectious. They discovered broadly shared aspects of parasite development and noted a few genes whose distinct expression profiles may accelerate or delay development, and which may account for differences in virulence. These insights will help scientists dissect the basis of parasite virulence, may help vaccine producers and users asses the efficacy of vaccines, and may help food safety professionals better assess risk when they encounter evidence of parasite contamination in food or water.

Technical Abstract: Strains of Eimeria maxima, an enteric parasite of poultry, vary in virulence. Here, we performed microscopy and RNA sequencing on oocysts of strains APU-1 (which exhibits more virulence) and APU-2. Although each underwent parallel development, APU-1 initially approached maturation more slowly. Each strain sporulated by hour 36; their gene expression diverged somewhat thereafter. Candidate biomarkers of viability included 58 genes contributing at least 1000 Transcripts Per Million throughout sporulation, such as cation-transporting ATPases and zinc finger domain-containing proteins. Many genes resemble constitutively expressed genes also important to Eimeria acervulina. Throughout sporulation, the expression of only a few genes differed between strains; these included cyclophilin A, EF-1a, and surface antigens (SAGs). Mature and immature oocysts uniquely differentially express certain genes, such as an X-Pro dipeptidyl-peptidase domain-containing protein in immature oocysts and a profilin in mature oocysts. The immature oocysts of each strain expressed more phosphoserine aminotransferase and the mature oocysts expressed more SAGs and microneme proteins. These data illuminate processes influencing sporulation in Eimeria and related genera, such as Cyclospora, and identify biological processes which may differentiate them. Drivers of development and senescence may provide tools to assess the viability of oocysts, which would greatly benefit the poultry industry and food safety applications.