Circular RNAs Expressing in different developmental stages of the chicken bursa of Fabricius

Abstract The bursa of Fabricius plays an essential role in B lymphocyte development, which is controlled not only by proteins but by non-coding RNAs. Circular RNAs (circRNAs) are expressed in diverse tissues in eukaryotes. In order to acquire a deeper perception of the molecular mechanism of bursal development, RNA sequencing was used to identify the circRNAs during varied evolving stages of the chicken bursa of Fabricius. We identified 13689 circRNAs. All these circRNAs, were originated from 4565 chicken genes. Among them, only one circRNA was yielded from those 4131 parental genes, and two or more circular isoforms were generated from the remaining genes. There were 27 circRNAs found to be differentially expressed between the embryonic day (ED) 20 and Day_2 (D2) developmental stages. The 5 isoforms of IGLL1 circRNAs were tested to validate the RNA sequencing data, and their targeted genes were also analysed with qRT-PCR. These data indicate that cirRNAs are abundant and essential during bursal development and may play essential roles in the development of bursa of Fabricius.