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Genes, Volume 7, Issue 12 (December 2016) – 31 articles

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1976 KiB  
Review
The Causes and Consequences of Topological Stress during DNA Replication
by Andrea Keszthelyi, Nicola E. Minchell and Jonathan Baxter
Genes 2016, 7(12), 134; https://doi.org/10.3390/genes7120134 - 21 Dec 2016
Cited by 53 | Viewed by 9054
Abstract
The faithful replication of sister chromatids is essential for genomic integrity in every cell division. The replication machinery must overcome numerous difficulties in every round of replication, including DNA topological stress. Topological stress arises due to the double-stranded helical nature of DNA. When [...] Read more.
The faithful replication of sister chromatids is essential for genomic integrity in every cell division. The replication machinery must overcome numerous difficulties in every round of replication, including DNA topological stress. Topological stress arises due to the double-stranded helical nature of DNA. When the strands are pulled apart for replication to occur, the intertwining of the double helix must also be resolved or topological stress will arise. This intrinsic problem is exacerbated by specific chromosomal contexts encountered during DNA replication. The convergence of two replicons during termination, the presence of stable protein-DNA complexes and active transcription can all lead to topological stresses being imposed upon DNA replication. Here we describe how replication forks respond to topological stress by replication fork rotation and fork reversal. We also discuss the genomic contexts where topological stress is likely to occur in eukaryotes, focusing on the contribution of transcription. Finally, we describe how topological stress, and the ways forks respond to it, may contribute to genomic instability in cells. Full article
(This article belongs to the Special Issue DNA Replication Controls)
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Article
Stem-Loop RT-qPCR as an Efficient Tool for the Detection and Quantification of Small RNAs in Giardia lamblia
by Jaime Marcial-Quino, Saúl Gómez-Manzo, Francisco Fierro, America Vanoye-Carlo, Yadira Rufino-González, Edgar Sierra-Palacios, Adriana Castillo-Villanueva, Rosa Angélica Castillo-Rodríguez, Eduardo Rodríguez-Bustamante, Roberto Arreguin-Espinosa and Horacio Reyes-Vivas
Genes 2016, 7(12), 131; https://doi.org/10.3390/genes7120131 - 20 Dec 2016
Cited by 15 | Viewed by 10637
Abstract
Stem-loop quantitative reverse transcription PCR (RT-qPCR) is a molecular technique used for identification and quantification of individual small RNAs in cells. In this work, we used a Universal ProbeLibrary (UPL)-based design to detect—in a rapid, sensitive, specific, and reproducible way—the small nucleolar RNA [...] Read more.
Stem-loop quantitative reverse transcription PCR (RT-qPCR) is a molecular technique used for identification and quantification of individual small RNAs in cells. In this work, we used a Universal ProbeLibrary (UPL)-based design to detect—in a rapid, sensitive, specific, and reproducible way—the small nucleolar RNA (snoRNA) GlsR17 and its derived miRNA (miR2) of Giardia lamblia using a stem-loop RT-qPCR approach. Both small RNAs could be isolated from both total RNA and small RNA samples. Identification of the two small RNAs was carried out by sequencing the PCR-amplified small RNA products upon ligation into the pJET1.2/blunt vector. GlsR17 is constitutively expressed during the 72 h cultures of trophozoites, while the mature miR2 is present in 2-fold higher abundance during the first 48 h than at 72 h. Because it has been suggested that miRNAs in G. lamblia have an important role in the regulation of gene expression, the use of the stem-loop RT-qPCR method could be valuable for the study of miRNAs of G. lamblia. This methodology will be a powerful tool for studying gene regulation in G. lamblia, and will help to better understand the features and functions of these regulatory molecules and how they work within the RNA interference (RNAi) pathway in G. lamblia. Full article
(This article belongs to the Section Molecular Genetics and Genomics)
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Article
Hybridization Capture-Based Next-Generation Sequencing to Evaluate Coding Sequence and Deep Intronic Mutations in the NF1 Gene
by Karin Soares Cunha, Nathalia Silva Oliveira, Anna Karoline Fausto, Carolina Cruz De Souza, Audrey Gros, Thomas Bandres, Yamina Idrissi, Jean-Philippe Merlio, Rodrigo Soares De Moura Neto, Rosane Silva, Mauro Geller and David Cappellen
Genes 2016, 7(12), 133; https://doi.org/10.3390/genes7120133 - 17 Dec 2016
Cited by 14 | Viewed by 6532
Abstract
Neurofibromatosis 1 (NF1) is one of the most common genetic disorders and is caused by mutations in the NF1 gene. NF1 gene mutational analysis presents a considerable challenge because of its large size, existence of highly homologous pseudogenes located throughout the human genome, [...] Read more.
Neurofibromatosis 1 (NF1) is one of the most common genetic disorders and is caused by mutations in the NF1 gene. NF1 gene mutational analysis presents a considerable challenge because of its large size, existence of highly homologous pseudogenes located throughout the human genome, absence of mutational hotspots, and diversity of mutations types, including deep intronic splicing mutations. We aimed to evaluate the use of hybridization capture-based next-generation sequencing to screen coding and noncoding NF1 regions. Hybridization capture-based next-generation sequencing, with genomic DNA as starting material, was used to sequence the whole NF1 gene (exons and introns) from 11 unrelated individuals and 1 relative, who all had NF1. All of them met the NF1 clinical diagnostic criteria. We showed a mutation detection rate of 91% (10 out of 11). We identified eight recurrent and two novel mutations, which were all confirmed by Sanger methodology. In the Sanger sequencing confirmation, we also included another three relatives with NF1. Splicing alterations accounted for 50% of the mutations. One of them was caused by a deep intronic mutation (c.1260 + 1604A > G). Frameshift truncation and missense mutations corresponded to 30% and 20% of the pathogenic variants, respectively. In conclusion, we show the use of a simple and fast approach to screen, at once, the entire NF1 gene (exons and introns) for different types of pathogenic variations, including the deep intronic splicing mutations. Full article
(This article belongs to the Section Human Genomics and Genetic Diseases)
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Communication
Mutant CAG Repeats Effectively Targeted by RNA Interference in SCA7 Cells
by Agnieszka Fiszer, Joanna P. Wroblewska, Bartosz M. Nowak and Wlodzimierz J. Krzyzosiak
Genes 2016, 7(12), 132; https://doi.org/10.3390/genes7120132 - 17 Dec 2016
Cited by 13 | Viewed by 4676
Abstract
Spinocerebellar ataxia type 7 (SCA7) is a human neurodegenerative polyglutamine (polyQ) disease caused by a CAG repeat expansion in the open reading frame of the ATXN7 gene. The allele-selective silencing of mutant transcripts using a repeat-targeting strategy has previously been used for several [...] Read more.
Spinocerebellar ataxia type 7 (SCA7) is a human neurodegenerative polyglutamine (polyQ) disease caused by a CAG repeat expansion in the open reading frame of the ATXN7 gene. The allele-selective silencing of mutant transcripts using a repeat-targeting strategy has previously been used for several polyQ diseases. Herein, we demonstrate that the selective targeting of a repeat tract in a mutant ATXN7 transcript by RNA interference is a feasible approach and results in an efficient decrease of mutant ataxin-7 protein in patient-derived cells. Oligonucleotides (ONs) containing specific base substitutions cause the downregulation of the ATXN7 mutant allele together with the upregulation of its normal allele. The A2 ON shows high allele selectivity at a broad range of concentrations and also restores UCHL1 expression, which is downregulated in SCA7. Full article
(This article belongs to the Special Issue RNA Interference 2016)
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Review
Dysregulated MicroRNA Expression Profiles and Potential Cellular, Circulating and Polymorphic Biomarkers in Non-Hodgkin Lymphoma
by Gabrielle Bradshaw, Heidi G. Sutherland, Larisa M. Haupt and Lyn R. Griffiths
Genes 2016, 7(12), 130; https://doi.org/10.3390/genes7120130 - 17 Dec 2016
Cited by 17 | Viewed by 5044
Abstract
A large number of studies have focused on identifying molecular biomarkers, including microRNAs (miRNAs) to aid in the diagnosis and prognosis of the most common subtypes of non-Hodgkin lymphoma (NHL), Diffuse Large B-cell Lymphoma and Follicular Lymphoma. NHL is difficult to diagnose and [...] Read more.
A large number of studies have focused on identifying molecular biomarkers, including microRNAs (miRNAs) to aid in the diagnosis and prognosis of the most common subtypes of non-Hodgkin lymphoma (NHL), Diffuse Large B-cell Lymphoma and Follicular Lymphoma. NHL is difficult to diagnose and treat with many cases becoming resistant to chemotherapy, hence the need to identify improved biomarkers to aid in both diagnosis and treatment modalities. This review summarises more recent research on the dysregulated miRNA expression profiles found in NHL, as well as the regulatory role and biomarker potential of cellular and circulating miRNAs found in tissue and serum, respectively. In addition, the emerging field of research focusing on miRNA single nucleotide polymorphisms (miRSNPs) in genes of the miRNA biogenesis pathway, in miRNA genes themselves, and in their target sites may provide new insights on gene expression changes in these genes. These miRSNPs may impact miRNA networks and have been shown to play a role in a host of different cancer types including haematological malignancies. With respect to NHL, a number of SNPs in miRNA-binding sites in target genes have been shown to be associated with overall survival. Full article
(This article belongs to the Special Issue microRNAs and Other Non-Coding RNAs in Human Diseases)
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Review
Functions of the RNA Editing Enzyme ADAR1 and Their Relevance to Human Diseases
by Chunzi Song, Masayuki Sakurai, Yusuke Shiromoto and Kazuko Nishikura
Genes 2016, 7(12), 129; https://doi.org/10.3390/genes7120129 - 17 Dec 2016
Cited by 56 | Viewed by 11958
Abstract
Adenosine deaminases acting on RNA (ADARs) convert adenosine to inosine in double-stranded RNA (dsRNA). Among the three types of mammalian ADARs, ADAR1 has long been recognized as an essential enzyme for normal development. The interferon-inducible ADAR1p150 is involved in immune responses to both [...] Read more.
Adenosine deaminases acting on RNA (ADARs) convert adenosine to inosine in double-stranded RNA (dsRNA). Among the three types of mammalian ADARs, ADAR1 has long been recognized as an essential enzyme for normal development. The interferon-inducible ADAR1p150 is involved in immune responses to both exogenous and endogenous triggers, whereas the functions of the constitutively expressed ADAR1p110 are variable. Recent findings that ADAR1 is involved in the recognition of self versus non-self dsRNA provide potential explanations for its links to hematopoiesis, type I interferonopathies, and viral infections. Editing in both coding and noncoding sequences results in diseases ranging from cancers to neurological abnormalities. Furthermore, editing of noncoding sequences, like microRNAs, can regulate protein expression, while editing of Alu sequences can affect translational efficiency and editing of proximal sequences. Novel identifications of long noncoding RNA and retrotransposons as editing targets further expand the effects of A-to-I editing. Besides editing, ADAR1 also interacts with other dsRNA-binding proteins in editing-independent manners. Elucidating the disease-specific patterns of editing and/or ADAR1 expression may be useful in making diagnoses and prognoses. In this review, we relate the mechanisms of ADAR1′s actions to its pathological implications, and suggest possible mechanisms for the unexplained associations between ADAR1 and human diseases. Full article
(This article belongs to the Special Issue RNA Editing)
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Article
Evaluation of Methylation Biomarkers for Detection of Circulating Tumor DNA and Application to Colorectal Cancer
by Susan M. Mitchell, Thu Ho, Glenn S. Brown, Rohan T. Baker, Melissa L. Thomas, Aidan McEvoy, Zheng-Zhou Xu, Jason P. Ross, Trevor J. Lockett, Graeme P. Young, Lawrence C. LaPointe, Susanne K. Pedersen and Peter L. Molloy
Genes 2016, 7(12), 125; https://doi.org/10.3390/genes7120125 - 15 Dec 2016
Cited by 49 | Viewed by 8683
Abstract
Solid tumors shed DNA into circulation, and there is growing evidence that the detection of circulating tumor DNA (ctDNA) has broad clinical utility, including monitoring of disease, prognosis, response to chemotherapy and tracking tumor heterogeneity. The appearance of ctDNA in the circulating cell-free [...] Read more.
Solid tumors shed DNA into circulation, and there is growing evidence that the detection of circulating tumor DNA (ctDNA) has broad clinical utility, including monitoring of disease, prognosis, response to chemotherapy and tracking tumor heterogeneity. The appearance of ctDNA in the circulating cell-free DNA (ccfDNA) isolated from plasma or serum is commonly detected by identifying tumor-specific features such as insertions, deletions, mutations and/or aberrant methylation. Methylation is a normal cell regulatory event, and since the majority of ccfDNA is derived from white blood cells (WBC), it is important that tumour-specific DNA methylation markers show rare to no methylation events in WBC DNA. We have used a novel approach for assessment of low levels of DNA methylation in WBC DNA. DNA methylation in 29 previously identified regions (residing in 17 genes) was analyzed in WBC DNA and eight differentially-methylated regions (DMRs) were taken through to testing in clinical samples using methylation specific PCR assays. DMRs residing in four genes, BCAT1, GRASP, IKZF1 and IRF4, exhibited low positivity, 3.5% to 7%, in the plasma of colonoscopy-confirmed healthy subjects, with the sensitivity for detection of ctDNA in colonoscopy-confirmed patients with colorectal cancer being 65%, 54.5%, 67.6% and 59% respectively. Full article
(This article belongs to the Special Issue Cancer Genetics)
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Article
Electroporation of DNA into Physarum polycephalum Mitochondria: Effects on Transcription and RNA Editing in Isolated Organelles
by Jonatha M. Gott, Gregory M. Naegele and Scott J. Howell
Genes 2016, 7(12), 128; https://doi.org/10.3390/genes7120128 - 14 Dec 2016
Cited by 3 | Viewed by 4940
Abstract
Mitochondrial RNAs in the acellular slime mold Physarum polycephalum contain nucleotides that are not encoded in the mitochondrial genes from which they are transcribed. These site-specific changes are quite extensive, comprising ~4% of the residues within mRNAs and ~2% of rRNAs and tRNAs. [...] Read more.
Mitochondrial RNAs in the acellular slime mold Physarum polycephalum contain nucleotides that are not encoded in the mitochondrial genes from which they are transcribed. These site-specific changes are quite extensive, comprising ~4% of the residues within mRNAs and ~2% of rRNAs and tRNAs. These “extra” nucleotides are added co-transcriptionally, but the means by which this is accomplished have not been elucidated. The cox1 mRNA also contains four sites of C to U changes, which occur post-transcriptionally, most likely via targeted deamination. The currently available in vitro systems for studying P. polycephalum editing are limited in that the template is the entire ~63,000 bp mitochondrial genome. This presents a significant challenge when trying to define the signals that specify editing sites. In an attempt to overcome this issue, a method for introducing DNA into isolated P. polycephalum mitochondria via electroporation has been developed. Exogenous DNA is expressed, but the transcripts synthesized from these templates are not edited under the conditions tested. However, transcripts derived from the mitochondrial genome are accurately edited after electroporation, indicating that the editing machinery is still functional. These findings suggest that this method may ultimately provide a feasible approach to elucidating editing signals. Full article
(This article belongs to the Special Issue RNA Editing)
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Article
New Cross-Talk Layer between Ultraconserved Non-Coding RNAs, MicroRNAs and Polycomb Protein YY1 in Bladder Cancer
by Sara Terreri, Montano Durso, Vincenza Colonna, Alessandra Romanelli, Daniela Terracciano, Matteo Ferro, Sisto Perdonà, Luigi Castaldo, Ferdinando Febbraio, Filomena De Nigris and Amelia Cimmino
Genes 2016, 7(12), 127; https://doi.org/10.3390/genes7120127 - 14 Dec 2016
Cited by 27 | Viewed by 5107
Abstract
MicroRNAs (miRNAs) are highly conserved elements in mammals, and exert key regulatory functions. Growing evidence shows that miRNAs can interact with another class of non-coding RNAs, so-called transcribed ultraconserved regions (T-UCRs), which take part in transcriptional, post-transcriptional and epigenetic regulation processes. We report [...] Read more.
MicroRNAs (miRNAs) are highly conserved elements in mammals, and exert key regulatory functions. Growing evidence shows that miRNAs can interact with another class of non-coding RNAs, so-called transcribed ultraconserved regions (T-UCRs), which take part in transcriptional, post-transcriptional and epigenetic regulation processes. We report here the interaction of miRNAs and T-UCRs as a network modulating the availability of these non-coding RNAs in bladder cancer cells. In our cell system, antagomiR-596 increased the expression of T-UCR 201+. Moreover, T-UCR 8+ silencing increased miR-596 expression, which in turn reduced total T-UCR 283+, showing that the perturbation of one element in this network changes the expression of other interactors. In addition, we identify the polycomb protein Yin Yang 1 (YY1) as mediator of binding between miR-596 and T-UCR 8+. These new findings describe for the first time a network between T-UCRs, miRNAs and YY1 protein, highlighting the existence of an additional layer of gene expression regulation. Full article
(This article belongs to the Special Issue microRNAs and Other Non-Coding RNAs in Human Diseases)
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Review
Regulation of Pseudomonas aeruginosa Virulence by Distinct Iron Sources
by Alexandria A. Reinhart and Amanda G. Oglesby-Sherrouse
Genes 2016, 7(12), 126; https://doi.org/10.3390/genes7120126 - 14 Dec 2016
Cited by 44 | Viewed by 9479
Abstract
Pseudomonas aeruginosa is a ubiquitous environmental bacterium and versatile opportunistic pathogen. Like most other organisms, P. aeruginosa requires iron for survival, yet iron rapidly reacts with oxygen and water to form stable ferric (FeIII) oxides and hydroxides, limiting its availability to living organisms. [...] Read more.
Pseudomonas aeruginosa is a ubiquitous environmental bacterium and versatile opportunistic pathogen. Like most other organisms, P. aeruginosa requires iron for survival, yet iron rapidly reacts with oxygen and water to form stable ferric (FeIII) oxides and hydroxides, limiting its availability to living organisms. During infection, iron is also sequestered by the host innate immune system, further limiting its availability. P. aeruginosa’s capacity to cause disease in diverse host environments is due to its ability to scavenge iron from a variety of host iron sources. Work over the past two decades has further shown that different iron sources can affect the expression of distinct virulence traits. This review discusses how the individual components of P. aeruginosa’s iron regulatory network allow this opportunist to adapt to a multitude of host environments during infection. Full article
(This article belongs to the Special Issue Virulence Gene Regulation in Bacteria)
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Article
microRNA Expression in Sentinel Nodes from Progressing Melanoma Patients Identifies Networks Associated with Dysfunctional Immune Response
by Viviana Vallacchi, Chiara Camisaschi, Matteo Dugo, Elisabetta Vergani, Paola Deho, Ambra Gualeni, Veronica Huber, Annunziata Gloghini, Andrea Maurichi, Mario Santinami, Marialuisa Sensi, Chiara Castelli, Licia Rivoltini and Monica Rodolfo
Genes 2016, 7(12), 124; https://doi.org/10.3390/genes7120124 - 14 Dec 2016
Cited by 8 | Viewed by 5530
Abstract
Sentinel node biopsy (SNB) is a main staging biomarker in melanoma and is the first lymph node to drain the tumor, thus representing the immunological site where anti-tumor immune dysfunction is established and where potential prognostic immune markers can be identified. Here we [...] Read more.
Sentinel node biopsy (SNB) is a main staging biomarker in melanoma and is the first lymph node to drain the tumor, thus representing the immunological site where anti-tumor immune dysfunction is established and where potential prognostic immune markers can be identified. Here we analyzed microRNA (miR) profiles in archival tumor-positive SNBs derived from melanoma patients with different outcomes and performed an integrated analysis of transcriptional data to identify deregulated immune signaling networks. Twenty-six miRs were differentially expressed in melanoma-positive SNB samples between patients with disease progression and non-progressing patients, the majority being previously reported in the regulation of immune responses. A significant variation in miR expression levels was confirmed in an independent set of SNB samples. Integrated information from genome-wide transcriptional profiles and in vitro assessment in immune cells led to the identification of miRs associated with the regulation of the TNF receptor superfamily member 8 (TNFRSF8) gene encoding the CD30 receptor, a marker increased in lymphocytes of melanoma patients with progressive disease. These findings indicate that miRs are involved in the regulation of pathways leading to immune dysfunction in the sentinel node and may provide valuable markers for developing prognostic molecular signatures for the identification of stage III melanoma patients at risk of recurrence. Full article
(This article belongs to the Special Issue microRNAs and Other Non-Coding RNAs in Human Diseases)
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Review
Study of the Genetic Etiology of Primary Ovarian Insufficiency: FMR1 Gene
by Maitane Barasoain, Gorka Barrenetxea, Iratxe Huerta, Mercedes Télez, Begoña Criado and Isabel Arrieta
Genes 2016, 7(12), 123; https://doi.org/10.3390/genes7120123 - 13 Dec 2016
Cited by 30 | Viewed by 5288
Abstract
Menopause is a period of women’s life characterized by the cessation of menses in a definitive way. The mean age for menopause is approximately 51 years. Primary ovarian insufficiency (POI) refers to ovarian dysfunction defined as irregular menses and elevated gonadotrophin levels before [...] Read more.
Menopause is a period of women’s life characterized by the cessation of menses in a definitive way. The mean age for menopause is approximately 51 years. Primary ovarian insufficiency (POI) refers to ovarian dysfunction defined as irregular menses and elevated gonadotrophin levels before or at the age of 40 years. The etiology of POI is unknown but several genes have been reported as being of significance. The fragile X mental retardation 1 gene (FMR1) is one of the most important genes associated with POI. The FMR1 gene contains a highly polymorphic CGG repeat in the 5′ untranslated region of exon 1. Four allelic forms have been defined with respect to CGG repeat length and instability during transmission. Normal (5–44 CGG) alleles are usually transmitted from parent to offspring in a stable manner. The full mutation form consists of over 200 repeats, which induces hypermethylation of the FMR1 gene promoter and the subsequent silencing of the gene, associated with Fragile X Syndrome (FXS). Finally, FMR1 intermediate (45–54 CGG) and premutation (55–200 CGG) alleles have been principally associated with two phenotypes, fragile X tremor ataxia syndrome (FXTAS) and fragile X primary ovarian insufficiency (FXPOI). Full article
(This article belongs to the Special Issue Fragile X Syndrome)
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Review
Detection and Quantification of the Fragile X Mental Retardation Protein 1 (FMRP)
by Giuseppe LaFauci, Tatyana Adayev, Richard Kascsak and W. Ted Brown
Genes 2016, 7(12), 121; https://doi.org/10.3390/genes7120121 - 09 Dec 2016
Cited by 15 | Viewed by 7610
Abstract
The final product of FMR1 gene transcription, Fragile X Mental Retardation Protein 1 (FMRP), is an RNA binding protein that acts as a repressor of translation. FMRP is expressed in several tissues and plays important roles in neurogenesis, synaptic plasticity, and ovarian functions [...] Read more.
The final product of FMR1 gene transcription, Fragile X Mental Retardation Protein 1 (FMRP), is an RNA binding protein that acts as a repressor of translation. FMRP is expressed in several tissues and plays important roles in neurogenesis, synaptic plasticity, and ovarian functions and has been implicated in a number of neuropsychological disorders. The loss of FMRP causes Fragile X Syndrome (FXS). In most cases, FXS is due to large expansions of a CGG repeat in FMR1—normally containing 6–54 repeats—to over 200 CGGs and identified as full mutation (FM). Hypermethylation of the repeat induces FMR1 silencing and lack of FMRP expression in FM male. Mosaic FM males express low levels of FMRP and present a less severe phenotype that inversely correlates with FMRP levels. Carriers of pre-mutations (55–200 CGG) show increased mRNA, and normal to reduced FMRP levels. Alternative splicing of FMR1 mRNA results in 24 FMRP predicted isoforms whose expression are tissues and developmentally regulated. Here, we summarize the approaches used by several laboratories including our own to (a) detect and estimate the amount of FMRP in different tissues, developmental stages and various pathologies; and (b) to accurately quantifying FMRP for a direct diagnosis of FXS in adults and newborns. Full article
(This article belongs to the Special Issue Fragile X Syndrome)
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Article
Host-Derived Artificial MicroRNA as an Alternative Method to Improve Soybean Resistance to Soybean Cyst Nematode
by Bin Tian, Jiarui Li, Thomas R. Oakley, Timothy C. Todd and Harold N. Trick
Genes 2016, 7(12), 122; https://doi.org/10.3390/genes7120122 - 08 Dec 2016
Cited by 22 | Viewed by 5420
Abstract
The soybean cyst nematode (SCN), Heterodera glycines, is one of the most important pests limiting soybean production worldwide. Novel approaches to managing this pest have focused on gene silencing of target nematode sequences using RNA interference (RNAi). With the discovery of endogenous [...] Read more.
The soybean cyst nematode (SCN), Heterodera glycines, is one of the most important pests limiting soybean production worldwide. Novel approaches to managing this pest have focused on gene silencing of target nematode sequences using RNA interference (RNAi). With the discovery of endogenous microRNAs as a mode of gene regulation in plants, artificial microRNA (amiRNA) methods have become an alternative method for gene silencing, with the advantage that they can lead to more specific silencing of target genes than traditional RNAi vectors. To explore the application of amiRNAs for improving soybean resistance to SCN, three nematode genes (designated as J15, J20, and J23) were targeted using amiRNA vectors. The transgenic soybean hairy roots, transformed independently with these three amiRNA vectors, showed significant reductions in SCN population densities in bioassays. Expression of the targeted genes within SCN eggs were downregulated in populations feeding on transgenic hairy roots. Our results provide evidence that host-derived amiRNA methods have great potential to improve soybean resistance to SCN. This approach should also limit undesirable phenotypes associated with off-target effects, which is an important consideration for commercialization of transgenic crops. Full article
(This article belongs to the Special Issue RNA Interference 2016)
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Article
The Virulence Regulator Rns Activates the Expression of CS14 Pili
by Maria Del Rocio Bodero and George Patrick Munson
Genes 2016, 7(12), 120; https://doi.org/10.3390/genes7120120 - 08 Dec 2016
Cited by 7 | Viewed by 3867
Abstract
Although many viral and bacterial pathogens cause diarrhea, enterotoxigenic E. coli (ETEC) is one of the most frequently encountered in impoverished regions where it is estimated to kill between 300,000 and 700,000 children and infants annually. Critical ETEC virulence factors include pili which [...] Read more.
Although many viral and bacterial pathogens cause diarrhea, enterotoxigenic E. coli (ETEC) is one of the most frequently encountered in impoverished regions where it is estimated to kill between 300,000 and 700,000 children and infants annually. Critical ETEC virulence factors include pili which mediate the attachment of the pathogen to receptors in the intestinal lumen. In this study we show that the ETEC virulence regulator Rns positively regulates the expression of CS14 pili. Three Rns binding sites were identified upstream of the CS14 pilus promoter centered at −34.5, −80.5, and −155.5 relative to the Rns-dependent transcription start site. Mutagenesis of the promoter proximal site significantly decreased expression from the CS14 promoter. In contrast, the contribution of Rns bound at the promoter distal site was negligible and largely masked by occupancy of the promoter proximal site. Unexpectedly, Rns bound at the site centered at −80.5 had a slight but statistically significant inhibitory effect upon the pilin promoter. Nevertheless, this weak inhibitory effect was not sufficient to overcome the substantial promoter activation from Rns bound to the promoter proximal site. Thus, CS14 pili belong to a group of pili that depend upon Rns for their expression. Full article
(This article belongs to the Special Issue Virulence Gene Regulation in Bacteria)
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Review
Achieving HIV-1 Control through RNA-Directed Gene Regulation
by Vera Klemm, Jye Mitchell, Christina Cortez-Jugo, Francesca Cavalieri, Geoff Symonds, Frank Caruso, Anthony Dominic Kelleher and Chantelle Ahlenstiel
Genes 2016, 7(12), 119; https://doi.org/10.3390/genes7120119 - 07 Dec 2016
Cited by 9 | Viewed by 7129
Abstract
HIV-1 infection has been transformed by combined anti-retroviral therapy (ART), changing a universally fatal infection into a controllable infection. However, major obstacles for an HIV-1 cure exist. The HIV latent reservoir, which exists in resting CD4+ T cells, is not impacted by ART, [...] Read more.
HIV-1 infection has been transformed by combined anti-retroviral therapy (ART), changing a universally fatal infection into a controllable infection. However, major obstacles for an HIV-1 cure exist. The HIV latent reservoir, which exists in resting CD4+ T cells, is not impacted by ART, and can reactivate when ART is interrupted or ceased. Additionally, multi-drug resistance can arise. One alternate approach to conventional HIV-1 drug treatment that is being explored involves gene therapies utilizing RNA-directed gene regulation. Commonly known as RNA interference (RNAi), short interfering RNA (siRNA) induce gene silencing in conserved biological pathways, which require a high degree of sequence specificity. This review will provide an overview of the silencing pathways, the current RNAi technologies being developed for HIV-1 gene therapy, current clinical trials, and the challenges faced in progressing these treatments into clinical trials. Full article
(This article belongs to the Special Issue RNA Interference 2016)
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Communication
New Oligonucleotide Probes for ND-FISH Analysis to Identify Barley Chromosomes and to Investigate Polymorphisms of Wheat Chromosomes
by Shuyao Tang, Ling Qiu, Zhiqiang Xiao, Shulan Fu and Zongxiang Tang
Genes 2016, 7(12), 118; https://doi.org/10.3390/genes7120118 - 05 Dec 2016
Cited by 39 | Viewed by 6525
Abstract
Oligonucleotide probes that can be used for non-denaturing fluorescence in situ hybridization (ND-FISH) analysis are convenient tools for identifying chromosomes of wheat (Triticum aestivum L.) and its relatives. New oligonucleotide probes, Oligo-HvT01, Oligo-pTa71-1, Oligo-s120.1, Oligo-s120.2, Oligo-s120.3, Oligo-275.1, Oligo-275.2, Oligo-k566 and Oligo-713, were [...] Read more.
Oligonucleotide probes that can be used for non-denaturing fluorescence in situ hybridization (ND-FISH) analysis are convenient tools for identifying chromosomes of wheat (Triticum aestivum L.) and its relatives. New oligonucleotide probes, Oligo-HvT01, Oligo-pTa71-1, Oligo-s120.1, Oligo-s120.2, Oligo-s120.3, Oligo-275.1, Oligo-275.2, Oligo-k566 and Oligo-713, were designed based on the repetitive sequences HVT01, pTa71, pTa-s120, pTa-275, pTa-k566 and pTa-713. All these probes can be used for ND-FISH analysis and some of them can be used to detect polymorphisms of wheat chromosomes. Probes Oligo-HvT01, Oligo-pTa71-1, Oligo-s120.3, Oligo-275.1, Oligo-k566 and Oligo-713 can, respectively, replace the roles of their original sequences to identify chromosomes of some barley (Hordeum vulgare ssp. vulgare) and the common wheat variety Chinese Spring. Oligo-s120.1, Oligo-s120.2 and Oligo-275.2 produced different hybridization patterns from the ones generated by their original sequences. In addition, Oligo-s120.1, Oligo-s120.2 and Oligo-s120.3, which were derived from pTa-s120, revealed different signal patterns. Likewise, Oligo-275.1 and Oligo-275.2, which were derived from pTa-275, also displayed different hybridization patterns. These results imply that differently arranged or altered structural statuses of tandem repeats might exist on different chromosome regions. These new oligonucleotide probes provide extra convenience for identifying some wheat and barley chromosomes, and they can display polymorphisms of wheat chromosomes. Full article
(This article belongs to the Section Population and Evolutionary Genetics and Genomics)
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Communication
Deficiency in the Ubiquitin Conjugating Enzyme UBE2A in Alzheimer’s Disease (AD) is Linked to Deficits in a Natural Circular miRNA-7 Sponge (circRNA; ciRS-7)
by Yuhai Zhao, Peter N. Alexandrov, Vivian Jaber and Walter J. Lukiw
Genes 2016, 7(12), 116; https://doi.org/10.3390/genes7120116 - 05 Dec 2016
Cited by 249 | Viewed by 9496
Abstract
Our understanding of the highly specialized functions for small non-coding single-stranded RNA (ssRNA) in the transcriptome of the human central nervous system (CNS) continues to evolve. Circular RNAs (circRNAs), a recently discovered class of ssRNA enriched in the brain and retina, are extremely [...] Read more.
Our understanding of the highly specialized functions for small non-coding single-stranded RNA (ssRNA) in the transcriptome of the human central nervous system (CNS) continues to evolve. Circular RNAs (circRNAs), a recently discovered class of ssRNA enriched in the brain and retina, are extremely stable and intrinsically resilient to degradation by exonuclease. Conventional methods of ssRNA, microRNA (miRNA), or messenger RNA (mRNA) detection and quantitation requiring free ribonucleotide ends may have considerably underestimated the quantity and significance of CNS circRNA in the CNS. Highly-specific small ssRNAs, such as the ~23 nucleotide (nt) Homo sapien microRNA-7 (hsa-miRNA-7; chr 9q21.32), are not only abundant in the human limbic system but are, in addition, associated with a ~1400 nt circRNA for miRNA-7 (ciRS-7) in the same anatomical region. Structurally, ciRS-7 contains about ~70 tandem anti-miRNA-7 sequences and acts as an endogenous, anti-complementary miRNA-7 “sponge” that attracts, binds, and, hence, quenches, natural miRNA-7 functions. Using a combination of DNA and miRNA array technologies, enhanced LED-Northern and Western blot hybridization, and the magnesium-dependent exoribonuclease and circRNA-sensitive probe RNaseR, here we provide evidence of a significantly misregulated ciRS-7-miRNA-7-UBE2A circuit in sporadic Alzheimer’s disease (AD) neocortex (Brodmann A22) and hippocampal CA1. Deficits in ciRS-7-mediated “sponging events”, resulting in excess ambient miRNA-7 appear to drive the selective down-regulation in the expression of miRNA-7-sensitive mRNA targets, such as that encoding the ubiquitin conjugating enzyme E2A (UBE2A; chr Xq24). UBE2A, which normally serves as a central effector in the ubiquitin-26S proteasome system, coordinates the clearance of amyloid peptides via proteolysis, is known to be depleted in sporadic AD brain and, hence, contributes to amyloid accumulation and the formation of senile plaque deposits. Dysfunction of circRNA-miRNA-mRNA regulatory systems appears to represent another important layer of epigenetic control over pathogenic gene expression programs in the human CNS that are targeted by the sporadic AD process. Full article
(This article belongs to the Special Issue microRNAs and Other Non-Coding RNAs in Human Diseases)
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Review
Cord Blood DNA Methylation Biomarkers for Predicting Neurodevelopmental Outcomes
by Nicolette A. Hodyl, Claire T. Roberts and Tina Bianco-Miotto
Genes 2016, 7(12), 117; https://doi.org/10.3390/genes7120117 - 03 Dec 2016
Cited by 22 | Viewed by 5959
Abstract
Adverse environmental exposures in pregnancy can significantly alter the development of the fetus resulting in impaired child neurodevelopment. Such exposures can lead to epigenetic alterations like DNA methylation, which may be a marker of poor cognitive, motor and behavioral outcomes in the infant. [...] Read more.
Adverse environmental exposures in pregnancy can significantly alter the development of the fetus resulting in impaired child neurodevelopment. Such exposures can lead to epigenetic alterations like DNA methylation, which may be a marker of poor cognitive, motor and behavioral outcomes in the infant. Here we review studies that have assessed DNA methylation in cord blood following maternal exposures that may impact neurodevelopment of the child. We also highlight some key studies to illustrate the potential for DNA methylation to successfully identify infants at risk for poor outcomes. While the current evidence is limited, in that observations to date are largely correlational, in time and with larger cohorts analyzed and longer term follow-up completed, we may be able to develop epigenetic biomarkers that not only indicate adverse early life exposures but can also be used to identify individuals likely to be at an increased risk of impaired neurodevelopment even in the absence of detailed information regarding prenatal environment. Full article
(This article belongs to the Special Issue Epigenetic Biomarkers)
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Review
A Review of Computational Methods for Finding Non-Coding RNA Genes
by Qaisar Abbas, Syed Mansoor Raza, Azizuddin Ahmed Biyabani and Muhammad Arfan Jaffar
Genes 2016, 7(12), 113; https://doi.org/10.3390/genes7120113 - 03 Dec 2016
Cited by 18 | Viewed by 6870
Abstract
Finding non-coding RNA (ncRNA) genes has emerged over the past few years as a cutting-edge trend in bioinformatics. There are numerous computational intelligence (CI) challenges in the annotation and interpretation of ncRNAs because it requires a domain-related expert knowledge in CI techniques. Moreover, [...] Read more.
Finding non-coding RNA (ncRNA) genes has emerged over the past few years as a cutting-edge trend in bioinformatics. There are numerous computational intelligence (CI) challenges in the annotation and interpretation of ncRNAs because it requires a domain-related expert knowledge in CI techniques. Moreover, there are many classes predicted yet not experimentally verified by researchers. Recently, researchers have applied many CI methods to predict the classes of ncRNAs. However, the diverse CI approaches lack a definitive classification framework to take advantage of past studies. A few review papers have attempted to summarize CI approaches, but focused on the particular methodological viewpoints. Accordingly, in this article, we summarize in greater detail than previously available, the CI techniques for finding ncRNAs genes. We differentiate from the existing bodies of research and discuss concisely the technical merits of various techniques. Lastly, we review the limitations of ncRNA gene-finding CI methods with a point-of-view towards the development of new computational tools. Full article
(This article belongs to the Special Issue microRNAs and Other Non-Coding RNAs in Human Diseases)
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Article
Phylogenetic Relationships of the Fern Cyrtomium falcatum (Dryopteridaceae) from Dokdo Island Based on Chloroplast Genome Sequencing
by Gurusamy Raman, Kyoung Su Choi and SeonJoo Park
Genes 2016, 7(12), 115; https://doi.org/10.3390/genes7120115 - 02 Dec 2016
Cited by 24 | Viewed by 6698
Abstract
Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum [...] Read more.
Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum, and compared it with those of closely related species. The genes trnV-GAC and trnV-GAU were found to be present within the cp genome of C. falcatum, whereas trnP-GGG and rpl21 were lacking. Moreover, cp genomes of Cyrtomium devexiscapulae and Adiantum capillus-veneris lack trnP-GGG and rpl21, suggesting these are not conserved among angiosperm cp genomes. The deletion of trnR-UCG, trnR-CCG, and trnSeC in the cp genomes of C. falcatum and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The C. falcatum cp genome also encoded ndhF and rps7, with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the trnD-GUC region and an approximate 3 kb inversion of the trnG-trnT region. Phylogenetic analyses showed that Equisetum was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that C. falcatum diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island. Full article
(This article belongs to the Section Molecular Genetics and Genomics)
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Article
Transcriptome Analysis of the Tadpole Shrimp (Triops longicaudatus) by Illumina Paired-End Sequencing: Assembly, Annotation, and Marker Discovery
by Jiyeon Seong, Se Won Kang, Bharat Bhusan Patnaik, So Young Park, Hee Ju Hwang, Jong Min Chung, Dae Kwon Song, Mi Young Noh, Seung-Hwan Park, Gwang Joo Jeon, Hong Sik Kong, Soonok Kim, Ui Wook Hwang, Hong Seog Park, Yeon Soo Han and Yong Seok Lee
Genes 2016, 7(12), 114; https://doi.org/10.3390/genes7120114 - 02 Dec 2016
Cited by 15 | Viewed by 7852
Abstract
The tadpole shrimp (Triops longicaudatus) is an aquatic crustacean that helps control pest populations. It inhabits freshwater ponds and pools and has been described as a living fossil. T. longicaudatus was officially declared an endangered species South Korea in 2005; however, through [...] Read more.
The tadpole shrimp (Triops longicaudatus) is an aquatic crustacean that helps control pest populations. It inhabits freshwater ponds and pools and has been described as a living fossil. T. longicaudatus was officially declared an endangered species South Korea in 2005; however, through subsequent protection and conservation management, it was removed from the endangered species list in 2012. The limited number of available genetic resources on T. longicaudatus makes it difficult to obtain valuable genetic information for marker-aided selection programs. In this study, whole-transcriptome sequencing of T. longicaudatus generated 39.74 GB of clean data and a total of 269,822 contigs using the Illumina HiSeq 2500 platform. After clustering, a total of 208,813 unigenes with an N50 length of 1089 bp were generated. A total of 95,105 unigenes were successfully annotated against Protostome (PANM), Unigene, Eukaryotic Orthologous Groups (KOG), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases using BLASTX with a cut-off of 1E−5. A total of 57,731 unigenes were assigned to GO terms, and 7247 unigenes were mapped to 129 KEGG pathways. Furthermore, 1595 simple sequence repeats (SSRs) were detected from the unigenes with 1387 potential SSR markers. This is the first report of high-throughput transcriptome analysis of T. longicaudatus, and it provides valuable insights for genetic research and molecular-assisted breeding of this important species. Full article
(This article belongs to the Section Molecular Genetics and Genomics)
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Review
H-NS, Its Family Members and Their Regulation of Virulence Genes in Shigella Species
by Michael A. Picker and Helen J. Wing
Genes 2016, 7(12), 112; https://doi.org/10.3390/genes7120112 - 01 Dec 2016
Cited by 22 | Viewed by 6623
Abstract
The histone-like nucleoid structuring protein (H-NS) has played a key role in shaping the evolution of Shigella spp., and provides the backdrop to the regulatory cascade that controls virulence by silencing many genes found on the large virulence plasmid. H-NS and its paralogue [...] Read more.
The histone-like nucleoid structuring protein (H-NS) has played a key role in shaping the evolution of Shigella spp., and provides the backdrop to the regulatory cascade that controls virulence by silencing many genes found on the large virulence plasmid. H-NS and its paralogue StpA are present in all four Shigella spp., but a second H-NS paralogue, Sfh, is found in the Shigella flexneri type strain 2457T, which is routinely used in studies of Shigella pathogenesis. While StpA and Sfh have been proposed to serve as “molecular backups” for H-NS, the apparent redundancy of these proteins is questioned by in vitro studies and work done in Escherichia coli. In this review, we describe the current understanding of the regulatory activities of the H-NS family members, the challenges associated with studying these proteins and their role in the regulation of virulence genes in Shigella. Full article
(This article belongs to the Special Issue Virulence Gene Regulation in Bacteria)
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Article
Genome-Wide Survey Reveals Transcriptional Differences Underlying the Contrasting Trichome Phenotypes of Two Sister Desert Poplars
by Jianchao Ma, Xiaodong He, Xiaotao Bai, Zhimin Niu, Bingbing Duan, Ningning Chen, Xuemin Shao and Dongshi Wan
Genes 2016, 7(12), 111; https://doi.org/10.3390/genes7120111 - 01 Dec 2016
Cited by 7 | Viewed by 4296
Abstract
Trichomes, which are widely used as an important diagnostic characteristic in plant species delimitation, play important roles in plant defense and adaptation to adverse environments. In this study, we used two sister poplar species, Populus pruinosa and Populus euphratica—which have, respectively, dense [...] Read more.
Trichomes, which are widely used as an important diagnostic characteristic in plant species delimitation, play important roles in plant defense and adaptation to adverse environments. In this study, we used two sister poplar species, Populus pruinosa and Populus euphratica—which have, respectively, dense and sparse trichomes—to examine the genetic differences associated with these contrasting phenotypes. The results showed that 42 and 45 genes could be identified as candidate genes related to trichomes in P. pruinosa and P. euphratica, respectively; most of these genes possessed high degrees of diversification in their coding sequences, but they were similar in intron/exon structure in the two species. We also found that most of the candidate trichome genes were expressed at higher levels in P. pruinosa, which has dense trichomes, than in P. euphratica, where there are few trichomes. Based on analyses of transcriptional profiles, a total of 195 genes, including many transcription factors, were found to show distinct differences in expression. The results of gene function annotation suggested that the genes identified as having contrasting levels of expression level are mainly associated with trichome elongation, ATPase activity, and hormone transduction. Changes in the expression of these and other related genes with high sequence diversification may have contributed to the contrast in the pattern of trichome phenotypes between the two species. Full article
(This article belongs to the Section Population and Evolutionary Genetics and Genomics)
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Article
Divergent Expression Patterns in Two Vernicia Species Revealed the Potential Role of the Hub Gene VmAP2/ERF036 in Resistance to Fusarium oxysporum in Vernicia montana
by Qiyan Zhang, Ming Gao, Liwen Wu, Yangdong Wang and Yicun Chen
Genes 2016, 7(12), 109; https://doi.org/10.3390/genes7120109 - 01 Dec 2016
Cited by 8 | Viewed by 5027
Abstract
Tung oil tree (Vernicia fordii) is a promising industrial oil crop; however, this tree is highly susceptible to Fusarium wilt disease. Conversely, Vernicia montana is resistant to the pathogen. The APETALA2/ethylene-responsive element binding factor (AP2/ERF) transcription factor superfamily has been reported [...] Read more.
Tung oil tree (Vernicia fordii) is a promising industrial oil crop; however, this tree is highly susceptible to Fusarium wilt disease. Conversely, Vernicia montana is resistant to the pathogen. The APETALA2/ethylene-responsive element binding factor (AP2/ERF) transcription factor superfamily has been reported to play a significant role in resistance to Fusarium oxysporum. In this study, comprehensive analysis identified 75 and 81 putative Vf/VmAP2/ERF transcription factor-encoding genes in V. fordii and V. montana, respectively, which were divided into AP2, ERF, related to ABI3 and VP1 (RAV) and Soloist families. After F. oxysporum infection, a majority of AP2/ERF superfamily genes showed strong patterns of repression in both V. fordii and V. montana. We then identified 53 pairs of one-to-one orthologs in V. fordii and V. montana, with most pairs of orthologous genes exhibiting similar expression in response to the pathogen. Further investigation of Vf/VmAP2/ERF gene expression in plant tissues indicated that the pairs of genes with different expression patterns in response to F. oxysporum tended to exhibit different tissue profiles in the two species. In addition, VmAP2/ERF036, showing the strongest interactions with 666 genes, was identified as a core hub gene mediating resistance. Moreover, qRT-PCR results indicated VmAP2/ERF036 showed repressed expression while its orthologous gene VfAP2/ERF036 had the opposite expression pattern during pathogen infection. Overall, comparative analysis of the Vf/VmAP2/ERF superfamily and indication of a potential hub resistance gene in resistant and susceptible Vernicia species provides valuable information for understanding the molecular basis and selection of essential functional genes for V. fordii genetic engineering to control Fusarium wilt disease. Full article
(This article belongs to the Section Molecular Genetics and Genomics)
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Review
Development of Genetic Testing for Fragile X Syndrome and Associated Disorders, and Estimates of the Prevalence of FMR1 Expansion Mutations
by James N. Macpherson and Anna Murray
Genes 2016, 7(12), 110; https://doi.org/10.3390/genes7120110 - 30 Nov 2016
Cited by 10 | Viewed by 7336
Abstract
The identification of a trinucleotide (CGG) expansion as the chief mechanism of mutation in Fragile X syndrome in 1991 heralded a new chapter in molecular diagnostic genetics and generated a new perspective on mutational mechanisms in human genetic disease, which rapidly became a [...] Read more.
The identification of a trinucleotide (CGG) expansion as the chief mechanism of mutation in Fragile X syndrome in 1991 heralded a new chapter in molecular diagnostic genetics and generated a new perspective on mutational mechanisms in human genetic disease, which rapidly became a central paradigm (“dynamic mutation”) as more and more of the common hereditary neurodevelopmental disorders were ascribed to this novel class of mutation. The progressive expansion of a CGG repeat in the FMR1 gene from “premutation” to “full mutation” provided an explanation for the “Sherman paradox,” just as similar expansion mechanisms in other genes explained the phenomenon of “anticipation” in their pathogenesis. Later, FMR1 premutations were unexpectedly found associated with two other distinct phenotypes: primary ovarian insufficiency and tremor-ataxia syndrome. This review will provide a historical perspective on procedures for testing and reporting of Fragile X syndrome and associated disorders, and the population genetics of FMR1 expansions, including estimates of prevalence and the influence of AGG interspersions on the rate and probability of expansion. Full article
(This article belongs to the Special Issue Fragile X Syndrome)
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Article
Cucumber Metallothionein-Like 2 (CsMTL2) Exhibits Metal-Binding Properties
by Yu Pan, Yanglu Pan, Junpeng Zhai, Yan Xiong, Jinhua Li, Xiaobing Du, Chenggang Su and Xingguo Zhang
Genes 2016, 7(12), 106; https://doi.org/10.3390/genes7120106 - 30 Nov 2016
Cited by 16 | Viewed by 4808
Abstract
We identified a novel member of the metallothionein (MT) family, Cucumis sativus metallothionein-like 2 (CsMTL2), by screening a young cucumber fruit complementary DNA (cDNA) library. The CsMTL2 encodes a putative 77-amino acid Class II MT protein that contains two cysteine (Cys)-rich domains separated [...] Read more.
We identified a novel member of the metallothionein (MT) family, Cucumis sativus metallothionein-like 2 (CsMTL2), by screening a young cucumber fruit complementary DNA (cDNA) library. The CsMTL2 encodes a putative 77-amino acid Class II MT protein that contains two cysteine (Cys)-rich domains separated by a Cys-free spacer region. We found that CsMTL2 expression was regulated by metal stress and was specifically induced by Cd2+ treatment. We investigated the metal-binding characteristics of CsMTL2 and its possible role in the homeostasis and/or detoxification of metals by heterologous overexpression in Escherichia coli cells. Furthermore, we produced a deletion mutant form of the protein, CsMTL2m, that contained the two Cys-rich clusters but lacked the spacer region, in E. coli. We compared the metal-binding properties of CsMTL2 with those of CsMTL2m, the β domain of human metallothionein-like protein 1 (HsMTXb), and phytochelatin-like (PCL) heterologously expressed in E. coli using metal-binding assays. We found that E. coli cells expressing CsMTL2 accumulated the highest levels of Zn2+ and Cd2+ of the four transformed cell types, with levels being significantly higher than those of control cells containing empty vector. E. coli cells expressing CsMTL2 had a higher tolerance for cadmium than for zinc ions. These findings show that CsMTL2 improves metal tolerance when heterologously expressed in E. coli. Future studies should examine whether CsMTL2 improves metal tolerance in planta. Full article
(This article belongs to the Section Molecular Genetics and Genomics)
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Case Report
Novel PIGT Variant in Two Brothers: Expansion of the Multiple Congenital Anomalies-Hypotonia Seizures Syndrome 3 Phenotype
by Nadia Skauli, Sean Wallace, Samuel C. C. Chiang, Tuva Barøy, Asbjørn Holmgren, Asbjørg Stray-Pedersen, Yenan T. Bryceson, Petter Strømme, Eirik Frengen and Doriana Misceo
Genes 2016, 7(12), 108; https://doi.org/10.3390/genes7120108 - 29 Nov 2016
Cited by 20 | Viewed by 7531
Abstract
Biallelic PIGT variants were previously reported in seven patients from three families with Multiple Congenital Anomalies-Hypotonia Seizures Syndrome 3 (MCAHS3), characterized by epileptic encephalopathy, hypotonia, global developmental delay/intellectual disability, cerebral and cerebellar atrophy, craniofacial dysmorphisms, and skeletal, ophthalmological, cardiac, and genitourinary abnormalities. We [...] Read more.
Biallelic PIGT variants were previously reported in seven patients from three families with Multiple Congenital Anomalies-Hypotonia Seizures Syndrome 3 (MCAHS3), characterized by epileptic encephalopathy, hypotonia, global developmental delay/intellectual disability, cerebral and cerebellar atrophy, craniofacial dysmorphisms, and skeletal, ophthalmological, cardiac, and genitourinary abnormalities. We report a novel homozygous PIGT missense variant c.1079G>T (p.Gly360Val) in two brothers with several of the typical features of MCAHS3, but in addition, pyramidal tract neurological signs. Notably, they are the first patients with MCAHS3 without skeletal, cardiac, or genitourinary anomalies. PIGT encodes a crucial subunit of the glycosylphosphatidylinositol (GPI) transamidase complex, which catalyzes the attachment of proteins to GPI-anchors, attaching the proteins to the cell membrane. In vitro studies in cells from the two brothers showed reduced levels of GPI-anchors and GPI-anchored proteins on the cell surface, supporting the pathogenicity of the novel PIGT variant. Full article
(This article belongs to the Section Human Genomics and Genetic Diseases)
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Article
In Silico Characterization of miRNA and Long Non-Coding RNA Interplay in Multiple Myeloma
by Domenica Ronchetti, Martina Manzoni, Katia Todoerti, Antonino Neri and Luca Agnelli
Genes 2016, 7(12), 107; https://doi.org/10.3390/genes7120107 - 29 Nov 2016
Cited by 14 | Viewed by 6152
Abstract
The identification of deregulated microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in multiple myeloma (MM) has progressively added a further level of complexity to MM biology. In addition, the cross-regulation between lncRNAs and miRNAs has begun to emerge, and theoretical and experimental studies [...] Read more.
The identification of deregulated microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in multiple myeloma (MM) has progressively added a further level of complexity to MM biology. In addition, the cross-regulation between lncRNAs and miRNAs has begun to emerge, and theoretical and experimental studies have demonstrated the competing endogenous RNA (ceRNA) activity of lncRNAs as natural miRNA decoys in pathophysiological conditions, including cancer. Currently, information concerning lncRNA and miRNA interplay in MM is virtually absent. Herein, we investigated in silico the lncRNA and miRNA relationship in a representative datasets encompassing 95 MM and 30 plasma cell leukemia patients at diagnosis and in four normal controls, whose expression profiles were generated by a custom annotation pipeline to detect specific lncRNAs. We applied target prediction analysis based on miRanda and RNA22 algorithms to 235 lncRNAs and 459 miRNAs selected with a potential pivotal role in the pathology of MM. Among pairs that showed a significant correlation between lncRNA and miRNA expression levels, we identified 11 lncRNA–miRNA relationships suggestive of a novel ceRNA network with relevance in MM. Full article
(This article belongs to the Special Issue microRNAs and Other Non-Coding RNAs in Human Diseases)
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Article
Postnatal Gene Therapy Improves Spatial Learning Despite the Presence of Neuronal Ectopia in a Model of Neuronal Migration Disorder
by Huaiyu Hu, Yu Liu, Kevin Bampoe, Yonglin He and Miao Yu
Genes 2016, 7(12), 105; https://doi.org/10.3390/genes7120105 - 29 Nov 2016
Cited by 5 | Viewed by 5174
Abstract
Patients with type II lissencephaly, a neuronal migration disorder with ectopic neurons, suffer from severe mental retardation, including learning deficits. There is no effective therapy to prevent or correct the formation of neuronal ectopia, which is presumed to cause cognitive deficits. We hypothesized [...] Read more.
Patients with type II lissencephaly, a neuronal migration disorder with ectopic neurons, suffer from severe mental retardation, including learning deficits. There is no effective therapy to prevent or correct the formation of neuronal ectopia, which is presumed to cause cognitive deficits. We hypothesized that learning deficits were not solely caused by neuronal ectopia and that postnatal gene therapy could improve learning without correcting the neuronal ectopia formed during fetal development. To test this hypothesis, we evaluated spatial learning of cerebral cortex-specific protein O-mannosyltransferase 2 (POMT2, an enzyme required for O-mannosyl glycosylation) knockout mice and compared to the knockout mice that were injected with an adeno-associated viral vector (AAV) encoding POMT2 into the postnatal brains with Barnes maze. The data showed that the knockout mice exhibited reduced glycosylation in the cerebral cortex, reduced dendritic spine density on CA1 neurons, and increased latency to the target hole in the Barnes maze, indicating learning deficits. Postnatal gene therapy restored functional glycosylation, rescued dendritic spine defects, and improved performance on the Barnes maze by the knockout mice even though neuronal ectopia was not corrected. These results indicate that postnatal gene therapy improves spatial learning despite the presence of neuronal ectopia. Full article
(This article belongs to the Section Human Genomics and Genetic Diseases)
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