A novel cytogenetic method to image chromatin interactions at subkilobase resolution: Tn5 transposase-based fluorescence in situ hybridization.

There is an increasing interest in understanding how three-dimensional organization of the genome is regulated. Different strategies have been used to identify genome-wide chromatin interactions. However, owing to current limitations in resolving genomic contacts, visualization and validation of these genomic loci at subkilobase resolution remain unsolved to date.

Homotypic clustering of L1 and B1/Alu repeats compartmentalizes the 3D genome.

Organization of the genome into euchromatin and heterochromatin appears to be evolutionarily conserved and relatively stable during lineage differentiation. In an effort to unravel the basic principle underlying genome folding, here we focus on the genome itself and report a fundamental role for L1 (LINE1 or LINE-1) and B1/Alu retrotransposons, the most abundant subclasses of repetitive sequences, in chromatin compartmentalization. We find that homotypic clustering of L1 and B1/Alu demarcates the genome into grossly exclusive domains, and characterizes and predicts Hi-C compartments.

LncRNA Platr22 promotes super-enhancer activity and stem cell pluripotency.

Super-enhancers (SEs) comprise large clusters of enhancers, which are co-occupied by multiple lineage-specific and master transcription factors, and play pivotal roles in regulating gene expression and cell fate determination. However, it is still largely unknown whether and how SEs are regulated by the noncoding portion of the genome. Here, through genome-wide analysis, we found that long noncoding RNA (lncRNA) genes preferentially lie next to SEs.

Genomic Repeats Categorize Genes with Distinct Functions for Orchestrated Regulation.

Repetitive elements are abundantly distributed in mammalian genomes. Here, we reveal a striking association between repeat subtypes and gene function. SINE, L1, and low-complexity repeats demarcate distinct functional categories of genes and may dictate the time and level of gene expression by providing binding sites for different regulatory proteins.

Cis- and trans-acting lncRNAs in pluripotency and reprogramming.

Pervasive transcription in mammalian genomes produces thousands of long noncoding RNA (lncRNA) transcripts. Although they have been implicated in diverse biological processes, the functional relevance of most lncRNAs remains unknown. Recent studies reveal the prevalence of lncRNA-mediated cis regulation on nearby transcription.

Development of a PCR-Based Reverse Genetics System for an Attenuated Duck Tembusu Virus Strain.

The infectious disease caused by the duck Tembusu virus (DTMUV) has resulted in massive economic losses to the Chinese duck industry in China since 2010. Research on the molecular basis of DTMUV pathogenicity has been hampered by the lack of a reliable reverse genetics system for this virus. Here we developed a PCR-based reverse genetics system with high fidelity for the attenuated DTMUV strain FX2010-180P.

Divergent lncRNAs Regulate Gene Expression and Lineage Differentiation in Pluripotent Cells.

Divergent lncRNAs that are transcribed in the opposite direction to nearby protein-coding genes comprise a significant proportion (∼20%) of total lncRNAs in mammalian genomes. Through genome-wide analysis, we found that the distribution of this lncRNA class strongly correlates with essential developmental regulatory genes. In pluripotent cells, divergent lncRNAs regulate the transcription of nearby genes.

Opposing Roles for the lncRNA Haunt and Its Genomic Locus in Regulating HOXA Gene Activation during Embryonic Stem Cell Differentiation.

Long noncoding RNAs (lncRNAs) have been implicated in controlling various aspects of embryonic stem cell (ESC) biology, although the functions of specific lncRNAs, and the molecular mechanisms through which they act, remain unclear. Here, we demonstrate discrete and opposing roles for the lncRNA transcript Haunt and its genomic locus in regulating the HOXA gene cluster during ESC differentiation. Reducing or enhancing Haunt expression, with minimal disruption of the Haunt locus, led to upregulation or downregulation of HOXA genes, respectively.

Development of a live attenuated vaccine candidate against duck Tembusu viral disease.

Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that is causing massive economic loss in the Chinese duck industry. To obtain a live vaccine candidate against the disease, the DTMUV isolate FX2010 was passaged serially in chicken embryo fibroblasts (CEFs). Characterization of FX2010-180P revealed that it was unable to replicate efficiently in chicken embryonated eggs, nor intranasally infect mice or shelducks at high doses of 5.

Comparison of real-time reverse transcription loop-mediated isothermal amplification and real-time reverse transcription polymerase chain reaction for duck Tembusu virus.

Duck Tembusu virus (DTMUV) has caused huge losses to the poultry industry in China since the spring of 2010. The development of a rapid, convenient, and reliable method to diagnose this emerging duck infectious disease is critical. In the present study, a real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was compared with the real-time reverse transcription polymerase chain reaction (RT-PCR) for detection of DTMUV.

Establishing a TaqMan-based real-time PCR assay for the rapid detection and quantification of the newly emerged duck Tembusu virus.

To establish an accurate, rapid, and a quantifiable method for the detection of the newly emerged duck Tembusu virus (DTMUV) that recently caused a widespread infectious disease in ducks in China, we developed a TaqMan-based real-time PCR assay by using E gene-specific primers and a TaqMan probe. This real-time PCR assay was 100 times more sensitive than the conventional PCR. The reproducibility and specificity of the real-time PCR assay were confirmed using plasmids containing E genes or RNAs and DNAs extracted from well-known viruses causing duck diseases.

An infectious disease of ducks caused by a newly emerged Tembusu virus strain in mainland China.

During investigations into an outbreak of egg production decline, retarded growth, and even death among ducks in Southeast China, a novel Tembusu virus strain named Tembusu virus Fengxian 2010 (FX2010) was isolated. This virus replicated in embryonated chicken eggs and caused embryo death. In cross-neutralization tests, antiserum to the partial E protein of Tembusu virus Mm1775 strain neutralized FX2010, whereas antiserum to Japanese encephalitis virus did not.