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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Parasitic Diseases Laboratory » Research » Publications at this Location » Publication #388239

Research Project: Foodborne Parasites and their Impact on Food Safety

Location: Animal Parasitic Diseases Laboratory

Title: TSS-seq of Toxoplasma gondii sporozoites revealed a novel motif in stage-specific promoters

item KIDAKA, TAISHI - Hokkaido University
item SUGI, TATSUKI - Hokkaido University
item KYOKO, HAYASHIDA - Hokkaido University
item SUZUKI, YUTAKA - University Of Tokyo
item XUAN, XUENAN - Obihiro University
item Dubey, Jitender
item YAMAGISHI, JUNYA - Hokkaido University

Submitted to: Infection, Genetics and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/11/2022
Publication Date: 1/20/2022
Citation: Kidaka, T., Sugi, T., Kyoko, H., Suzuki, Y., Xuan, X., Dubey, J.P., Yamagishi, J. 2022. TSS-seq of Toxoplasma gondii sporozoites revealed a novel motif in stage-specific promoters. Infection, Genetics and Evolution.

Interpretive Summary: Interpretive Summary: Food safety due to microbial contamination of foods remains a public health concern worldwide. Among the parasitic contaminants, fecal contamination of foods due to protozoans such as Cyclospora, Cryptosporidium, Giardia, and Toxoplasma are of prime concern. These parasites undergo marked developmental transitions from one stage to another, and these stages differ in their ability to cause infection. However, we do not fully understand how such parasites turn on and off the suites of genes that define each stage. A decade before the redirection of the its food safety program, the USDA provided a Japanese research team with materials needed to establish transcriptional start sites orchestrating gene function in sporozoites of one of these parasites. They discovered a resemblance to start sites found in other, distantly related parasites, suggesting evolutionarily conserved signals that guide developmental transitions. This information may aid efforts to discover vaccines and treatments against a wide variety of parasites that threaten veterinary and public health.

Technical Abstract: Toxoplasma gondii is one of the most common zoonotic protozoan parasites. It has three infectious stages: rapidly multiplying tachyzoites (Tz), slowly replicating bradyzoites (Bz) and a resting/free-living stage, sporozoites (Sz). The regulatory mechanisms governing stage-specific gene expression are not fully understood. Few transcriptional start sites (TSS) are known for Sz. In this study, we obtained TSS of Sz using an oligo-capping method and RNA-seq analysis. We identified 1,043,503 TSS in the Sz transcriptome. These defined 38,973 TSS clusters, of which, 11,925 were expressed in Sz and 1,535 TSS differentially expressed in Sz. Based on these data, we defined promoter regions and novel sporozoite stage-specific motifs using MEME. TGTANNTACA was distributed around –55 to –75 regions from each TSS. Interestingly, the same motif was reported in another apicomplexan, Plasmodium berghei, as a cis-element of female-specific gametocyte genes, implying the presence of common regulatory machinery. Further comparative analysis should better define the distribution and function of these elements in other members of this important parasitic phylum.