Journal of Genetics and Genomics

Rising from Ashes: Non-Coding RNAs Come of Age

Zicai Liang, Xiu-Jie Wang

2013, 40(4): 141-142. doi: 10.1016/j.jgg.2013.03.007

Abstract (62) HTML PDF (1)

Abstract:

The Function of MicroRNAs in Renal Development and Pathophysiology

Liming Ma, Lianghu Qu

2013, 40(4): 143-152. doi: 10.1016/j.jgg.2013.03.002

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Abstract:
MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs that modulate diverse biological processes predominantly by translation inhibition or induction of mRNA degradation. They are important regulatory elements involved in renal physiology and pathology. Dysregulation of miRNAs disrupts early kidney development, renal progenitor cell differentiation and the maintenance of mature nephrons. miRNAs are also reported to participate in various renal diseases, including chronic kidney disease, acute kidney injury, allograft acute rejection and renal cell carcinoma. Differentially regulated miRNAs may represent innovative biomarkers for diagnosis and prognosis. Therefore, determining the roles of miRNAs in different types of renal diseases will help to clarify the pathogenesis and facilitate the development of novel therapies.

Small RNAs, RNAi and the Inheritance of Gene Silencing in Caenorhabditis elegans

Xuezhu Feng, Shouhong Guang

2013, 40(4): 153-160. doi: 10.1016/j.jgg.2012.12.007

Abstract (69) HTML PDF (1)

Abstract:
Invasive nucleic acids such as transposons and viruses usually exhibit aberrant characteristics, e.g., unpaired DNA or abnormal double-stranded RNA. Organisms employ a variety of strategies to defend themselves by distinguishing self and nonself substances and disabling these invasive nucleic acids. Furthermore, they have developed ways to remember this exposure to invaders and transmit the experience to their descendants. The mechanism underlying this inheritance has remained elusive. Recent research has shed light on the initiation and maintenance of RNA-mediated inherited gene silencing. Small regulatory RNAs play a variety of crucial roles in organisms, including gene regulation, developmental timing, antiviral defense, and genome integrity, via a process termed as RNA interference (RNAi). Recent research has revealed that small RNAs and the RNAi machinery are engaged in establishing and promoting transgenerational gene silencing. Small RNAs direct the RNAi and chromatin modification machinery to the cognate nucleic acids to regulate gene expression and epigenetic alterations. Notably, these acquired small RNAs and epigenetic changes persist and are transmitted from parents to offspring for multiple generations. Thus, RNAi is a vital determinant of the inheritance of gene silencing and acts as a driving force of evolution.

MicroRNAs and Their Cross-Talks in Plant Development

Danfeng Jin, Yue Wang, Yuhua Zhao, Ming Chen

2013, 40(4): 161-170. doi: 10.1016/j.jgg.2013.02.003

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Abstract:
Plant development is a complex process influenced by exogenous and endogenous elements. A series of postembryonic developmental events is involved to form the final architecture and contend with the changing environment. MicroRNA (miRNA) is one of endogenous non-coding RNAs, which plays an important role in plant developmental regulation. In this review, we summarized 34 miRNA families that are closely associated with plant development. Among these families, nine are expressed only in specific organs, whereas 20 families are expressed in at least two different organs. It is known that some miRNAs are expressed across most processes of plant growth, while some appear only at particular developmental stages or under special environmental conditions such as drought, waterlogging and short-day time. These miRNAs execute their diverse functions by regulating developmental gene expression levels, interacting with phytohormone signaling response, participating in the biogenesis of ta-siRNAs and affecting the production of miRNAs.

Pseudogenes: Pseudo or Real Functional Elements?

Wen Li, Wei Yang, Xiu-Jie Wang

2013, 40(4): 171-177. doi: 10.1016/j.jgg.2013.03.003

Abstract (72) HTML PDF (2)

Abstract:
Pseudogenes are genomic remnants of ancient protein-coding genes which have lost their coding potentials through evolution. Although broadly existed, pseudogenes used to be considered as junk or relics of genomes which have not drawn enough attentions of biologists until recent years. With the broad applications of high-throughput experimental techniques, growing lines of evidence have strongly suggested that some pseudogenes possess special functions, including regulating parental gene expression and participating in the regulation of many biological processes. In this review, we summarize some basic features of pseudogenes and their functions in regulating development and diseases. All of these observations indicate that pseudogenes are not purely dead fossils of genomes, but warrant further exploration in their distribution, expression regulation and functions. A new nomenclature is desirable for the currently called ‘pseudogenes’ to better describe their functions.

The Non-Coding RNA Llme23 Drives the Malignant Property of Human Melanoma Cells

Chuan-Fang Wu, Guang-Hong Tan, Cheng-Chuan Ma, Ling Li

2013, 40(4): 179-188. doi: 10.1016/j.jgg.2013.03.001

Abstract (54) HTML PDF (2)

Abstract:
Several lines of evidence support the notion that increased RNA-binding ability of polypyrimidine tract-binding (PTB) protein-associated splicing factor (PSF) and aberrant expression of long non-coding RNAs (lncRNAs) are associated with mouse and human tumors. To identify the PSF-binding lncRNA involved in human oncogenesis, we screened a nuclear RNA repertoire of human melanoma cell line, YUSAC, through RNA-SELEX affinity chromatography. A previously unreported lncRNA, termed as Llme23, was found to bind immobilized PSF resin. The specific binding of Llme23 to both recombinant and native PSF protein was confirmed in vitro and in vivo. The expression of PSF-binding Llme23 is exclusively detected in human melanoma lines. Knocking down Llme23 remarkably suppressed the malignant property of YUSAC cells, accompanied by the repressed expression of proto-oncogene Rab23. These results may indicate that Llme23 can function as an oncogenic RNA and directly associate the PSF-binding lncRNA with human melanoma.

Identifying MicroRNA and mRNA Expression Profiles in Embryonic Stem Cells Derived from Parthenogenetic, Androgenetic and Fertilized Blastocysts

Xiang-Shun Cui, Xing-Hui Shen, Shao-Chen Sun, Sun-Wha Cho, Young-Tae Heo, Yong-Kook Kang, Teruhiko Wakayama, Nam-Hyung Kim

2013, 40(4): 189-200. doi: 10.1016/j.jgg.2013.03.006

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Abstract:
MicroRNAs (miRNAs) are a class of highly conserved small non-coding RNA molecules that play a pivotal role in several cellular functions. In this study, miRNA and messenger RNA (mRNA) profiles were examined by Illumina microarray in mouse embryonic stem cells (ESCs) derived from parthenogenetic, androgenetic, and fertilized blastocysts. The global analysis of miRNA-mRNA target pairs provided insight into the role of miRNAs in gene expression. Results showed that a total of 125 miRNAs and 2394 mRNAs were differentially expressed between androgenetic ESCs (aESCs) and fertilized ESCs (fESCs), a total of 42 miRNAs and 87 mRNAs were differentially expressed between parthenogenetic ESCs (pESCs) and fESCs, and a total of 99 miRNAs and 1788 mRNAs were differentially expressed between aESCs and pESCs. In addition, a total of 575, 5 and 376 miRNA-mRNA target pairs were observed in aESCs vs. fESCs, pESCs vs. fESCs, and aESCs vs. pESCs, respectively. Furthermore, 15 known imprinted genes and 16 putative uniparentally expressed miRNAs with high expression levels were confirmed by both microarray and real-time RT-PCR. Finally, transfection of miRNA inhibitors was performed to validate the regulatory relationship between putative maternally expressed miRNAs and target mRNAs. Inhibition of miR-880 increased the expression ofPeg3, Dyrk1b, and Prrg2 mRNA, inhibition of miR-363 increased the expression of Nfat5 and Soat1 mRNA, and inhibition of miR-883b-5p increased Nfat5, Tacstd2, and Ppapdc1 mRNA. These results warrant a functional study to fully understand the underlying regulation of genomic imprinting in early embryo development.

2013 Vol. 40, No. 4