Identification and expression characteristics of circular transcript of chicken insulin degrading enzyme gene

Previous high-throughput sequencing results showed that there might be a circular transcript of chicken insulin degrading enzyme (IDE) gene. In order to determine the real existence of IDE gene circular transcript (circIDE) and explore its expression pattern, RT-PCR was performed after total RNA was treated with RNase R, and Junction location was used. Specific dispersed primers and full-length primers were designed for PCR, and the circular structure and sequence information of circIDE were identified by Sanger sequencing. Real-time fluorescence quantitative PCR (qPCR) was used to analyze the temporal expression of circIDE and IDE in chickens at 1 - 12 weeks of age and tissue expression at 1 - 12 weeks of age. The positive expression of circIDE and IDE RNA was compared. The expression of liver and duodenum in Normal and Dwarf barred plymouth chicken were different. Sanger sequencing showed that, the full length of circIDE in chickens was 1326 nt, which was formed by circularization of exon 2 - 11 of IDE gene. circIDE was highly expressed in liver, heart, duodenum and other tissues, and lowly expressed in pectoral and leg muscle tissues. In liver tissues, circIDE was observed to be lowly expressed in 1 - 6 weeks, but highly expressed in 8 - 12 weeks, whiles the expression of IDE gene was high in liver. The low expression pattern observed in the liver tissue was similar to that of circIDE, which showed low expression during 1 - 6 weeks and high expression after 8 weeks. The expression of circIDE and IDE in normal chicken tissues was significantly higher than that of the dwarf chickens. This study confirmed that there is a circIDE in chicken IDE gene. The expression of circIDE in various tissues is regular, and its temporal expression pattern was similar to its linear transcript. The expression of circIDE in liver was significantly higher than that of the muscle. In addition, although circIDE was expressed in the dwarf barred plymouth chicken and the normal barred plymouth chicken, the GHR-IGFs found in the dwarf barred plymouth chicken had some defects.