Profile of microRNA in Giant Panda Blood: A Resource for Immune-Related and Novel microRNAs.

Mingyu Yang,Xiuyue Zhang,Wujiao Li,Rong Hou,Zhenxin Fan,Fujun Shen,Yongmei Shen,Zuoyi Jian,Lianming Du,Bisong Yue,Yun Zheng

doi:10.1371/journal.pone.0143242

Abstract

The giant panda (Ailuropoda melanoleuca) is one of the world’s most beloved endangered mammals. Although the draft genome of this species had been assembled, little was known about the composition of its microRNAs (miRNAs) or their functional profiles. Recent studies demonstrated that changes in the expression of miRNAs are associated with immunity. In this study, miRNAs were extracted from the blood of four healthy giant pandas and sequenced by Illumina next generation sequencing technology. As determined by miRNA screening, a total of 276 conserved miRNAs and 51 novel putative miRNAs candidates were detected. After differential expression analysis, we noticed that the expressions of 7 miRNAs were significantly up-regulated in young giant pandas compared with that of adults. Moreover, 2 miRNAs were up-regulated in female giant pandas and 1 in the male individuals. Target gene prediction suggested that the miRNAs of giant panda might be relevant to the expressions of 4,602 downstream genes. Subseuqently, the predicted target genes were conducted to KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis and we found that these genes were mainly involved in host immunity, including the Ras signaling pathway, the PI3K-Akt signaling pathway, and the MAPK signaling pathway. In conclusion, our results provide the first miRNA profiles of giant panda blood, and the predicted functional analyses may open an avenue for further study of giant panda immunity.

Highlights

MicroRNAs, as small non-coding (~22nt) RNAs, are key regulators of gene expression [1,2]
The number of 21nt miRNAs accounted for 26.04% in F18; The number of 22nt miRNAs accounted for 55.30% in M12; The number of 22nt accounted for 56.17% in F06; The number of 22nt accounted for 19.76% in M05
After checking the relationship between the specific miRNAs and their target genes, we found that the expressions of 52 predicted target genes had higher trend in the young group, and 51 target genes with increased expressions were observed in the adult group; No differential expressed gene was found in the 182

Summary

Introduction

MicroRNAs (miRNAs), as small non-coding (~22nt) RNAs, are key regulators of gene expression [1,2]. Precursor miRNA would form the mature functional miRNA after its stems loop structure is cut by two RNase III enzymes, Drosha and Dicer. The mature miRNAs are incorporated into the RNA-induced silencing complex (RISC), which binds to the 3’UTR protein-. MicroRNAs Profiling of Giant Panda Blood company did not have any additional role in the study design, data collection and decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section

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Conclusion