CircRNAs in the tree shrew (Tupaia belangeri) brain during postnatal development and aging

Abstract

Circular RNAs (circRNAs) are a novel type of non-coding RNA expressed across different species and tissues. At present, little is known about the expression and function of circRNAs in the tree shrew brain. In this study, we used RNA-seq to identify 35,007 circRNAs in hippocampus and cerebellum samples from infant (aged 47–52 days), young (aged 15–18 months), and old (aged 78–86 months) tree shrews. We observed no significant changes in the total circRNA expression profiles in different brain regions over time. However, circRNA tended to be downregulated in the cerebellum over time. Real-time RT-PCR analysis verified the presence of circRNAs. KEGG analysis indicated the occurrence of ubiquitin-mediated proteolysis, the MAPK signaling pathway, phosphatidylinositol signaling system, long-term depression, the rap1 signaling pathway, and long-term potentiation in both brain regions. We also observed that 29,087 (83.1%) tree shrew circRNAs shared homology with human circRNAs. The competing endogenous RNA networks suggested novel_circRNA_007362 potential functions as a 24-miRNAs sponge to regulate UBE4B expression. Thus, we obtained comprehensive circRNA expression profiles in the tree shrew brain during postnatal development and aging, which might help to elucidate the functions of circRNAs during brain aging and in age-related diseases.

Identification and characterization of human ovary-derived circular RNAs and their potential roles in ovarian aging

“…From a wide range of organisms, including C. elegans [ 13 ], Drosophila [ 12 ], mice [ 10 ], rats [ 28 ], monkeys [ 11 ], tree shrews [ 29 ], and pigs [ 30 ], a large number of circRNAs significantly changed during aging were identified. For example, the accumulation of circRNAs in the brain was discovered across different species compared to their linear isoforms [ 10 , 13 , 23 , 29 ]. This may account for the abundant enrichment of post-mitotic cells in neural tissues and the high stability of circRNAs in cells [ 13 ].…”

Comparative genomic analysis of Proteus spp. isolated from tree shrews indicated unexpectedly high genetic diversity

“…The tree shrew (Tupaia belangeri) is a new laboratory animal belonging to the family Tupaiidae, order Scandentia, widely distributed in South Asia, Southeast Asia and Southwest China [8]. This small mammal is similar in appearance to the squirrel and feeds on insects, fruits and small vertebrates.…”

Current status and potential role of circular RNAs in neurological disorders

“…Until recently, circRNAs were believed to be transcription byproducts because their functions were unclear. However, deep sequencing has led to identification of many new circRNAs in various species such as Caenorhabditiselegans , zebrafish, Arabidopsis thaliana , Plasmodium falciparum , pigs, and tree shrews (Memczak et al ; Wang et al ; Veno et al ; Lu et al ) (Fig. ).…”