Project description:Background: Cryptosporidium baileyi is the most common Cryptosporidium species in birds. However, effective prevention measures and treatment for C. baileyi infection were less understood. Long non-coding RNA (lncRNA) and circular RNA (circRNA) were discovered to play an important role in regulating occurrence and progression of many diseases and identified as effective biomarkers for diagnosis and prognosis of several diseases. In the present study, the expression profiles of mRNA, lncRNA and circRNA associated with C. baileyi infection were investigated for the first time. Results: The tracheal tissues of experimental (C. baileyi infection) and control chickens were collected for deep RNA sequencing, and 545,479,934 clean reads were obtained. Of them, 1376 novel lncRNAs were identified, including 1161 long intergenic non-coding RNAs (lincRNAs) and 215 anti-sense lncRNAs. 124 lncRNAs were found to be significantly differentially expressed between experimental and control groups. Additionally, 14,698 mRNAs and 9085 circRNAs were identified, and significantly different expressions were observed for 1317 mRNAs and 104 circRNAs between two groups. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of their targets and background genes suggested that these dysregulated genes would be involved in the interaction between host and C. baileyi. Conclusions: The present study firstly provides the expression profiles of mRNAs, lncRNAs and circRNAs during C. baileyi infection, and describes a novel perspective on the potential roles of lncRNAs and circRNAs underlying the pathogenesis mechanism of Cryptosporidium infection.