Background: In order to explore the differential expression of circular RNA (circRNA) in the subcutaneous fat tissue of Qinghai yaks under different feeding methods during the dry grass period and its regulatory mechanism. 
 
Methods: The present study adopted Illumina sequencing technology to sequence the transcriptome of subcutaneous fat tissue of Qinghai yaks naturally grazed and fattened by housed feeding during the dry grass period and used bioinformatics software to screen out the differentially expressed. The circRNAs were screened for differential expression using bioinformatics software. circRNAs related to fat metabolism were screened by GO function and KEGG pathway enrichment analysis of their source genes and three differentially expressed circRNAs were randomly screened and the expression of the circRNAs was verified by real-time fluorescence quantitative PCR (qRT-PCR).&nbsp; 
 
Result: Transcriptome sequencing results showed that a total of 628 differentially expressed circRNAs were obtained, of which 219 were up-regulated and 409 were down-regulated. GO functional enrichment analysis showed that the circRNAs in the free-grazing group originated from genes for major molecular constructs, cellular parts, organs, bioregulation and cellular processes, etc. KEGG pathway enrichment analysis showed that the circRNAs could be participate in signaling pathways such as phagosomes, protein digestion and absorption. qRT-PCR results showed that the expression levels of the three circRNAs were consistent with the sequencing results and the sequencing results were accurate and reliable. This experiment provides a molecular basis for further understanding of fat metabolism in yaks.

Differential circRNA Screening and Identification of Subcutaneous Fat Tissue in Plateau-type Yaks under Different Feeding Methods

<div>Background:&nbsp;Circular RNAs (circRNAs), a novel class of endogenous non-coding RNAs with covalently closed loop structures, play important role in mammalian growth and development by regulating gene expression and participating in various biological processes. The aim of this study was to identify the expression profiles of circRNAs in the ovaries of Hu sheep and local Fat-tailed sheep during the luteal phase to determine the molecular mechanisms underlying the effects of circRNAs on reproduction and follicular development in sheep. 
 
Methods: To identify the differentially expressed circRNAs expressed in luteal phase conditions in Hu sheep and fat-tailed sheep, ovarian samples collected during the luteal phase were analyzed using high-throughput sequencing and subsequent transcriptomic approaches and bioinformatics analysis. 
 
Result:&nbsp;A total of 2,875 differentially expressed circRNAs were identified by high-through sequencing. Gene Ontology terminology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the host genes were mainly involved in the secretion and metabolism of the various pathway. Quantitative real-time PCR was performed to validate the results of expression profiling. These results contributed to an improved understanding of circRNA and the biological mechanisms of ovarian reproduction in sheep.</div>

Differential circRNA Screening and Identification of Subcutaneous Fat Tissue in Plateau-type Yaks under Different Feeding Methods

Identification of Circular RNAs in the Ovaries of Hu Sheep and Local Fat-tailed Sheep during the Luteal Phase