High-throughput sequencing revealed the expression profile and potential key molecular of circular RNAs involved in the process of hypoxic adaptation in Tibetan chicken

Background. Tibetan chicken (Gallus gallus) provides high quality protein and iron for humans. Study of the genetic mechanisms of circular RNAs (circRNAs) in hypoxic adaptation has not been reported.Method. In the current study, four embryonic heart tissues of Tibetan chicken and Daheng broiler were collected and identified differentially expressed circRNAs (DEcircRNAs) expression using high throughput sequencing, respectively. Subsequently, bioinformatics analysis was used to indicate the functions and pathways of the DEcircRNAs.Results. A total of 2449 circRNAs were obtained in eight samples; as a result, 29 DEcircRNAs were identified between 4 Tibetan chickens and 4 Daheng broilers, including 15 up-regulated and 14 down-regulated in Tibetan chickens. The DEcircRNAs took part in gene ontology (GO) terms of insulin metabolic process, cadherin binding, cytoplasmic mRNA processing body, adherens junction. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways showed that DEcircRNAs were mainly enriched in tight junction, N-Glycan biosynthesis, protein digestion and absorption, fat digestion and absorption pathways. We also constructed a ceRNA network to visualize the regulatory relationship of tight junction pathways by Cytoscape.Conclusion. The circRNA expression profile was obtained for complement the current Tibetan chicken circRNA database and provides new ideas for future studies on biological adaptation to hypoxic stress in the Tibetan chicken.