Dynamic expression and functional analysis of circular RNA in the gonads of Chinese soft-shelled turtles (Pelodiscus sinensis).

Circular RNA (circRNA) is a noncoding RNA that can regulate a variety of biological processes. CircRNAs can regulate gene expression posttranscriptionally by acting as microRNA sponges. Many turtle species are remarkable organisms due to their reproductive processes. However, information on circRNA in the gonads of turtles is limited. In this study, 6, 121 circRNAs were identified in the testes and ovaries of Chinese soft-shelled turtles (Pelodiscus sinensis) using the Illumina platform, and 710 circRNAs were significantly differentially expressed (DE). The DE circRNAs included 541 upregulated and 169 downregulated circRNAs in the testes. GO and KEGG pathway analysis indicated that the DE circRNAs were enriched in several signaling pathways, including GnRH, Wnt, FoxO, Progesterone mediated oocyte maturation, and mTOR signaling pathways. Five DE circRNAs were randomly selected, and their relative expression levels in ovaries and testes were detected by quantitative real-time PCR. All of these circRNAs were differentially expressed. In addition, 9, 883 interactions between circRNAs and miRNAs were predicted in the turtles. Target genes of the miRNAs include a range of genes regulating gonadal development. Seven ceRNA networks (DE circRNAs-DE miRNAs-DE mRNAs), including 7 DE circRNAs, 11 DE miRNAs and 20 DE mRNAs, were constructed. The networks included Cdc6, the miR-1 family, the miR-203 family, and the miR-302 family. The expression profile of gonadal circRNAs might help to elucidate the roles of nonprotein coding RNAs in turtle gonadal development.

Ma X ，Wang G ，Wu L ，Liu H ，Jiang H ，Wang L ，Liu Q ，Wu Q ，Tian X ，Li X ... -  《-》

Genome-wide identification and comparison of differentially expressed profiles of miRNAs and lncRNAs with associated ceRNA networks in the gonads of Chinese soft-shelled turtle, Pelodiscus sinensis.

Ma X ，Cen S ，Wang L ，Zhang C ，Wu L ，Tian X ，Wu Q ，Li X ，Wang X ... -  《BMC GENOMICS》

Comparative transcriptome analysis reveals the sexual dimorphic expression profiles of mRNAs and non-coding RNAs in the Asian yellow pond turtle (Meauremys mutica).

Noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) have been extensively studied in biological processes such as disease development, cell proliferation but remained unclear in sex differentiation in organisms. In this study, the transcriptome profiles were comparatively analyzed between male and female gonads in Mauremys mutica. A total of 8237 differentially expressed genes (DEGs), 9573 DE lncRNAs, 84 DE circRNAs and 665 DE miRNAs were identified between male and female gonads. Through gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) of the DE RNAs, it was revealed that the DE mRNAs were majorly involved in GO terms, such as 'reproduction', 'reproductive process' and the pathways of 'focal adhesion' and 'oocyte meiosis'. In addition, a co-expression network showed that the expression of gametogenesis and sex differentiation related genes, including dmrt3a, tdrd7, sox14, etc were closely associated with the levels of their corresponding ncRNAs. Intriguingly, the dmrt1 circRNA and its target mRNA were detected upregulated both in adult testis and male producing temperature (MPT) embryos. Our findings demonstrated the sexually dimorphic expression profiles of mRNAs and ncRNAs in turtle gonads, which will provide the index to find out the molecular mechanisms behind the sex differentiation in turtles, even in other environmental sex determination (ESD) species.

Liu X ，Zhu Y ，Wang Y ，Li W ，Hong X ，Zhu X ，Xu H ... -  《-》

MicroRNAs May Play an Important Role in Sexual Reversal Process of Chinese Soft-Shelled Turtle, Pelodiscus sinensis.

Zhou T ，Sha H ，Chen M ，Chen G ，Zou G ，Liang H ... -  《Genes》

Identification of atrial fibrillation-related circular RNAs and constructing the integrative regulatory network of circular RNAs, microRNAs and mRNAs by bioinformatics analysis.

Zhai Z ，Qin T ，Liu F ，Han L ，Zhou H ，Li Q ，Xia Z ，Li J ... -  《-》