Association analysis of polymorphism in the NR6A1 gene with the lumbar vertebrae number traits in sheep.

INTRODUCTION: The vertebral number is an economically significant trait, which is associated with body length and carcass traits. Nuclear Receptor Subfamily 6, Group A, Member 1 (NR6A1) is a member of the nuclear receptor superfamily and it plays an important role in the early development of embryos. OBJECTIVES: The NR6A1 gene was considered as an important candidate for influence vertebrae number, while the potential associations between this gene and the number of lumbar vertebrae traits of sheep have not been explored. METHODS: In this study, we detected the genetic variants of NR6A1 gene and analyzed the associations of the polymorphisms with lumbar number traits in 130 Kazakh sheep. We use single-strand conformation polymorphism (SSCP) technique to detect single nucleotide polymorphism (SNP) of NR6A1 gene, and the association of the genotype and lumbar number variation was analyzed by independent Chi-square test. RESULTS: We detect SNP of NR6A1 gene by PCR-SSCP technique, and polymorphisms were only found in the coding region of exon-6 and exon-8 of NR6A1 gene. In order to investigate the connection between the SNP locus and lumbar number traits in sheep, we conducted a Chi-square test for independence for exon-6 and exon-8 of NR6A1 gene, respectively. Association analysis revealed significant associations between the SNP (rs414302710: A >C) in the exon-8 of NR6A1 gene with the number of lumbar vertebrae (P < 0.01). CONCLUSION: Our study indicated that this SNP (rs414302710: A>C) locus of exon-8 of NR6A1 gene in sheep possible influence the number of lumbar vertebrae, which has the potential to be applied in selective breeding of sheep.

Comprehensive Expression Profiling Analysis of Pituitary Indicates that circRNA Participates in the Regulation of Sheep Estrus.

The pituitary gland is the most important endocrine organ that mainly regulates animal estrus by controlling the hormones synthesis. There is a significant difference between the estrus state and anestrus state of sheep pituitary system. Here, we studied the circular RNA (circRNA) expression profiles of the anterior pituitary of estrus and anestrus sheep using RNA-seq technology. Through this study, we identified a total of 12,468 circRNAs and 9,231 differentially expressed circRNAs in the estrus and anestrus pituitary system of sheep. We analyzed some differentially expressed circRNAs by reverse transcription quantitative-PCR (RT-qPCR), and some circRNAs were demonstrated using RNase-R+ resistance experiments. CircRNAs involving the regulation of estrus-related terms and pathways are enriched by using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. In addition, we also predicted partial microRNA-circRNA interaction network for circRNAs that regulate sheep estrus. Overall, this study explored a potential substantial role played by circRNAs involved in pituitary regulation on sheep estrus and proposed new questions for further study.

Expression profiles of circular RNAs in sheep skeletal muscle.

OBJECTIVE: Circular RNAs (circRNAs) are a newfound class of non-coding RNA in animals and plants. Recent studies have revealed that circRNAs play important roles in cell proliferation, differentiation, autophagy and apoptosis during development. However, there are few reports about muscle development-related circRNAs in livestock. METHODS: RNA sequencing analysis was employed to identify and annotate circRNAs from longissimus dorsi of sheep. Reverse transcription followed by real-time quantitative (q) polymerase chain reaction (PCR) analysis verified the presence of these circRNAs. Targetscan7.0 and miRanda were used to analyse the interaction of circRNA-microRNA (miRNA). To investigate the function of circRNAs, an experiment was conducted to perform enrichment analysis hosting genes of circRNAs using gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathways. RESULTS: About 75.5 million sequences were obtained from RNA libraries of sheep skeletal muscle. These sequences were mapped to 729 genes in the sheep reference genome. We identified 886 circRNAs, including numerous circular intronic RNAs and exonic circRNAs. Reverse transcription PCR (RT-PCR) and DNA sequencing analysis confirmed the presence of several circRNAs. Real-Time RT-PCR analysis exhibited resistance of sheep circRNAs to RNase R digestion. We found that many circRNAs interacted with muscle-specific miRNAs involved in growth and development of muscle, especially circ776. The GO and KEGG enrichment analysis showed that hosting genes of circRNAs was involved in muscle cell development and signaling pathway. CONCLUSION: The study provides comprehensive expression profiles of circRNAs in sheep skeletal muscle. Our study offers a large number of circRNAs to facilitate a better understanding of their roles in muscle growth. Meanwhile, we suggested that circ776 could be analyzed in future study.