Enriched Functional Categories Research Articles

Transcriptomic analysis of transgressive segregants revealed the central role of photosynthetic capacity and efficiency in biomass accumulation in sugarcane

Sugarcane is among the most efficient crops in converting solar energy into chemical energy. However, due to its complex genome structure and inheritance, the genetic and molecular basis of biomass yield in sugarcane is still largely unknown. We created an F2 segregating population by crossing S. officinarum and S. spontaneum and evaluated the biomass yield of the F2 individuals. The F2 individuals exhibited clear transgressive segregation in biomass yield. We sequenced transcriptomes of source and sink tissues from 12 selected extreme segregants to explore the molecular basis of high biomass yield for future breeding of high-yielding energy canes. Among the 103,664 assembled unigenes, 10,115 and 728 showed significant differential expression patterns between the two extreme segregating groups in the top visible dewlap leaf and the 9th culm internode, respectively. The most enriched functional categories were photosynthesis and fermentation in the high-biomass and the low-biomass groups, respectively. Our results revealed that high-biomass yield was mainly determined by assimilation of carbon in source tissues. The high-level expression of fermentative genes in the low-biomass group was likely induced by their low-energy status. Group-specific expression alleles which can be applied in the development of new high-yielding energy cane varieties via molecular breeding were identified.

Integrated Analysis of the Transcriptome and Metabolome of Corynebacterium glutamicum during Penicillin-Induced Glutamic Acid Production.

Corynebacterium glutamicum is known for its ability to produce glutamic acid and has been utilized for the fermentative production of various amino acids. Glutamic acid production in C. glutamicum is induced by penicillin. In this study, the transcriptome and metabolome of C. glutamicum is analyzed to understand the mechanism of penicillin-induced glutamic acid production. Transcriptomic analysis with DNA microarray revealed that expression of some glycolysis- and TCA cycle-related genes, which include those encoding the enzymes involved in conversion of glucose to 2-oxoglutaric acid, is upregulated after penicillin addition. Meanwhile, expression of some TCA cycle-related genes, encoding the enzymes for conversion of 2-oxoglutaric acid to oxaloacetic acid, and the anaplerotic reactions decreased. In addition, expression of NCgl1221 and odhI, encoding proteins involved in glutamic acid excretion and inhibition of the 2-oxoglutarate dehydrogenase, respectively, is upregulated. Functional category enrichment analysis of genes upregulated and downregulated after penicillin addition revealed that genes for signal transduction systems are enriched among upregulated genes, whereas those for energy production and carbohydrate and amino acid metabolisms are enriched among the downregulated genes. As for the metabolomic analysis using capillary electrophoresis time-of-flight mass spectrometry, the intracellular content of most metabolites of the glycolysis and the TCA cycle decreased dramatically after penicillin addition. Overall, these results indicate that the cellular metabolism and glutamic acid excretion are mainly optimized at the transcription level during penicillin-induced glutamic acid production by C. glutamicum.

Genetic profiling and surface proteome analysis of human atrial stromal cells and rat ventricular epicardium-derived cells reveals novel insights into their cardiogenic potential

Epicardium-derived cells (EPDC) and atrial stromal cells (ASC) display cardio-regenerative potential, but the molecular details are still unexplored. Signals which induce activation, migration and differentiation of these cells are largely unknown. Here we have isolated rat ventricular EPDC and rat/human ASC and performed genetic and proteomic profiling. EPDC and ASC expressed epicardial/mesenchymal markers (WT-1, Tbx18, CD73, CD90, CD44, CD105), cardiac markers (Gata4, Tbx5, troponin T) and also contained phosphocreatine. We used cell surface biotinylation to isolate plasma membrane proteins of rEPDC and hASC, Nano-liquid chromatography with subsequent mass spectrometry and bioinformatics analysis identified 396 rat and 239 human plasma membrane proteins with 149 overlapping proteins. Functional GO-term analysis revealed several significantly enriched categories related to extracellular matrix (ECM), cell migration/differentiation, immunology or angiogenesis. We identified receptors for ephrin and growth factors (IGF, PDGF, EGF, anthrax toxin) known to be involved in cardiac repair and regeneration. Functional category enrichment identified clusters around integrins, PI3K/Akt-signaling and various cardiomyopathies. Our study indicates that EPDC and ASC have a similar molecular phenotype related to cardiac healing/regeneration. The cell surface proteome repository will help to further unravel the molecular details of their cardio-regenerative potential and their role in cardiac diseases.

A Community Challenge for Inferring Genetic Predictors of Gene Essentialities through Analysis of a Functional Screen of Cancer Cell Lines.

We report the results of a DREAM challenge designed to predict relative genetic essentialities based on a novel dataset testing 98,000 shRNAs against 149 molecularly characterized cancer cell lines. We analyzed the results of over 3,000 submissions over a period of 4months. We found that algorithms combining essentiality data across multiple genes demonstrated increased accuracy; gene expression was the most informative molecular data type; the identity of the gene being predicted was far more important than the modeling strategy; well-predicted genes and selected molecular features showed enrichment in functional categories; and frequently selected expression features correlated with survival in primary tumors. This study establishes benchmarks for geneessentiality prediction, presents a community resource for future comparison with this benchmark, and provides insights into factors influencing the ability to predict gene essentiality from functional genetic screens. This study also demonstrates the value of releasing pre-publication data publicly to engage the community in an open research collaboration.

Transcriptome dynamics of Camellia sinensis in response to continuous salinity and drought stress

Camellia sinensis is an important economic crop worldwide since this plant is used to make one of the most popular non-alcoholic beverages, tea. Salinity together with drought pose a serious threat to the production and qualities of C. sinensis. However, the transcriptome dynamics occurring in response to drought stress and salt stress in tea plants are poorly understood at the molecular level. We reported the first large-coverage transcriptome datasets for C. sinensis under drought and salt stress using next-generation sequencing technology. Using a high-throughput Illumina sequencing platform, approximately 398.95 million high-quality paired-end reads were generated from young leaves of C. sinensis subjected to drought stress and salt stress, and these reads were used for de novo assembly. The transcripts with further processing and filtering yielded a set of 64,905 coding DNA sequences (CDSs) with an average length of 710 bp and an N50 of 933 bp. In total, 3936 and 3715 differentially expressed genes (DEGs) were identified from all analyzed time points of drought stress and salt stress, respectively. Identified in drought and salt stress were 2131 overlapping DEGs, and these are involved in galactosyltransferase activity, tetrapyrrole binding, and hydrolase activity, indicating that C. sinensis has a similar molecular response to these two stresses. We clustered the above DEGs from both sets into four clusters according to their expression dynamics, with the genes in each cluster showing enrichment for particular functional categories. We also found that under salt stress, most DEGs showed down-regulation at early time points and their expression levels were elevated after 48 h, whereas under drought stress most DEGs were down-regulated in all time points. The DEGs relative to pathways of osmotic product such as proline, sugar, and GABA were identified in C. sinensis. Noteworthy, among the identified DEGs are genes involved in the biosynthetic pathways of polyphenol and caffeine, providing evidence at the molecular level that salt and drought affect tea qualities. In addition, we analyzed the differential expression of transcription factors and revealed a large amount of crosstalk between the metabolic pathways of drought and salt stress. All findings suggest that gene expression exhibits rapid and coordinated changes during C. sinensis adaptations to drought stress and salt stress, and common themes in the response to both stresses were identified.

Experience-dependent epigenomic reorganization in the hippocampus.

Using a hippocampus-dependent contextual threat learning and memory task, we report widespread, coordinated DNA methylation changes in CA1 hippocampus of Sprague-Dawley rats specific to threat learning at genes involved in synaptic transmission. Experience-dependent alternations in gene expression and DNA methylation were observed as early as 1 h following memory acquisition and became more pronounced after 24 h. Gene ontology analysis revealed significant enrichment of functional categories related to synaptic transmission in genes that were hypomethylated at 24 h following threat learning. Integration of these data sets with previously characterized epigenetic and transcriptional changes in brain disease states suggested significant overlap between genes regulated by memory formation and genes altered in memory-related neurological and neuropsychiatric diseases. These findings provide a comprehensive resource to aid in the identification of memory-relevant therapeutic targets. Our results shed new light on the gene expression and DNA methylation changes involved in memory formation, confirming that these processes are dynamic and experience-dependent. Finally, this work provides a roadmap for future studies to identify linkage of memory-associated genes to altered disease states.

Transcriptome analysis of smut fungi reveals widespread intergenic transcription and conserved antisense transcript expression

BackgroundBiotrophic fungal plant pathogens cause billions of dollars in losses to North American crops annually. The model for functional investigation of these fungi is Ustilago maydis. Its 20.5 Mb annotated genome sequence has been an excellent resource for investigating biotrophic plant pathogenesis. Expressed-sequence tag libraries and microarray hybridizations have provided insight regarding the type of transcripts produced by U. maydis but these analyses were not comprehensive and there were insufficient data for transcriptome comparison to other smut fungi. To improve transcriptome annotation and enable comparative analyses, comprehensive strand-specific RNA-seq was performed on cell-types of three related smut species: U. maydis (common smut of corn), Ustilago hordei (covered smut of barley), and Sporisorium reilianum (head smut of corn).ResultsIn total, >1 billion paired-end sequence reads were obtained from haploid cell, dikaryon and teliospore RNA of U. maydis, haploid cell RNA of U. hordei, and haploid and dikaryon cell RNA of S. reilianum. The sequences were assembled into transfrags using Trinity, and updated gene models were created using PASA and categorized with Cufflinks Cuffcompare. Representative genes that were predicted for the first time with these RNA-seq analyses and genes with novel annotation features were independently assessed by reverse transcriptase PCR. The analyses indicate hundreds more predicted proteins, relative to the previous genome annotation, could be produced by U. maydis from altered transcript forms, and that the number of non-coding RNAs produced, including transcribed intergenic sequences and natural antisense transcripts, approximately equals the number of mRNAs. This high representation of non-coding RNAs appears to be a conserved feature of the smut fungi regardless of whether they have RNA interference machinery. Approximately 50% of the identified NATs were conserved among the smut fungi.ConclusionsOverall, these analyses revealed: 1) smut genomes encode a number of transcriptional units that is twice the number of annotated protein-coding genes, 2) a small number of intergenic transcripts may encode proteins with characteristics of fungal effectors, 3) the vast majority of intergenic and antisense transcripts do not contain ORFs, 4) a large proportion of the identified antisense transcripts were detected at orthologous loci among the smut fungi, and 5) there is an enrichment of functional categories among orthologous loci that suggests antisense RNAs could have a genome-wide, non-RNAi-mediated, influence on gene expression in smut fungi.

A comprehensive regional analysis of genome-wide expression profiles for major depressive disorder

BackgroundMajor depressive disorder (MDD) is a global health challenge. In recent years, a large number of genome-wide expression studies (GWES) have been carried out to identify the transcriptomic profiles for MDD. The objective of this work was to carry out a comprehensive meta-analysis of available GWES for MDD. MethodsGWES for MDD with available raw data were searched in NCBI GEO, Array Express and Stanley databases. Raw GWES data were preprocessed and normalized and meta-analytical procedures were carried out with the Network Analyst program. 743 samples from 24 primary studies were included in our meta-analyses for blood (Blo), amygdala (Amy), cerebellum (Cer), anterior cingulate cortex (ACC) and prefrontal cortex (PFC) regions. A functional enrichment analysis was carried out. ResultsWe identified 35, 793, 231, 668 and 252 differentially expressed (DE) genes for Blo, Amy, Cer, ACC and PFC regions. A region-dependent significant enrichment for several functional categories, such as gene ontologies, signaling pathways and topographic parameters, was identified. There was convergence with other available genome-wide studies, such as GWAS, DNA methylation analyses and miRNA expression studies. LimitationsRaw data were not available for several primary studies that have been published previously. ConclusionsThis is the largest meta-analysis for GWES in MDD. The examination of convergence of genome-wide evidence and of the functional enrichment analysis provides a global overview of potential neural signaling mechanisms dysregulated in MDD. Our comprehensive analysis of several brain regions identified lists of DE genes for MDD that are interesting candidates for further studies.

Rapid Genetic Adaptation during the First Four Months of Survival under Resource Exhaustion.

Many bacteria, including the model bacterium Escherichia coli can survive for years within spent media, following resource exhaustion. We carried out evolutionary experiments, followed by whole genome sequencing of hundreds of evolved clones to study the dynamics by which E. coli adapts during the first 4 months of survival under resource exhaustion. Our results reveal that bacteria evolving under resource exhaustion are subject to intense selection, manifesting in rapid mutation accumulation, enrichment in functional mutation categories and extremely convergent adaptation. In the most striking example of convergent adaptation, we found that across five independent populations adaptation to conditions of resource exhaustion occurs through mutations to the three same specific positions of the RNA polymerase core enzyme. Mutations to these three sites are strongly antagonistically pleiotropic, in that they sharply reduce exponential growth rates in fresh media. Such antagonistically pleiotropic mutations, combined with the accumulation of additional mutations, severely reduce the ability of bacteria surviving under resource exhaustion to grow exponentially in fresh media. We further demonstrate that the three positions at which these resource exhaustion mutations occur are conserved for the ancestral E. coli allele, across bacterial phyla, with the exception of nonculturable bacteria that carry the resource exhaustion allele at one of these positions, at very high frequencies. Finally, our results demonstrate that adaptation to resource exhaustion is not limited by mutational input and that bacteria are able to rapidly adapt under resource exhaustion in a temporally precise manner through allele frequency fluctuations.

Functional Architectures of Local and Distal Regulation of Gene Expression in Multiple Human Tissues

Genetic variants that modulate gene expression levels play an important role in the etiology of human diseases and complex traits. Although large-scale eQTL mapping studies routinely identify many local eQTLs, the molecular mechanisms by which genetic variants regulate expression remain unclear, particularly for distal eQTLs, which these studies are not well powered to detect. Here, we leveraged all variants (not just those that pass stringent significance thresholds) to analyze the functional architecture of local and distal regulation of gene expression in 15 human tissues by employing an extension of stratified LD-score regression that produces robust results in simulations. The top enriched functional categories in local regulation of peripheral-blood gene expression included coding regions (11.41×), conserved regions (4.67×), and four histone marks (p < 5× 10-5 for all enrichments); local enrichments were similar across the 15 tissues. We also observed substantial enrichments for distal regulation of peripheral-blood gene expression: coding regions (4.47×), conserved regions (4.51×), and two histone marks (p < 3× 10-7 for all enrichments). Analyses of the genetic correlation of gene expression across tissues confirmed that local regulation of gene expression is largely shared across tissues but that distal regulation is highly tissue specific. Our results elucidate the functional components of the genetic architecture of local and distal regulation of gene expression.

Genetic Mechanisms Leading to Sex Differences Across Common Diseases and Anthropometric Traits.

Common diseases often show sex differences in prevalence, onset, symptomology, treatment, or prognosis. Although studies have been performed to evaluate sex differences at specific SNP associations, this work aims to comprehensively survey a number of complex heritable diseases and anthropometric traits. Potential genetically encoded sex differences we investigated include differential genetic liability thresholds or distributions, gene-sex interaction at autosomal loci, major contribution of the X-chromosome, or gene-environment interactions reflected in genes responsive to androgens or estrogens. Finally, we tested the overlap between sex-differential association with anthropometric traits and disease risk. We utilized complementary approaches of assessing GWAS association enrichment and SNP-based heritability estimation to explore explicit sex differences, as well as enrichment in sex-implicated functional categories. We do not find consistent increased genetic load in the lower-prevalence sex, or a disproportionate role for the X-chromosome in disease risk, despite sex-heterogeneity on the X for several traits. We find that all anthropometric traits show less than complete correlation between the genetic contribution to males and females, and find a convincing example of autosome-wide genome-sex interaction in multiple sclerosis (P=1×10-9). We also find some evidence for hormone-responsive gene enrichment, and striking evidence of the contribution of sex-differential anthropometric associations to common disease risk, implying that general mechanisms of sexual dimorphism determining secondary sex characteristics have shared effects on disease risk.

Population Structure Analysis of Bull Genomes of European and Western Ancestry

Since domestication, population bottlenecks, breed formation, and selective breeding have radically shaped the genealogy and genetics of Bos taurus. In turn, characterization of population structure among diverse bull (males of Bos taurus) genomes enables detailed assessment of genetic resources and origins. By analyzing 432 unrelated bull genomes from 13 breeds and 16 countries, we demonstrate genetic diversity and structural complexity among the European/Western cattle population. Importantly, we relaxed a strong assumption of discrete or admixed population, by adapting latent variable models for individual-specific allele frequencies that directly capture a wide range of complex structure from genome-wide genotypes. As measured by magnitude of differentiation, selection pressure on SNPs within genes is substantially greater than that on intergenic regions. Additionally, broad regions of chromosome 6 harboring largest genetic differentiation suggest positive selection underlying population structure. We carried out gene set analysis using SNP annotations to identify enriched functional categories such as energy-related processes and multiple development stages. Our population structure analysis of bull genomes can support genetic management strategies that capture structural complexity and promote sustainable genetic breadth.

M58 - Cross-Tissue EQTL Enrichment of Associations In Schizophrenia

Background In the era of Big Data, genome-wide association studies (GWASs) have been the main instrument to better our understanding of the genetics behind human traits. The schizophrenia GWAS by the psychiatric genomics consortium (PGC) identified many loci plausibly involved in the etiology of the disorder [Ripke et al., 2014]. However, the picture appears to be far from complete [Lichtenstein, 2009; Polderman, 2015; Gejman, 2010; Lee, 2012]. Judging by the number of non-coding variants identified by GWASs of schizophrenia and other complex traits, many causal variants are likely to affect the regulation of the genes involved rather than severely disrupt their function. Expression quantitative trait loci (eQTLs) are genomic loci that contribute to variation in levels of mRNA. It is known [Bacanu, 2014] that many eQTLs are associated with schizophrenia, as well as other phenotypes [Nicolae, 2010]. Methods Given known pleiotropy between schizophrenia and other traits, we looked for association enrichment of eQTLs in tissues not obviously relevant to psychiatric disorders (blood, adipose, LCL, and skin [Buil, 2015]). In order to consolidate any evidence of tissue-specificity, we further looked for differential enrichment in different ENCODE functional annotation categories. We used summary p-value statistics from schizophrenia as well as body mass index, Crohn's disease, height, systolic blood pressure and type II diabetes GWASs. We matched the eQTLs to SNP sets with similar minor allele frequencies (MAF) and distances from their respective transcription start sites (TSS), and no evidence of association with expression levels of any genes. We further subdivided eQTLs into proximal and distal eQTLs, according to their position relative to the TSS or to their affiliation to promoters, and we annotated them according to their ENCODE designation. We visualized the enrichment in fold enrichment plots, screened it using Fisher tests and assessed its extent by regressing the squared association z-score against SNP affiliations and LD-score. Results Significant enrichment was seen in adipose (beta=0.24, p=2.2E-06), LCL (beta=0.27, p=4.0E-08) and skin (beta=0.23, p=2.7E-06) tissues. The enrichment was as widespread as that observed in another highly polygenic trait such as height, and more widespread than in traits such as body mass index (adipose and skin) or blood pressure (adipose). The schizophrenia association extent does not appear to depend on the eQTLs' distance from the TSS nor from their explicit affiliation to specific functional elements, as defined by ENCODE, suggesting that risk alleles for schizophrenia could frequently act in many different tissue contexts. Discussion Our results are in line with the notion that schizophrenia is a disorder involving many tissues and known pleiotropy with cardiovascular and immune diseases back our findings. The statistical power of the underlying GWAS does play a role in the detection of association enrichment of the sort we sought. Polygenicity, however, is also a major factor, as exemplified by the results for height, body mass index and blood pressure. In summary, we find that looking for functional correlates of schizophrenia risk loci in non-obvious tissues is productive, and this could be because of either pleiotropy or increased effectiveness of variants that work in many different environmental contexts. This suggests the utility of large, single tissue eQTL experiments in the study of schizophrenia in addition to smaller, multiple tissue approaches.

Cross-talk between lipid and protein carbonylation in a dynamic cardiomyocyte model of mild nitroxidative stress

Reactive oxygen and nitrogen species (ROS/RNS) play an important role in the regulation of cardiac function. Increase in ROS/RNS concentration results in lipid and protein oxidation and is often associated with onset and/or progression of many cardiovascular disorders. However, interplay between lipid and protein modifications has not been simultaneously studied in detail so far. Biomolecule carbonylation is one of the most common biomarkers of oxidative stress. Using a dynamic model of nitroxidative stress we demonstrated rapid changes in biomolecule carbonylation in rat cardiomyocytes. Levels of carbonylated species increased as early as 15min upon treatment with the peroxynitrite donor, 3-morpholinosydnonimine (SIN-1), and decreased to values close to control after 16h. Total (lipids+proteins) vs. protein-specific carbonylation showed different dynamics, with a significant increase in protein-bound carbonyls at later time points. Treatment with SIN-1 in combination with inhibitors of proteasomal and autophagy/lysosomal degradation pathways allowed confirmation of a significant role of the proteasome in the degradation of carbonylated proteins, whereas lipid carbonylation increased in the presence of autophagy/lysosomal inhibitors. Electrophilic aldehydes and ketones formed by lipid peroxidation were identified and relatively quantified using LC-MS/MS. Molecular identity of reactive species was used for data-driven analysis of their protein targets. Combination of different enrichment strategies with LC-MS/MS analysis allowed identification of more than 167 unique proteins with 332 sites modified by electrophilic lipid peroxidation products. Gene ontology analysis of modified proteins demonstrated enrichment of several functional categories including proteins involved in cytoskeleton, extracellular matrix, ion channels and their regulation. Using calcium mobilization assays, the effect of nitroxidative stress on the activity of several ion channels was further confirmed.

Transcriptome analysis of genes involved in anthocyanins biosynthesis and transport in berries of black and white spine grapes (Vitis davidii).

BackgroundThe color of berry skin is an important economic trait for grape and is essentially determined by the components and content of anthocyanins. The fruit color of Chinese wild grapes is generally black, and the profile of anthocyanins in Chinese wild grapes is significantly different from that of Vitis vinifera. However, V. davidii is the only species that possesses white berry varieties among Chinese wild grape species. Thus, we performed a transcriptomic analysis to compare the difference of transcriptional level in black and white V. davidii, in order to find some key genes that are related to anthocyanins accumulation in V. davidii.ResultsThe results of anthocyanins detection revealed that 3,5-O-diglucoside anthocyanins is the predominant anthocyanins in V. davidii. It showed obvious differences from V. vinifera in the profile of the composition of anthocyanins. The transcriptome sequencing by Illumina mRNA-Seq technology generated an average of 57 million 100-base pair clean reads from each sample. Differential gene expression analysis revealed thousands of differential expression genes (DEGs) in the pairwise comparison of different fruit developmental stages between and within black and white V. davidii. After the analysis of functional category enrichment and differential expression patterns of DEGs, 46 genes were selected as the candidate genes. Some genes have been reported as being related to anthocyanins accumulation, and some genes were newly found in our study as probably being related to anthocyanins accumulation. We inferred that 3AT (VIT_03s0017g00870) played an important role in anthocyanin acylation, GST4 (VIT_04s0079g00690) and AM2 (VIT_16s0050g00910) played important roles in anthocyanins transport in V. davidii. The expression of some selected DEGs was further confirmed by quantitative real-time PCR (qRT-PCR).ConclusionsThe present study investigated the transcriptomic profiles of berry skin from black and white spine grapes at three fruit developmental stages by Illumina mRNA-Seq technology. It revealed the variety specificity of anthocyanins accumulation in V. davidi at the transcriptional level. The data reported here will provide a valuable resource for understanding anthocyanins accumulation in grapes, especially in V. davidii.Electronic supplementary materialThe online version of this article (doi:10.1186/s41065-016-0021-1) contains supplementary material, which is available to authorized users.

Comparisons of chromosome Y-substituted mouse strains reveal that the male-specific chromosome modulates the effects of androgens on cardiac functions.

BackgroundThe C57BL/6J.YA/J mouse strain is a chromosome-substituted line where the original male-specific portion of chromosome Y (MSY) from C57BL/6J mice was substituted for that from A/J mice. In hearts from male C57BL/6J.YA/J and C57BL/6J mice, orchidectomy (ORX) affected in a strictly strain-specific fashion the expression a subset of genes showing enrichment for functional categories, including that of circadian rhythms and cardiac contractility. We further tested whether: (1) there were strain-specific differences in cardiac circadian rhythms; (2) strain-dependent differences in the effects of ORX on contractility genes translated into differences in cardiac functions; and (3) differential contractility responses occurred preferentially at times when circadian rhythms also showed strain-specific differences.MethodsIn hearts from the two above strains, we (1) profiled the expression levels of 15 circadian genes at 4-h intervals across a 24 h period; (2) tested the effects of either ORX or androgen replacement on expression of cardiac contractility genes, and that of ORX on myocardial functional reserve; and (3) verified whether the effects of MSY variants on cardiac contractility-related responses showed synchronicity with differences in circadian rhythms.ResultsAmong the 15 tested circadian genes, a subset of them were affected by strain (and thus the genetic origin of MSY), which interacted with the amplitude of their peak of maximal expression at 2:00 PM. At that same time-point, ORX decreased (and androgen supplementation increased) the expression of three contractility-related genes, and decreased myocardial relaxation reserve in C57BL/6J.YA/J, but not in C57BL/6J mice. These effects were not detected at 10:00 AM, i.e., at another time-point when circadian genes showed no strain-specific differences.ConclusionsThe results indicate that in mice, androgens have activational effects on cardiac circadian rhythms, contractile gene expression, and myocardial functional reserve. All effects occurred preferentially at the same time of the day, but varied as a function of the genetic origin of MSY. Androgens may therefore be necessary but not sufficient to impart male-specific characteristics to some particular cardiac functions, with genetic material from MSY being one other necessary factor to fully define their range of actions.Electronic supplementary materialThe online version of this article (doi:10.1186/s13293-016-0116-4) contains supplementary material, which is available to authorized users.

Functional and Genomic Features of Human Genes Mutated in Neuropsychiatric Disorders.

Background:In recent years, a large number of studies around the world have led to the identification of causal genes for hereditary types of common and rare neurological and psychiatric disorders.Objective: To explore the functional and genomic features of known human genes mutated in neuropsychiatric disorders.Methods: A systematic search was used to develop a comprehensive catalog of genes mutated in neuropsychiatric disorders (NPD). Functional enrichment and protein-protein interaction analyses were carried out. A false discovery rate approach was used for correction for multiple testing.Results: We found several functional categories that are enriched among NPD genes, such as gene ontologies, protein domains, tissue expression, signaling pathways and regulation by brain-expressed miRNAs and transcription factors. Sixty six of those NPD genes are known to be druggable. Several topographic parameters of protein-protein interaction networks and the degree of conservation between orthologous genes were identified as significant among NPD genes.Conclusion:These results represent one of the first analyses of enrichment of functional categories of genes known to harbor mutations for NPD. These findings could be useful for a future creation of computational tools for prioritization of novel candidate genes for NPD.

Comparative RNA-Seq profiling of berry development between table grape 'Kyoho' and its early-ripening mutant 'Fengzao'.

BackgroundEarly ripening is an important desirable attribute for fruit crops. ‘Kyoho’ is a popular table grape cultivar in many Asian countries. ‘Fengzao’ is a bud mutant of ‘Kyoho’ and ripens nearly 30 days earlier than ‘Kyoho’. To identify genes controlling early fruit development and ripening in ‘Fengzao’, RNA-Seq profiles of the two cultivars were compared at 8 different berry developmental stages in both berry peel and flesh tissues.MethodsRNA-Seq profiling of berry development between ‘Kyoho’ and ‘Fenzhao’ were obtained using the Illumina HiSeq system and analyzed using various statistical methods. Expression patterns of several selected genes were validated using qRT-PCR.ResultsAbout 447 millions of RNA-Seq sequences were generated from 40 RNA libraries covering various different berry developmental stages of ‘Fengzao’ and ‘Kyoho’. These sequences were mapped to 23,178 and 22,982 genes in the flesh and peel tissues, respectively. While most genes in ‘Fengzao’ and ‘Kyoho’ shared similar expression patterns over different berry developmental stages, there were many genes whose expression were detected only in ‘Fengzao’ or ‘Kyoho’. We observed 10 genes in flesh tissue and 22 genes in peel tissue were differentially expressed at FDR ≤ 0.05 when the mean expression of ‘Fengzao’ and ‘Kyoho’ were compared. The most noticeable one was VIT_214s0030g00950 (a superoxide dismutase gene). This ROS related gene showed lower expression levels in ‘Fengzao’ than ‘Kyoho’ in both peel and flesh tissues across various berry developmental stages with the only exception at véraison. VIT_200s0238g00060 (TMV resistance protein n-like) and VIT_213s0067g01100 (disease resistance protein at3g14460-like) were the two other noticeable genes which were found differentially expressed between the two cultivars in both peel and flesh tissues. GO functional category and KEGG enrichment analysis of DEGs indicated that gene activities related to stress and ROS were altered between the two cultivars in both flesh and peel tissues. Several differentially expressed genes of interest were successfully validated using qRT-PCR.ConclusionsComparative profiling analysis revealed a few dozens of genes which were differentially expressed in the developing berries of ‘Kyoho’ and its early ripening mutant ‘Fengzao’. Further analysis of these differentially expressed genes suggested that gene activities related to ROS and pathogenesis were likely involved in contributing to the early ripening in ‘Fengzao’.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3051-1) contains supplementary material, which is available to authorized users.

Proteomic Analysis of Exosomes and Exosome-Free Conditioned Media From Human Osteosarcoma Cell Lines Reveals Secretion of Proteins Related to Tumor Progression.

Osteosarcomas are the most prevalent bone tumors in pediatric patients, but can also occur later in life. Bone tumors have the potential to metastasize to lung and occasionally other vital organs. To understand how osteosarcoma cells interact with their micro-environment to support bone tumor progression and metastasis, we analyzed secreted proteins and exosomes from three human osteosarcoma cell lines. Exosome isolation was validated by transmission electron microscopy (TEM) and immuno-blotting for characteristic biomarkers (CD63, CD9, and CD81). Exosomal and soluble proteins (less than 100 kDa) were identified by mass spectrometry analysis using nanoLC-MS/MS and classified by functional gene ontology clustering. We identified a secretome set of >3,000 proteins for both fractions, and detected proteins that are either common or unique among the three osteosarcoma cell lines. Protein ontology comparison of proteomes from exosomes and exosome-free fractions revealed differences in the enrichment of functional categories associated with different biological processes, including those related to tumor progression (i.e., angiogenesis, cell adhesion, and cell migration). The secretome characteristics of osteosarcoma cells are consistent with the pathological properties of tumor cells with metastatic potential. J. Cell. Biochem. 118: 351-360, 2017. © 2016 Wiley Periodicals, Inc.

Ni exposure impacts the pool of free Fe and modifies DNA supercoiling via metal-induced oxidative stress in Escherichia coli K-12

The biology of nickel has been widely studied in mammals because of its carcinogenic properties, whereas few studies have been performed in microorganisms. In the present work, changes accompanying stress caused by nickel were evaluated at the cellular level using RNA-Seq in Escherichia coli K-12. Interestingly, a very large number of genes were found to be deregulated by Ni stress. Iron and oxidative stress homeostasis maintenance were among the most highly enriched functional categories, and genes involved in periplasmic copper efflux were among the most highly upregulated. These results suggest that the deregulation of Fe and Cu homeostatic genes is caused by a release of free Cu and Fe ions in the cell which in turn activate the Cu and Fe homeostatic systems. The content of Cu was not significantly affected upon the addition of Ni to the growth medium, nor were the Cus and CopA Cu-efflux systems important for the survival of bacteria under Ni stress In contrast the addition of Ni slightly decreased the amount of cellular Fe and activated the transcription of Fur regulated genes in a Fur-dependent manner. Cu or Fe imbalance together with oxidative stress might affect the structure of DNA. Further experiments revealed that Ni alters the state of DNA folding by causing a relaxed conformation, a phenomenon that is reversible by addition of the antioxidant Tiron or the Fe chelator Dip. The Tiron-reversible DNA relaxation was also observed for Fe and to a lesser extent with Cu but not with Co. DNA supercoiling is well recognized as an integral aspect of gene regulation. Moreover our results show that Ni modifies the expression of several nucleoid-associated proteins (NAPs), important agents of DNA topology and global gene regulation. This is the first report describing the impact of metal-induced oxidative on global regulatory networks.