Ensembl 2009

Simultaneous profiling of native-state proteomes and transcriptomes of neural cell types using proximity labeling

Deep molecular phenotyping of cells at transcriptomic and proteomic levels is an essential first step to understanding cellular contributions to development, aging, injury, and disease. Since proteome and transcriptome level abundances only modestly correlate with each other, complementary profiling of both is needed. We report a novel method called simultaneous protein and RNA -omics (SPARO) to capture the cell type-specific transcriptome and proteome simultaneously from both in vitro and in vivo experimental model systems. This method leverages the ability of biotin ligase, TurboID, to biotinylate cytosolic proteins including ribosomal and RNA-binding proteins, which allows enrichment of biotinylated proteins for proteomics as well as protein-associated RNA for transcriptomics. We validated this approach first using well-controlled in vitro systems to verify that the proteomes and transcriptomes obtained reflect the ground truth, bulk proteomes and transcriptomes. We also show that the effect of a biological stimulus (e.g., neuroinflammatory activation by lipopolysaccharide) can be faithfully captured. We also applied this approach to obtain native-state proteomes and transcriptomes from two key neural cell types, astrocytes and neurons, thereby validating the in vivo application of SPARO. Next, we used these data to interrogate protein-mRNA concordance and discordance across these cell types, providing insights into groups of molecular processes that exhibit uniform or cell type-specific patterns of mRNA-protein discordance.

The molecular dissection of TRIM25's RNA-binding mechanism provides key insights into its antiviral activity

TRIM25 is an RNA-binding ubiquitin E3 ligase with central but poorly understood roles in the innate immune response to RNA viruses. The link between TRIM25's RNA binding and its role in innate immunity has not been established. Thus, we utilized a multitude of biophysical techniques to identify key RNA-binding residues of TRIM25 and developed an RNA-binding deficient mutant (TRIM25-m9). Using iCLIP2 in virus-infected and uninfected cells, we identified TRIM25's RNA sequence and structure specificity, that it binds specifically to viral RNA, and that the interaction with RNA is critical for its antiviral activity.

Oryza CLIMtools: A genome-environment association resource reveals adaptive roles for heterotrimeric G proteins in the regulation of rice agronomic traits

Modern crop varieties display a degree of mismatch between their current distributions and the suitability of the local climate for their productivity. To address this issue, we present Oryza CLIMtools (https://gramene.org/CLIMtools/oryza_v1.0/), the first resource for pan-genome prediction of climate-associated genetic variants in a crop species. Oryza CLIMtools consists of interactive web-based databases that enable the user to (1) explore the local environments of traditional rice varieties (landraces) in South-East Asia and (2) investigate the environment by genome associations for 658 Indica and 283 Japonica rice landrace accessions collected from georeferenced local environments and included in the 3K Rice Genomes Project. We demonstrate the value of these resources by identifying an interplay between flowering time and temperature in the local environment that is facilitated by adaptive natural variation in OsHD2 and disrupted by a natural variant in OsSOC1. Prior quantitative trait locus analysis has suggested the importance of heterotrimeric G proteins in the control of agronomic traits. Accordingly, we analyzed the climate associations of natural variants in the different heterotrimeric G protein subunits. We identified a coordinated role of G proteins in adaptation to the prevailing potential evapotranspiration gradient and revealed their regulation of key agronomic traits, including plant height and seed and panicle length. We conclude by highlighting the prospect of targeting heterotrimeric G proteins to produce climate-resilient crops.

Oryza CLIMtools: A Genome-Environment Association Resource Reveals Adaptive Roles for Heterotrimeric G Proteins in the Regulation of Rice Agronomic Traits

Modern crop varieties display a degree of mismatch between their current distributions and the suitability of the local climate for their productivity. To this end, we present Oryza CLIMtools (https://gramene.org/CLIMtools/oryza_v1.0/), the first resource for pan-genome prediction of climate-associated genetic variants in a crop species. Oryza CLIMtools consists of interactive web-based databases that allow the user to: i) explore the local environments of traditional rice varieties (landraces) in South-Eastern Asia, and; ii) investigate the environment by genome associations for 658 Indica and 283 Japonica rice landrace accessions collected from georeferenced local environments and included in the 3K Rice Genomes Project. We exemplify the value of these resources, identifying an interplay between flowering time and temperature in the local environment that is facilitated by adaptive natural variation in OsHD2 and disrupted by a natural variant in OsSOC1. Prior QTL analysis has suggested the importance of heterotrimeric G proteins in the control of agronomic traits. Accordingly, we analyzed the climate associations of natural variants in the different heterotrimeric G protein subunits. We identified a coordinated role of G proteins in adaptation to the prevailing Potential Evapotranspiration gradient and their regulation of key agronomic traits including plant height and seed and panicle length. We conclude by highlighting the prospect of targeting heterotrimeric G proteins to produce crops that are climate resilient.

Identification and in-silico characterization of splice-site variants from a large cardiogenetic national registry

Splice-site variants in cardiac genes may predispose carriers to potentially lethal arrhythmias. To investigate, we screened 1315 probands and first-degree relatives enrolled in the Canadian Hearts in Rhythm Organization (HiRO) registry. 10% (134/1315) of patients in the HiRO registry carry variants within 10 base-pairs of the intron-exon boundary with 78% (104/134) otherwise genotype negative. These 134 probands were carriers of 57 unique variants. For each variant, American College of Medical Genetics and Genomics (ACMG) classification was revisited based on consensus between nine in silico tools. Due in part to the in silico algorithms, seven variants were reclassified from the original report, with the majority (6/7) downgraded. Our analyses predicted 53% (30/57) of variants to be likely/pathogenic. For the 57 variants, an average of 9 tools were able to score variants within splice sites, while 6.5 tools responded for variants outside these sites. With likely/pathogenic classification considered a positive outcome, the ACMG classification was used to calculate sensitivity/specificity of each tool. Among these, Combined Annotation Dependent Depletion (CADD) had good sensitivity (93%) and the highest response rate (131/134, 98%), dbscSNV was also sensitive (97%), and SpliceAI was the most specific (64%) tool. Splice variants remain an important consideration in gene elusive inherited arrhythmia syndromes. Screening for intronic variants, even when restricted to the ±10 positions as performed here may improve genetic testing yield. We compare 9 freely available in silico tools and provide recommendations regarding their predictive capabilities. Moreover, we highlight several novel cardiomyopathy-associated variants which merit further study.

Multiple relaxases contribute to the horizontal transfer of the virulence plasmids from the tumorigenic bacterium Pseudomonas syringae pv. savastanoi NCPPB 3335

Pseudomonas syringae pv. savastanoi NCPPB 3335 is the causal agent of olive knot disease and contains three virulence plasmids: pPsv48A (pA), 80 kb; pPsv48B (pB), 45 kb, and pPsv48C (pC), 42 kb. Here we show that pB contains a complete MPF_T (previously type IVA secretion system) and a functional origin of conjugational transfer adjacent to a relaxase of the MOB_P family; pC also contains a functional oriT-MOB_P array, whereas pA contains an incomplete MPF_I (previously type IVB secretion system), but not a recognizable oriT. Plasmid transfer occurred on solid and in liquid media, and on leaf surfaces of a non-host plant (Phaseolus vulgaris) with high (pB) or moderate frequency (pC); pA was transferred only occasionally after cointegration with pB. We found three plasmid-borne and three chromosomal relaxase genes, although the chromosomal relaxases did not contribute to plasmid dissemination. The MOB_P relaxase genes of pB and pC were functionally interchangeable, although with differing efficiencies. We also identified a functional MOB_Q mobilization region in pC, which could only mobilize this plasmid. Plasmid pB could be efficiently transferred to strains of six phylogroups of P. syringae sensu lato, whereas pC could only be mobilized to two strains of phylogroup 3 (genomospecies 2). In two of the recipient strains, pB was stably maintained after 21 subcultures in liquid medium. The carriage of several relaxases by the native plasmids of P. syringae impacts their transfer frequency and, by providing functional diversity and redundancy, adds robustness to the conjugation system.

Domain Evolution of Vertebrate Blood Coagulation Cascade Proteins

Vertebrate blood coagulation is controlled by a cascade containing more than 20 proteins. The cascade proteins are found in the blood in their zymogen forms and when the cascade is triggered by tissue damage, zymogens are activated and in turn activate their downstream proteins by serine protease activity. In this study, we examined proteomes of 21 chordates, of which 18 are vertebrates, to reveal the modular evolution of the blood coagulation cascade. Additionally, two Arthropoda species were used to compare domain arrangements of the proteins belonging to the hemolymph clotting and the blood coagulation cascades. Within the vertebrate coagulation protein set, almost half of the studied proteins are shared with jawless vertebrates. Domain similarity analyses revealed that there are multiple possible evolutionary trajectories for each coagulation protein. During the evolution of higher vertebrate clades, gene and genome duplications led to the formation of other coagulation cascade proteins.

RFfiller: a robust and fast statistical algorithm for gap filling in draft genomes

Numerous published genomes contain gaps or unknown sequences. Gap filling is a critical final step in de novo genome assembly, particularly for large genomes. While certain computational approaches partially address the problem, others have shortcomings regarding the draft genome's dependability and correctness (high rates of mis-assembly at gap-closing sites and high error rates). While it is well established that genomic repeats result in gaps, many sequence reads originating from repeat-related gaps are typically missed by existing approaches. A fast and reliable statistical algorithm for closing gaps in a draft genome is presented in this paper. It utilizes the alignment statistics between scaffolds, contigs, and paired-end reads to generate a Markov chain that appropriately assigns contigs or long reads to scaffold gap regions (only corrects candidate regions), resulting in accurate and efficient gap closure. To reconstruct the missing component between the two ends of the same insert, the RFfiller meticulously searches for valid overlaps (in repeat regions) and generates transition tables for similar reads, allowing it to make a statistical guess at the missing sequence. Finally, in our experiments, we show that the RFfiller's gap-closing accuracy is better than that of other publicly available tools when sequence data from various organisms are used. Assembly benchmarks were used to validate RFfiller. Our findings show that RFfiller efficiently fills gaps and that it is especially effective when the gap length is longer. We also show that the RFfiller outperforms other gap closing tools currently on the market.

Analysis of the Batch Effect Due to Sequencing Center in Population Statistics Quantifying Rare Events in the 1000 Genomes Project

The 1000 Genomes Project (1000G) is one of the most popular whole genome sequencing datasets used in different genomics fields and has boosting our knowledge in medical and population genomics, among other fields. Recent studies have reported the presence of ghost mutation signals in the 1000G. Furthermore, studies have shown that these mutations can influence the outcomes of follow-up studies based on the genetic variation of 1000G, such as single nucleotide variants (SNV) imputation. While the overall effect of these ghost mutations can be considered negligible for common genetic variants in many populations, the potential bias remains unclear when studying low frequency genetic variants in the population. In this study, we analyze the effect of the sequencing center in predicted loss of function (LoF) alleles, the number of singletons, and the patterns of archaic introgression in the 1000G. Our results support previous studies showing that the sequencing center is associated with LoF and singletons independent of the population that is considered. Furthermore, we observed that patterns of archaic introgression were distorted for some populations depending on the sequencing center. When analyzing the frequency of SNPs showing extreme patterns of genotype differentiation among centers for CEU, YRI, CHB, and JPT, we observed that the magnitude of the sequencing batch effect was stronger at MAF < 0.2 and showed different profiles between CHB and the other populations. All these results suggest that data from 1000G must be interpreted with caution when considering statistics using variants at low frequency.

Transcript-Specific Loss-of-Function Variants in VPS16 Are Enriched in Patients With Dystonia

Background and Objectives

Our objective was to improve rare variant interpretation using statistical measures as well as publicly accessible annotation of expression levels and tissue specificity of different splice isoforms. We describe rare VPS16 variants observed in patients with dystonia and patients without dystonia, elaborate on our interpretation of VPS16 variants affecting different transcripts, and provide detailed clinical description of the movement disorder caused by VPS16 variants.

Methods

In-house exome and genome data sets (n = 11,539) were screened for rare heterozygous missense and putative loss-of-function (pLoF) variants in VPS16. Using pext (proportion expressed across transcripts) values from the Genome Aggregation Database (gnomAD), we differentiated variants affecting weakly and highly expressed exons/transcripts and applied statistical measures to systematically identify disease-associated genetic variation among patients with dystonia (n = 280).

Results

Six different heterozygous pLoFs in VPS16 transcripts were identified in 13 individuals. Three of these pLoFs occurred in 9 individuals with different phenotypes, and 3 pLoFs were identified in 4 unrelated individuals with early-onset dystonia. Although pLoFs were enriched in the dystonia cohort (n = 280; p = 2.04 × 10⁻⁴; 4/280 cases vs 9/11,259 controls; Fisher exact test), it was not exome-wide significant. According to the pext values in gnomAD, all 3 pLoFs observed in the patients with dystonia were located in the highly expressed canonical transcript ENST00000380445.3, whereas 2 of 3 pLoFs detected in 8 individuals without dystonia were located in the first exon of the noncanonical transcript ENST00000380443.3 that is weakly expressed across all tissues. Taking these biological implications into account, pLoFs involving the canonical transcript were exome-wide significantly enriched in patients with dystonia (p = 1.67 × 10⁻⁶; 4/280 cases vs 1/11,259 controls; Fisher exact test). All VPS16 patients showed mild progressive dystonia with writer's cramp as the presenting symptom between age 7 and 34 years (mean 20 years) that often progressed to generalized dystonia and was even accompanied by hyperkinetic movements and myoclonus in 1 patient.

Discussion

Our data provide strong evidence for VPS16 pLoFs to be implicated in dystonia and knowledge on exon resolution expression levels as well as statistical measures proved to be useful for variant interpretation.

Multi-Neighborhood Learning for Global Alignment in Biological Networks

The global alignment of biological networks (GABN) aims to find an optimal alignment between proteins across species, such that both the biological structures and the topological structures of the proteins are maximally conserved. The research on GABN has attracted great attention due to its applications on species evolution, orthology detection and genetic analyses. Most of the existing methods for GABN are difficult to obtain a good tradeoff between the conservation of the biological structures and topological structures. In this paper, we propose a multi-neighborhood learning method for solving GABN (called as CLMNA). CLMNA first models GABN as an optimization of a weighted similarity which evaluates the conserved biological and topological similarities of an alignment, and then it combines a first-proximity, second-proximity and individual-aware proximity learning algorithm to solve the modeled problem. Finally, systematic experiments on 10 pairs of biological networks across 5 species show the superiority of CLMNA over the state-of-the-art network alignment algorithms. They also validate the effectiveness of CLMNA as a refinement method on improving the performance of the compared algorithms.

Genome-wide selection of discriminant SNP markers for breed assignment in indigenous sheep breeds

The assignment of an individual to the true population of origin is one of the most important applications of genomic data for practical use in animal breeding. The aim of this study was to develop a statistical method and then, to identify the minimum number of informative SNP markers from high-throughput genotyping data that would be able to trace the true breed of unknown samples in indigenous sheep breeds. The total numbers of 217 animals were genotyped using Illumina OvineSNP50K BeadChip in Zel, Lori-Bakhtiari, Afshari, Moqani, Qezel and a wild-type Iranian sheep breed. After SNP quality check, the principal component analysis (PCA) was used to determine how the animals allocated to the groups using all genotyped markers. The results revealed that the first principal component (PC1) separated out the two domestic and wild sheep breeds, and all domestic breeds were separated from each other for PC2. The genetic distance between different breeds was calculated using FST and Reynold methods and the results showed that the breeds were well differentiated. A statistical method was developed using the stepwise discriminant analysis (SDA) and the linear discriminant analysis (LDA) to reduce the number of SNPs for discriminating 6 different Iranian sheep populations and K-fold cross-validation technique was employed to evaluate the potential of a selected subset of SNPs in assignment success rate. The procedure selected reduced pools of markers into 201 SNPs that were able to exactly discriminate all sheep populations with 100% accuracy. Moreover, a discriminate analysis of principal components (DAPC) developed using 201 linearly independent SNPs revealed that these markers were able to assign all individuals into true breed. Finally, these 201 identified SNPs were successfully used in an independent out-group breed consisting of 96 samples of Baluchi sheep breed and the results indicated that these markers are able to correctly allocate all unknown samples to true population of origin. In general, the results of this study indicated that the combined use of the SDA and LDA techniques represents an efficient strategy for selecting a reduced pool of highly discriminant markers.

Databases for Protein-Protein Interactions

Protein-protein interaction networks have a crucial role in biological processes. Proteins perform multiple functions in forming physical and functional interactions in cellular systems. Information concerning an enormous number of protein interactions in a wide range of species has accumulated and has been integrated into various resources for molecular biology and systems biology. This chapter provides a review of the representative databases and the major computational methods used for protein-protein interactions.

Emerging Classes of Small Non-Coding RNAs With Potential Implications in Diabetes and Associated Metabolic Disorders

Most of the sequences in the human genome do not code for proteins but generate thousands of non-coding RNAs (ncRNAs) with regulatory functions. High-throughput sequencing technologies and bioinformatic tools significantly expanded our knowledge about ncRNAs, highlighting their key role in gene regulatory networks, through their capacity to interact with coding and non-coding RNAs, DNAs and proteins. NcRNAs comprise diverse RNA species, including amongst others PIWI-interacting RNAs (piRNAs), involved in transposon silencing, and small nucleolar RNAs (snoRNAs), which participate in the modification of other RNAs such as ribosomal RNAs and transfer RNAs. Recently, a novel class of small ncRNAs generated from the cleavage of tRNAs or pre-tRNAs, called tRNA-derived small RNAs (tRFs) has been identified. tRFs have been suggested to regulate protein translation, RNA silencing and cell survival. While for other ncRNAs an implication in several pathologies is now well established, the potential involvement of piRNAs, snoRNAs and tRFs in human diseases, including diabetes, is only beginning to emerge. In this review, we summarize fundamental aspects of piRNAs, snoRNAs and tRFs biology. We discuss their biogenesis while emphasizing on novel sequencing technologies that allow ncRNA discovery and annotation. Moreover, we give an overview of genomic approaches to decrypt their mechanisms of action and to study their functional relevance. The review will provide a comprehensive landscape of the regulatory roles of these three types of ncRNAs in metabolic disorders by reporting their differential expression in endocrine pancreatic tissue as well as their contribution to diabetes incidence and diabetes-underlying conditions such as inflammation. Based on these discoveries we discuss the potential use of piRNAs, snoRNAs and tRFs as promising therapeutic targets in metabolic disorders.

Diversity analysis, runs of homozygosity and genomic inbreeding reveal recent selection in Blanco Orejinegro cattle

Blanco Orejinegro (BON) cattle have 500 years of adaptation to the Colombian tropic, but little is known about their genetic history. Our aim was to estimate levels of linkage disequilibrium (LD), effective population size (Ne), genomic inbreeding for runs of homozygosity (F_ROH ), genomic relation matrix (F_GRM ), excess of homozygotes (F_HOM ) and pedigree information (F_PEDCOMP ) and to characterize the runs of homozygosity (ROH), searching for selection signatures. A total of 419 BON animals were genotyped, 70 with a 150K chip and 349 with a 50K chip. Next, an imputation to 50K was performed, and, after editing, databases of 40K were obtained. The PLINK v1.90 and R programs were used to estimate LD, ROH, F_ROH and F_HOM . The SNeP v1.1 program was used to obtain Ne, and PreGSf90 was used to elaborate the scaled G matrix. The MTDFNRM program was used to estimate F_PEDCOMP . The LD mean as r² at 1 Mb was 0.21 (r²  > 0.30 at a distance of 96.72kb), and Ne was 123 ± 1. A total of 7,652 homozygous segments were obtained, with a mean of 18.35 ± 0.55 ROH/animal. Most of the genome was covered by long ROHs (ROH_{>8 Mb}  = 4.86%), indicating significant recent inbreeding. The average inbreeding coefficient for F_PEDCOM , F_GRM , F_HOM and F_ROH was 4.41%, 4.18%, 5.58% and 6.78%, respectively. The highest correlation was observed between F_HOM and F_ROH (0.95). ROH hotspots/islands were defined using the extreme values of a box plot that was generated, and correspond to QTLs related to milk yield (55.11%), external appearance (13.47%), production (13.30%), reproduction (8.15%), health (5.24%) and meat carcass (4.74%).

Establishment and application of information resource of mutant mice in RIKEN BioResource Research Center

Online databases are crucial infrastructures to facilitate the wide effective and efficient use of mouse mutant resources in life sciences. The number and types of mouse resources have been rapidly growing due to the development of genetic modification technology with associated information of genomic sequence and phenotypes. Therefore, data integration technologies to improve the findability, accessibility, interoperability, and reusability of mouse strain data becomes essential for mouse strain repositories. In 2020, the RIKEN BioResource Research Center released an integrated database of bioresources including, experimental mouse strains, Arabidopsis thaliana as a laboratory plant, cell lines, microorganisms, and genetic materials using Resource Description Framework-related technologies. The integrated database shows multiple advanced features for the dissemination of bioresource information. The current version of our online catalog of mouse strains which functions as a part of the integrated database of bioresources is available from search bars on the page of the Center (https://brc.riken.jp) and the Experimental Animal Division (https://mus.brc.riken.jp/) websites. The BioResource Research Center also released a genomic variation database of mouse strains established in Japan and Western Europe, MoG⁺ (https://molossinus.brc.riken.jp/mogplus/), and a database for phenotype-phenotype associations across the mouse phenome using data from the International Mouse Phenotyping Platform. In this review, we describe features of current version of databases related to mouse strain resources in RIKEN BioResource Research Center and discuss future views.

Clinical and molecular evaluation of 13 Brazilian patients with Gomez-López-Hernández syndrome

We aim to characterize patients with Gomez-López-Hernández syndrome (GLHS) clinically and to investigate them molecularly. A clinical protocol, including a morphological and neuropsychological assessment, was applied to 13 patients with GLHS. Single-nucleotide polymorphism (SNP) array and whole-exome sequencing were undertaken; magnetic resonance imaging was performed in 12 patients, including high-resolution, heavily T2-weighted sequences (HRT2) in 6 patients to analyze the trigeminal nerves. All patients presented alopecia; two did not present rhombencephalosynapsis (RES); trigeminal anesthesia was present in 5 of the 11 patients (45.4%); brachycephaly/brachyturricephaly and mid-face retrusion were found in 84.6 and 92.3% of the patients, respectively. One patient had intellectual disability. HRT2 sequences showed trigeminal nerve hypoplasia in four of the six patients; all four had clinical signs of trigeminal anesthesia. No common candidate gene was found to explain GLHS phenotype. RES does not seem to be an obligatory finding in respect of GLHS diagnosis. We propose that a diagnosis of GLHS should be considered in patients with at least two of the following criteria: focal non-scarring alopecia, rhombencephalosynapsis, craniofacial anomalies (brachyturrycephaly, brachycephaly or mid-face retrusion), trigeminal anesthesia or anatomic abnormalities of the trigeminal nerve. Studies focusing on germline whole genome sequencing or DNA and/or RNA sequencing of the alopecia tissue may be the next step for the better understanding of GLHS etiology.

Genes ptz and idi, Coding for Cytokinin Biosynthesis Enzymes, Are Essential for Tumorigenesis and In Planta Growth by P. syringae pv. savastanoi NCPPB 3335

The phytopathogenic bacterium Pseudomonas syringae pv. savastanoi elicits aerial tumors on olive plants and is also able to synthesize large amounts of auxins and cytokinins. The auxin indoleacetic acid was shown to be required for tumorigenesis, but there is only correlational evidence suggesting a role for cytokinins. The model strain NCPPB 3335 contains two plasmid-borne genes coding for cytokinin biosynthesis enzymes: ptz, for an isopentenyl transferase and idi, for an isopentenyl-diphosphate delta-isomerase. Phylogenetic analyses showed that carriage of ptz and idi is not strictly associated with tumorigenic bacteria, that both genes were linked when first acquired by P. syringae, and that a different allele of ptz has been independently acquired by P. syringae pv. savastanoi and closely related bacteria. We generated mutant derivatives of NCPPB 3335 cured of virulence plasmids or with site-specific deletions of genes ptz and/or idi and evaluated their virulence in lignified and micropropagated olive plants. Strains lacking ptz, idi, or both produced tumors with average volumes up to 29 times smaller and reached populations up to two orders of magnitude lower than those induced by strain NCPPB 3335; these phenotypes reverted by complementation with the cloned genes. Trans-zeatin was the most abundant cytokinin in culture filtrates of NCPPB 3335. Deletion of gene ptz abolished biosynthesis of trans-zeatin and dihydrozeatin, whereas a reduced but significant amount of isopentenyladenine was still detected in the medium, suggesting the existence of other genes contributing to cytokinin biosynthesis in P. syringae. Conversely, extracts from strains lacking gene idi contained significantly higher amounts of trans-zeatin than extracts from the wild-type strain but similar amounts of the other cytokinins. This suggests that Idi might promote tumorigenesis by ensuring the biosynthesis of the most active cytokinin forms, their correct balance in planta, or by regulating the expression of other virulence genes. Therefore, gene ptz, but not gene idi, is essential for the biosynthesis of high amounts of cytokinins in culture; however, both ptz and idi are individually essential for the adequate development of tumors on olive plants by Psv NCPPB 3335.

Gomez-López-Hernández syndrome: A case report with clinical and molecular evaluation and literature review

Gomez-López-Hernández syndrome (GLHS) is characterized by rhombencephalosynapsis (RES), alopecia, trigeminal anesthesia and a distinctive phenotype, including brachyturricephaly. It has been suggested that GLHS should be considered as part of the spectrum of RES-associated conditions that include alopecia, trigeminal anesthesia, and craniofacial anomalies, rather than a distinct entity. To the best of our knowledge, 57 patients with GLHS have been described. Despite its first description in 1979, the etiology of this syndrome remains unknown. Here, we describe, to our knowledge, the first case of a patient with GLHS who was molecularly evaluated and had been prenatally exposed to misoprostol. We also reviewed the clinical and morphological features of the patients described to date to better delineate the phenotype and focus on any evidence for adverse pregnancy outcomes or exposure, including teratogens.

Common homozygosity for predicted loss-of-function variants reveals both redundant and advantageous effects of dispensable human genes

Humans homozygous or hemizygous for variants predicted to cause a loss of function (LoF) of the corresponding protein do not necessarily present with overt clinical phenotypes. We report here 190 autosomal genes with 207 predicted LoF variants, for which the frequency of homozygous individuals exceeds 1% in at least one human population from five major ancestry groups. No such genes were identified on the X and Y chromosomes. Manual curation revealed that 28 variants (15%) had been misannotated as LoF. Of the 179 remaining variants in 166 genes, only 11 alleles in 11 genes had previously been confirmed experimentally to be LoF. The set of 166 dispensable genes was enriched in olfactory receptor genes (41 genes). The 41 dispensable olfactory receptor genes displayed a relaxation of selective constraints similar to that observed for other olfactory receptor genes. The 125 dispensable nonolfactory receptor genes also displayed a relaxation of selective constraints consistent with greater redundancy. Sixty-two of these 125 genes were found to be dispensable in at least three human populations, suggesting possible evolution toward pseudogenes. Of the 179 LoF variants, 68 could be tested for two neutrality statistics, and 8 displayed robust signals of positive selection. These latter variants included a known FUT2 variant that confers resistance to intestinal viruses, and an APOL3 variant involved in resistance to parasitic infections. Overall, the identification of 166 genes for which a sizeable proportion of humans are homozygous for predicted LoF alleles reveals both redundancies and advantages of such deficiencies for human survival.

In Silico Exploration of Conformational Dynamics and Novel Inhibitors for Targeting MEF2-Associated Transcriptional Activity

Myocyte enhancer factor 2 (MEF2; MEF2A-MEF2D) transcription factors regulate gene expression in a variety of developmental processes by binding to AT-rich DNA motifs via highly conserved N-terminal extensions known as MADS-box and MEF2 domains. Despite the fact that MEF2 proteins exhibit high similarity at their N-terminal regions and share a common consensus DNA binding motif, their functional preferences may vary significantly in the adjacent regions to the DNA binding core segment. The current study delineates the conformational paradigm, clustered recognition, and comparative DNA binding preferences for MEF2A and MEF2B-specific MADS-box/MEF2 domains at the YTA(A/T)4TAR consensus motif. In both MEF2A and MEF2B proteins, α1-helix plays a crucial role through acquiring more flexibility by attaining loop conformation. In comparison to apo-MEF2, an outward disposition of the distal portion of α1-helix and movement of its proximal part to β1 allows synergistic repositioning of the α1-α2 linker, C-terminal region, and MEF2 domain, resulting in the formation of a hydrophobic groove for DNA binding. In both instances, conformational switching of the helical content is the main contributing factor while preserving the overall β-topology to maintain the inside-out conformation of subdivided α1-helix flip. Multivariate statistical analysis reveals that MEF2B obscures less accessible conformational space for DNA binding as compared to the MEF2A-DNA complex. The presence of similar structural requirements and conserved residues including Arg10, Phe21, and Arg24 in accentuating the MEF2-specific DNA recognition mechanism led us to perform structure-based virtual screening for isolating novel inhibitors that are able to target MEF2-DNA binding regions. The top hits (acetamide, benzamide, carboxamide, and enamide) obtained through preliminary assay were scrutinized to binding potential analysis at the MEF2-DNA binding groove, energy values, absorption, distribution, toxicity, and Lipinski's rule of five assessments. Based on these findings, we propose valuable active drug-like molecules for selective applications against MEF2A and MEF2B. The current study may help in uncovering the atomistic-level mechanistic DNA binding patterns of MEF2 proteins, and data may be valuable in devising effective therapeutic strategies for MEF2-associated disorders.

Detection of Cell Surface Ligands for Human Synovial γδ T Cells

Lack of understanding of the nature and physiological regulation of γδ T cell ligands has considerably hampered full understanding of the function of these cells. We developed an unbiased approach to identify human γδ T cells ligands by the production of a soluble TCR-γδ (sTCR-γδ) tetramer from a synovial Vδ1 γδ T cell clone from a Lyme arthritis patient. The sTCR-γδ was used in flow cytometry to initially define the spectrum of ligand expression by both human tumor cell lines and certain human primary cells. Analysis of diverse tumor cell lines revealed high ligand expression on several of epithelial or fibroblast origin, whereas those of hematopoietic origin were largely devoid of ligand. This allowed a bioinformatics-based identification of candidate ligands using RNAseq data from each tumor line. We further observed that whereas fresh monocytes and T cells expressed low to negligible levels of TCR-γδ ligands, activation of these cells resulted in upregulation of surface ligand expression. Ligand upregulation on monocytes was partly dependent upon IL-1β. The sTCR-γδ tetramer was then used to bind candidate ligands from lysates of activated monocytes and analyzed by mass spectrometry. Surface TCR-γδ ligand was eliminated by treatment with trypsin or removal of glycosaminoglycans, and also suppressed by inhibition of endoplasmic reticulum-Golgi transport. Of particular interest was that inhibition of glycolysis also blocked TCR-γδ ligand expression. These findings demonstrate the spectrum of ligand(s) expression for human synovial Vδ1 γδ T cells as well as the physiology that regulates their expression.

Evolutionary lability in Hox cluster structure and gene expression in Anolis lizards

Hox genes orchestrate development by patterning the embryonic axis. Vertebrate Hox genes are arranged in four compact clusters, and the spacing between genes is assumed to be crucial for their function. The genomes of squamate reptiles are unusually rich and variable in transposable elements (TEs), and it has been suggested that TE invasion is responsible for the Hox cluster expansion seen in snakes and lizards. Using de novo TE prediction on 17 genomes of lizards and snakes, I show that TE content of Hox clusters are generally 50% lower than genome‐wide TE levels. However, two distantly related lizards of the species‐rich genus Anolis have Hox clusters with a TE content that approaches genomic levels. The age distribution of TEs in Anolis lizards revealed that peaks of TE activity broadly coincide with speciation events. In accordance with theoretical models of Hox cluster regulation, I find that Anolis species with many TEs in their Hox clusters show aberrant Hox gene expression patterns, suggesting a functional link between TE accumulation and embryonic development. These results are consistent with the hypothesis that TEs play a role in developmental processes as well as in evolutionary diversifications.

Extensive post-transcriptional buffering of gene expression in the response to severe oxidative stress in baker's yeast

Cells responds to diverse stimuli by changing the levels of specific effector proteins. These changes are usually examined using high throughput RNA sequencing data (RNA-Seq); transcriptional regulation is generally assumed to directly influence protein abundances. However, the correlation between RNA-Seq and proteomics data is in general quite limited owing to differences in protein stability and translational regulation. Here we perform RNA-Seq, ribosome profiling and proteomics analyses in baker's yeast cells grown in rich media and oxidative stress conditions to examine gene expression regulation at various levels. With the exception of a small set of genes involved in the maintenance of the redox state, which are regulated at the transcriptional level, modulation of protein expression is largely driven by changes in the relative ribosome density across conditions. The majority of shifts in mRNA abundance are compensated by changes in the opposite direction in the number of translating ribosomes and are predicted to result in no net change at the protein level. We also identify a subset of mRNAs which is likely to undergo specific translational repression during stress and which includes cell cycle control genes. The study suggests that post-transcriptional buffering of gene expression may be more common than previously anticipated.

De novo assembly of the goldfish (Carassius auratus) genome and the evolution of genes after whole-genome duplication

For over a thousand years, the common goldfish (Carassius auratus) was raised throughout Asia for food and as an ornamental pet. As a very close relative of the common carp (Cyprinus carpio), goldfish share the recent genome duplication that occurred approximately 14 million years ago in their common ancestor. The combination of centuries of breeding and a wide array of interesting body morphologies provides an exciting opportunity to link genotype to phenotype and to understand the dynamics of genome evolution and speciation. We generated a high-quality draft sequence and gene annotations of a "Wakin" goldfish using 71X PacBio long reads. The two subgenomes in goldfish retained extensive synteny and collinearity between goldfish and zebrafish. However, genes were lost quickly after the carp whole-genome duplication, and the expression of 30% of the retained duplicated gene diverged substantially across seven tissues sampled. Loss of sequence identity and/or exons determined the divergence of the expression levels across all tissues, while loss of conserved noncoding elements determined expression variance between different tissues. This assembly provides an important resource for comparative genomics and understanding the causes of goldfish variants.

Asymmetric paralog evolution between the "cryptic" gene Bmp16 and its well-studied sister genes Bmp2 and Bmp4

The vertebrate gene repertoire is characterized by “cryptic” genes whose identification has been hampered by their absence from the genomes of well-studied species. One example is the Bmp16 gene, a paralog of the developmental key genes Bmp2 and -4. We focus on the Bmp2/4/16 group of genes to study the evolutionary dynamics following gen(om)e duplications with special emphasis on the poorly studied Bmp16 gene. We reveal the presence of Bmp16 in chondrichthyans in addition to previously reported teleost fishes and reptiles. Using comprehensive, vertebrate-wide gene sampling, our phylogenetic analysis complemented with synteny analyses suggests that Bmp2, -4 and -16 are remnants of a gene quartet that originated during the two rounds of whole-genome duplication (2R-WGD) early in vertebrate evolution. We confirm that Bmp16 genes were lost independently in at least three lineages (mammals, archelosaurs and amphibians) and report that they have elevated rates of sequence evolution. This finding agrees with their more “flexible” deployment during development; while Bmp16 has limited embryonic expression domains in the cloudy catshark, it is broadly expressed in the green anole lizard. Our study illustrates the dynamics of gene family evolution by integrating insights from sequence diversification, gene repertoire changes, and shuffling of expression domains.

Ethnicity-Specific Skeletal Muscle Transcriptional Signatures and Their Relevance to Insulin Resistance in Singapore

CONTEXT

Insulin resistance (IR) and obesity differ among ethnic groups in Singapore, with the Malays more obese yet less IR than Asian-Indians. However, the molecular basis underlying these differences is not clear.

OBJECTIVE

As the skeletal muscle (SM) is metabolically relevant to IR, we investigated molecular pathways in SM that are associated with ethnic differences in IR, obesity, and related traits.

DESIGN, SETTING, AND MAIN OUTCOME MEASURES

We integrated transcriptomic, genomic, and phenotypic analyses in 156 healthy subjects representing three major ethnicities in the Singapore Adult Metabolism Study.

PATIENTS

This study contains Chinese (n = 63), Malay (n = 51), and Asian-Indian (n = 42) men, aged 21 to 40 years, without systemic diseases.

RESULTS

We found remarkable diversity in the SM transcriptome among the three ethnicities, with >8000 differentially expressed genes (40% of all genes expressed in SM). Comparison with blood transcriptome from a separate Singaporean cohort showed that >95% of SM expression differences among ethnicities were unique to SM. We identified a network of 46 genes that were specifically downregulated in Malays, suggesting dysregulation of components of cellular respiration in SM of Malay individuals. We also report 28 differentially expressed gene clusters, four of which were also enriched for genes that were found in genome-wide association studies of metabolic traits and disease and correlated with variation in IR, obesity, and related traits.

CONCLUSION

We identified extensive gene-expression changes in SM among the three Singaporean ethnicities and report specific genes and molecular pathways that might underpin and explain the differences in IR among these ethnic groups.

The toxic guardians - multiple toxin-antitoxin systems provide stability, avoid deletions and maintain virulence genes of Pseudomonas syringae virulence plasmids

Background

Pseudomonas syringae is a γ-proteobacterium causing economically relevant diseases in practically all cultivated plants. Most isolates of this pathogen contain native plasmids collectively carrying many pathogenicity and virulence genes. However, P. syringae is generally an opportunistic pathogen primarily inhabiting environmental reservoirs, which could exert a low selective pressure for virulence plasmids. Additionally, these plasmids usually contain a large proportion of repeated sequences, which could compromise plasmid integrity. Therefore, the identification of plasmid stability determinants and mechanisms to preserve virulence genes is essential to understand the evolution of this pathogen and its adaptability to agroecosystems.

Results

The three virulence plasmids of P. syringae pv. savastanoi NCPPB 3335 contain from one to seven functional stability determinants, including three highly active toxin-antitoxin systems (TA) in both pPsv48A and pPsv48C. The TA systems reduced loss frequency of pPsv48A by two orders of magnitude, whereas one of the two replicons of pPsv48C likely confers stable inheritance by itself. Notably, inactivation of the TA systems from pPsv48C exposed the plasmid to high-frequency deletions promoted by mobile genetic elements. Thus, recombination between two copies of MITEPsy2 caused the deletion of an 8.3 kb fragment, with a frequency of 3.8 ± 0.3 × 10^− 3. Likewise, one-ended transposition of IS801 generated plasmids containing deletions of variable size, with a frequency of 5.5 ± 2.1 × 10^− 4, of which 80% had lost virulence gene idi. These deletion derivatives were stably maintained in the population by replication mediated by repJ, which is adjacent to IS801. IS801 also promoted deletions in plasmid pPsv48A, either by recombination or one-ended transposition. In all cases, functional TA systems contributed significantly to reduce the occurrence of plasmid deletions in vivo.

Conclusions

Virulence plasmids from P. syringae harbour a diverse array of stability determinants with a variable contribution to plasmid persistence. Importantly, we showed that multiple plasmid-borne TA systems have a prominent role in preserving plasmid integrity and ensuring the maintenance of virulence genes in free-living conditions. This strategy is likely widespread amongst native plasmids of P. syringae and other bacteria.

Electronic supplementary material

The online version of this article (10.1186/s13100-019-0149-4) contains supplementary material, which is available to authorized users.

Small Nucleolar RNAs Tell a Different Tale

Transcribing RNA Polymerase II interacts with multiple factors that orchestrate maturation and stabilisation of messenger RNA. For the majority of noncoding RNAs, the polymerase complex employs entirely different strategies, which usually direct the nascent transcript to ribonucleolytic degradation. However, some noncoding RNA classes use endo- and exonucleases to achieve functionality. Here we review processing of small nucleolar RNAs that are transcribed by RNA Polymerase II as precursors, and whose 5' and 3' ends undergo processing to release mature, functional molecules. The maturation strategies of these noncoding RNAs in various organisms follow a similar pattern but employ different factors and are strictly correlated with genomic organisation of their genes.

Risdiplam distributes and increases SMN protein in both the central nervous system and peripheral organs

Spinal muscular atrophy (SMA) is a rare, inherited neuromuscular disease caused by deletion and/or mutation of the Survival of Motor Neuron 1 (SMN1) gene. A second gene, SMN2, produces low levels of functional SMN protein that are insufficient to fully compensate for the lack of SMN1. Risdiplam (RG7916; RO7034067) is an orally administered, small-molecule SMN2 pre-mRNA splicing modifier that distributes into the central nervous system (CNS) and peripheral tissues. To further explore risdiplam distribution, we assessed in vitro characteristics and in vivo drug levels and effect of risdiplam on SMN protein expression in different tissues in animal models. Total drug levels were similar in plasma, muscle, and brain of mice (n = 90), rats (n = 148), and monkeys (n = 24). As expected mechanistically based on its high passive permeability and not being a human multidrug resistance protein 1 substrate, risdiplam CSF levels reflected free compound concentration in plasma in monkeys. Tissue distribution remained unchanged when monkeys received risdiplam once daily for 39 weeks. A parallel dose-dependent increase in SMN protein levels was seen in CNS and peripheral tissues in two SMA mouse models dosed with risdiplam. These in vitro and in vivo preclinical data strongly suggest that functional SMN protein increases seen in patients' blood following risdiplam treatment should reflect similar increases in functional SMN protein in the CNS, muscle, and other peripheral tissues.

The Biological Influence and Clinical Relevance of Polymorphism Within the NKG2D Ligands

NKG2D is a major regulator of the activity of cytotoxic cells and interacts with eight different ligands (NKG2DL) from two families of MIC and ULBP proteins. The selective forces that drove evolution of NKG2DL are uncertain, but are likely to have been dominated by infectious disease and cancer. Of interest, NKG2DL are some of the most polymorphic genes outside the MHC locus and the study of these is uncovering a range of novel observations regarding the structure and function of NKG2DL. Polymorphism is present within all NKG2DL members and varies markedly within different populations. Allelic variation influences functional responses through three major mechanisms. First, it may drive differential levels of protein expression, modulate subcellular trafficking, or regulate release of soluble isoforms. In addition, it may alter the affinity of interaction with NKG2D or modulate cytotoxic activity from the target cell. In particular, ligands with high affinity for NKG2D are associated with down regulation of this protein on the effector cell, effectively limiting cytotoxic activity in a negative-feedback circuit. Given these observations, it is not surprising that NKG2DL alleles are associated with relative risk for development of several clinical disorders and the critical role of the NKG2D:NKG2DL interaction is demonstrated in many murine models. Increased understanding of the biophysical and functional consequences of this polymorphism is likely to provide insights into novel immunotherapeutic approaches.

Chromosomal instability-induced senescence potentiates cell non-autonomous tumourigenic effects

Chromosomal instability (CIN), a high rate of chromosome loss or gain, is often associated with poor prognosis and drug resistance in cancers. Aneuploid, including near-polyploid, cells contain an abnormal number of chromosomes and exhibit CIN. The post-mitotic cell fates following generation of different degrees of chromosome mis-segregation and aneuploidy are unclear. Here we used aneuploidy inducers, nocodazole and reversine, to create different levels of aneuploidy. A higher extent of aneuploid and near-polyploid cells in a given population led to senescence. This was in contrast to cells with relatively lower levels of abnormal ploidy that continued to proliferate. Our findings revealed that senescence was accompanied by DNA damage and robust p53 activation. These senescent cells acquired the senescence-associated secretory phenotype (SASP). Depletion of p53 reduced the number of senescent cells with concomitant increase in cells undergoing DNA replication. Characterisation of these SASP factors demonstrated that they conferred paracrine pro-tumourigenic effects such as invasion, migration and angiogenesis both in vitro and in vivo. Finally, a correlation between increased aneuploidy and senescence was observed at the invasive front in breast carcinomas. Our findings demonstrate functional non-equivalence of discernable aneuploidies on tumourigenesis and suggest a cell non-autonomous mechanism by which aneuploidy-induced senescent cells and SASP can affect the tumour microenvironment to promote tumour progression.

Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency

Transaldolase deficiency (MIM#: 606003) is a rare autosomal recessive defect in the pentose phosphate pathway. Affected individuals are at risk for progressive liver failure and hepatocarcinoma. In the transaldolase-deficient mouse model (Taldo1 ^-/-), these hepatic complications are accentuated by oxidative stress related to acetaminophen administration. We report a 13-month-old transaldolase-deficient male who developed mild liver failure after receiving standard doses of acetaminophen during a febrile respiratory syncytial virus infection. He was admitted for respiratory distress with neutropenia and thrombocytopenia, but developed an enlarged nodular liver with accompanying splenomegaly and rising alpha-fetoprotein which peaked 2 weeks after acetaminophen exposure. Whole exome sequencing revealed compound heterozygous variants c.512_514delCCT (p.Ser171del) and c.931G > T (p.Gly311Trp) in TALDO1 (HGNC:11559), which encodes transaldolase (EC 2.2.1.2), a key enzyme in ribose metabolism. Urine polyols and plasma metabolomics confirmed the diagnosis of transaldolase deficiency. Studies on the Taldo1 ^-/- mouse model demonstrate acetaminophen-induced liver failure can be prevented by administration of the antioxidant N-acetylcysteine. Moreover, a published report showed treatment of a transaldolase-deficient patient with N-acetylcysteine was associated with a decrease in alpha-fetoprotein levels. After discontinuation of acetaminophen and prior to initiation of N-acetylcysteine treatment, our patient demonstrated resolving alpha-fetoprotein levels suggesting acetaminophen incited the liver failure. Conclusion: Our observations support the conclusion from mouse model studies that transaldolase-deficient patients are uniquely sensitive to acetaminophen and should avoid this antipyretic. Recognition of this individualized toxicity and avoidance of acetaminophen are essential for management of these patients.

Selective Constraints on Coding Sequences of Nervous System Genes Are a Major Determinant of Duplicate Gene Retention in Vertebrates

The evolutionary history of vertebrates is marked by three ancient whole-genome duplications: two successive rounds in the ancestor of vertebrates, and a third one specific to teleost fishes. Biased loss of most duplicates enriched the genome for specific genes, such as slow evolving genes, but this selective retention process is not well understood. To understand what drives the long-term preservation of duplicate genes, we characterized duplicated genes in terms of their expression patterns. We used a new method of expression enrichment analysis, TopAnat, applied to in situ hybridization data from thousands of genes from zebrafish and mouse. We showed that the presence of expression in the nervous system is a good predictor of a higher rate of retention of duplicate genes after whole-genome duplication. Further analyses suggest that purifying selection against the toxic effects of misfolded or misinteracting proteins, which is particularly strong in nonrenewing neural tissues, likely constrains the evolution of coding sequences of nervous system genes, leading indirectly to the preservation of duplicate genes after whole-genome duplication. Whole-genome duplications thus greatly contributed to the expansion of the toolkit of genes available for the evolution of profound novelties of the nervous system at the base of the vertebrate radiation.

Identification of differentially expressed genes in the development of osteosarcoma using RNA-seq

Objective

Osteosarcoma (OS) is a malignant bone tumor with high morbidity in young adults and adolescents. This study aimed to discover potential early diagnosis biomarkers in OS.

Results

In total, 111 differentially expressed genes (DEGs) were identified in primary OS compared with normal controls and 235 DEGs were identified in metastatic OS compared with primary OS. AURKB and PPP2R2B were the significantly up-regulated and down-regulated hub proteins, respectively, in the PPI protein-protein network (PPI) network of primary OS. ISG15 and BTRC were the significantly up-regulated and down-regulated hub proteins, respectively, in the network of metastatic OS. The DEGs in metastatic OS compared with primary OS were significantly enriched in the arachidonic acid metabolism, malaria, and chemokine signaling pathways. Finally, we employed quantitative real-time polymerase chain reaction (qRT-PCR) to validate the expression levels of candidate DEGs and the results indicated that our bioinformatics approach was acceptable.

Materials and Methods

The mRNA expression profiling of 20 subjects was obtained through high-throughput RNA-sequencing. DEGs were identified between primary OS and normal Control, and between primary OS and metastatic OS, respectively. Functional annotation and PPI networks were used to obtain insights into the functions of DEGs. qRT-PCR was performed to detect the expression levels of dysregulated genes in OS.

Conclusions

Our work might provide groundwork for the further exploration of tumorigenesis and metastasis mechanisms of OS.

Deep Cap Analysis of Gene Expression (CAGE): Genome-Wide Identification of Promoters, Quantification of Their Activity, and Transcriptional Network Inference

Among the most significant findings of the post-genomic era, the discovery of pervasive transcription of mammalian genomes has tremendously modified our understanding of the genome output seen as RNA molecules. The increased focus on non-protein-coding genomic regions together with concomitant technological innovations has led to rapid discovery of numerous noncoding transcripts (ncRNAs). Biological relevance and functional roles of the vast majority of these ncRNAs remain largely unknown.The cap analysis of gene expression (CAGE) technology allows accurate transcript detection and quantification without relying on preexisting transcript models. In combination with complementary data sets, generated using other technologies, it has been shown as an efficient approach for exploring transcriptome complexity.Here, we describe the use of CAGE for the identification of novel noncoding transcripts in mammalian cells providing detailed information for basic data processing and advanced bioinformatics analyses.

Evolution of Eukaryal and Archaeal Pseudouridine Synthase Pus10

In archaea, pseudouridine (Ψ) synthase Pus10 modifies uridine (U) to Ψ at positions 54 and 55 of tRNA. In contrast, Pus10 is not found in bacteria, where modifications at those two positions are carried out by TrmA (U54 to m⁵U54) and TruB (U55 to Ψ55). Many eukaryotes have an apparent redundancy; their genomes contain orthologs of archaeal Pus10 and bacterial TrmA and TruB. Although eukaryal Pus10 genes share a conserved catalytic domain with archaeal Pus10 genes, their biological roles are not clear for the two reasons. First, experimental evidence suggests that human Pus10 participates in apoptosis induced by the tumor necrosis factor-related apoptosis-inducing ligand. Whether the function of human Pus10 is in place or in addition to of Ψ synthesis in tRNA is unknown. Second, Pus10 is found in earlier evolutionary branches of fungi (such as chytrid Batrachochytrium) but is absent in all dikaryon fungi surveyed (Ascomycetes and Basidiomycetes). We did a comprehensive analysis of sequenced genomes and found that orthologs of Pus10, TrmA, and TruB were present in all the animals, plants, and protozoa surveyed. This indicates that the common eukaryotic ancestor possesses all the three genes. Next, we examined 116 archaeal and eukaryotic Pus10 protein sequences to find that Pus10 existed as a single copy gene in all the surveyed genomes despite ancestral whole genome duplications had occurred. This indicates a possible deleterious gene dosage effect. Our results suggest that functional redundancy result in gene loss or neofunctionalization in different evolutionary lineages.

Standard Codon Substitution Models Overestimate Purifying Selection for Nonstationary Data

Estimation of natural selection on protein-coding sequences is a key comparative genomics approach for de novo prediction of lineage-specific adaptations. Selective pressure is measured on a per-gene basis by comparing the rate of nonsynonymous substitutions to the rate of synonymous substitutions. All published codon substitution models have been time-reversible and thus assume that sequence composition does not change over time. We previously demonstrated that if time-reversible DNA substitution models are applied in the presence of changing sequence composition, the number of substitutions is systematically biased towards overestimation. We extend these findings to the case of codon substitution models and further demonstrate that the ratio of nonsynonymous to synonymous rates of substitution tends to be underestimated over three data sets of mammals, vertebrates, and insects. Our basis for comparison is a nonstationary codon substitution model that allows sequence composition to change. Goodness-of-fit results demonstrate that our new model tends to fit the data better. Direct measurement of nonstationarity shows that bias in estimates of natural selection and genetic distance increases with the degree of violation of the stationarity assumption. Additionally, inferences drawn under time-reversible models are systematically affected by compositional divergence. As genomic sequences accumulate at an accelerating rate, the importance of accurate de novo estimation of natural selection increases. Our results establish that our new model provides a more robust perspective on this fundamental quantity.

Identification of STAC3 variants in non-Native American families with overlapping features of Carey-Fineman-Ziter syndrome and Moebius syndrome

Horstick et al. (2013) previously reported a homozygous p.Trp284Ser variant in STAC3 as the cause of Native American myopathy (NAM) in 5 Lumbee Native American families with congenital hypotonia and weakness, cleft palate, short stature, ptosis, kyphoscoliosis, talipes deformities, and susceptibility to malignant hyperthermia (MH). Here we present two non-Native American families, who were found to have STAC3 pathogenic variants. The first proband and her affected older sister are from a consanguineous Qatari family with a suspected clinical diagnosis of Carey-Fineman-Ziter syndrome (CFZS) based on features of hypotonia, myopathic facies with generalized weakness, ptosis, normal extraocular movements, cleft palate, growth delay, and kyphoscoliosis. We identified the homozygous c.851G>C;p.Trp284Ser variant in STAC3 in both sisters. The second proband and his affected sister are from a non-consanguineous, Puerto Rican family who was evaluated for a possible diagnosis of Moebius syndrome (MBS). His features included facial and generalized weakness, minimal limitation of horizontal gaze, cleft palate, and hypotonia, and he has a history of MH. The siblings were identified to be compound heterozygous for STAC3 variants c.851G>C;p.Trp284Ser and c.763_766delCTCT;p.Leu255IlefsX58. Given the phenotypic overlap of individuals with CFZS, MBS, and NAM, we screened STAC3 in 12 individuals diagnosed with CFZS and in 50 individuals diagnosed with MBS or a congenital facial weakness disorder. We did not identify any rare coding variants in STAC3. NAM should be considered in patients presenting with facial and generalized weakness, normal or mildly abnormal extraocular movement, hypotonia, cleft palate, and scoliosis, particularly if there is a history of MH.

Germline INDELs and CNVs in a cohort of colorectal cancer patients: their characteristics, associations with relapse-free survival time, and potential time-varying effects on the risk of relapse

INDELs and CNVs are structural variations that may play roles in cancer susceptibility and patient outcomes. Our objectives were a) to computationally detect and examine the genome‐wide INDEL/CNV profiles in a cohort of colorectal cancer patients, and b) to examine the associations of frequent INDELs/CNVs with relapse‐free survival time. We also identified unique variants in 13 Familial Colorectal Cancer Type X (FCCX) cases. The study cohort consisted of 495 colorectal cancer patients. QuantiSNP and PennCNV algorithms were utilized to predict the INDELs/CNVs using genome‐wide signal intensity data. Duplex PCR was used to validate predictions for 10 variants. Multivariable Cox regression models were used to test the associations of 106 common variants with relapse‐free survival time. Score test and the multivariable Cox proportional hazards models with time‐varying coefficients were applied to identify the variants with time‐varying effects on the relapse‐free survival time. A total of 3486 distinct INDELs/CNVs were identified in the patient cohort. The majority of these variants were rare (83%) and deletion variants (81%). The results of the computational predictions and duplex PCR results were highly concordant (93–100%). We identified four promising variants significantly associated with relapse‐free survival time (P < 0.05) in the multivariable Cox proportional hazards regression models after adjustment for clinical factors. More importantly, two additional variants were identified to have time‐varying effects on the risk of relapse. Finally, 58 rare variants were identified unique to the FCCX cases; none of them were detected in more than one patient. This is one of the first genome‐wide analyses that identified the germline INDEL/CNV profiles in colorectal cancer patients. Our analyses identified novel variants and genes that can biologically affect the risk of relapse in colorectal cancer patients. Additionally, for the first time, we identified germline variants that can potentially be early‐relapse markers in colorectal cancer.

Correspondence of D. melanogaster and C. elegans developmental stages revealed by alternative splicing characteristics of conserved exons

Background

We report a statistical study to find correspondence of D. melanogaster and C. elegans developmental stages based on alternative splicing (AS) characteristics of conserved cassette exons using modENCODE RNA-seq data. We identify “stage-associated exons” to capture the AS characteristics of each stage and use these exons to map pairwise stages within and between the two species by an overlap test.

Results

Within fly and worm, adjacent developmental stages are mapped to each other, i.e., a strong diagonal pattern is observed as expected, supporting the validity of our approach. Between fly and worm, two parallel mapping patterns are observed between fly early embryos to early larvae and worm life cycle, and between fly late larvae to adults and worm late embryos to adults. We also apply this approach to compare tissues and cells from fly and worm. Findings include the high similarity between fly/worm adults and fly/worm embryos, groupings of fly cell lines, and strong mappings of fly head tissues to worm late embryos and male adults. Gene ontology and KEGG enrichment analyses provide a detailed functional annotation of the identified stage-associated exons, as well as a functional explanation of the observed correspondence map between fly and worm developmental stages.

Conclusions

Our results suggest that AS dynamics of the exon pairs that share similar DNA sequences are informative for finding transcriptomic similarity of biological samples. Our study is innovative in two aspects. First, to our knowledge, our study is the first comprehensive study of AS events in fly and worm developmental stages, tissues, and cells. AS events provide an alternative perspective of transcriptome dynamics, compared to gene expression events. Second, our results do not entirely rely on the information of orthologous genes. Interesting results are also observed for fly and worm cassette exon pairs with DNA sequence similarity but not in orthologous gene pairs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3600-2) contains supplementary material, which is available to authorized users.

Plasmid Replicons from Pseudomonas Are Natural Chimeras of Functional, Exchangeable Modules

Plasmids are a main factor for the evolution of bacteria through horizontal gene exchange, including the dissemination of pathogenicity genes, resistance to antibiotics and degradation of pollutants. Their capacity to duplicate is dependent on their replication determinants (replicon), which also define their bacterial host range and the inability to coexist with related replicons. We characterize a second replicon from the virulence plasmid pPsv48C, from Pseudomonas syringae pv. savastanoi, which appears to be a natural chimera between the gene encoding a newly described replication protein and a putative replication control region present in the widespread family of PFP virulence plasmids. We present extensive evidence of this type of chimerism in structurally similar replicons from species of Pseudomonas, including environmental bacteria as well as plant, animal and human pathogens. We establish that these replicons consist of two functional modules corresponding to putative control (REx-C module) and replication (REx-R module) regions. These modules are functionally separable, do not show specificity for each other, and are dynamically exchanged among replicons of four distinct plasmid families. Only the REx-C module displays strong incompatibility, which is overcome by a few nucleotide changes clustered in a stem-and-loop structure of a putative antisense RNA. Additionally, a REx-C module from pPsv48C conferred replication ability to a non-replicative chromosomal DNA region containing features associated to replicons. Thus, the organization of plasmid replicons as independent and exchangeable functional modules is likely facilitating rapid replicon evolution, fostering their diversification and survival, besides allowing the potential co-option of appropriate genes into novel replicons and the artificial construction of new replicon specificities.

Permanganate/S1 Nuclease Footprinting Reveals Non-B DNA Structures with Regulatory Potential across a Mammalian Genome

DNA in cells is predominantly B-form double helix. Though certain DNA sequences in vitro may fold into other structures, such as triplex, left-handed Z form, or quadruplex DNA, the stability and prevalence of these structures in vivo are not known. Here, using computational analysis of sequence motifs, RNA polymerase II binding data, and genome-wide potassium permanganate-dependent nuclease footprinting data, we map thousands of putative non-B DNA sites at high resolution in mouse B cells. Computational analysis associates these non-B DNAs with particular structures and indicates that they form at locations compatible with an involvement in gene regulation. Further analyses support the notion that non-B DNA structure formation influences the occupancy and positioning of nucleosomes in chromatin. These results suggest that non-B DNAs contribute to the control of a variety of critical cellular and organismal processes.

GLY67ARG substitution in RSPO4 disrupts the WNT signaling pathway due to an abnormal binding pattern with LGRs leading to anonychia

R-Spondins regulate the WNT/β-catenin signaling pathway by interacting with leucine rich-repeat containing G-protein coupled receptors (LGR4–6).

Visualizing Genomic Annotations with the UCSC Genome Browser

Genomic data and annotations are rapidly accumulating in databases such as the UCSC Genome Browser, NCBI, and Ensembl. Given the massive scale of these genomic databases, it is important to be able to easily retrieve known data and annotations of a specified genomic locus. For example, for a newly identified cis-regulatory element bound by a transcription factor, questions that immediately come to mind include whether the element is near a transcriptional start site and, if so, the name of the corresponding gene, and whether the histones or DNA at the locus are modified. The UCSC Genome Browser organizes data and annotations (called tracks) around the reference sequences or draft assemblies of many eukaryotic genomes and presents them using a powerful web-based graphical interface. This protocol describes how to use the UCSC Genome Browser to visualize selected tracks at specified genomic regions, download the data and annotations for further analysis, and retrieve multiple sequence alignments and their conservation scores.

Intron Length Coevolution across Mammalian Genomes

Although they do not contribute directly to the proteome, introns frequently contain regulatory elements and can extend the protein coding potential of the genome through alternative splicing. For some genes, the contribution of introns to the time required for transcription can also be functionally significant. We have previously shown that intron length in genes associated with developmental patterning is often highly conserved. In general, sets of genes that require precise coordination in the timing of their expression may be sensitive to changes in transcript length. A prediction of this hypothesis is that evolutionary changes in intron length, when they occur, may be correlated between sets of coordinately expressed genes. To test this hypothesis, we analyzed intron length coevolution in alignments from nine eutherian mammals. Overall, genes that belong to the same protein complex or that are coexpressed were significantly more likely to show evidence of intron length coevolution than matched, randomly sampled genes. Individually, protein complexes involved in the cell cycle showed the strongest evidence of coevolution of intron lengths and clusters of coexpressed genes enriched for cell cycle genes also showed significant evidence of intron length coevolution. Our results reveal a novel aspect of gene coevolution and provide a means to identify genes, protein complexes and biological processes that may be particularly sensitive to changes in transcriptional dynamics.

An optimised phylogenetic method sheds more light on the main branching events of rhodopsin-like superfamily

The comparative genomics between different rhodopsin-like family groups (α, β, γ and δ) is not well studied. We used a combination of phylogenetic analysis and statistical genomic methods to compare rhodopsin-like family proteins in species likely symbolic of this family's evolutionary progression. For intra-cluster relationships, we applied mathematical optimisation to enhance the tree search produced by the neighbour joining method (NJ) and compared it with maximum likelihood (ML) method. To infer inter-clusters relationships, we used Needleman-Wunsch analysis (NW), HHsearch, ancestral sequence reconstruction and phylogenetic network analysis. Using this workflow, we were able to identify key evolutionary events in the rhodopsin-like family receptors. We found that α rhodopsin-like group gave rise to the β group, while the γ rhodopsin-like group diverged from the β group. We tracked the diversification of every cluster, revealing that fungal opsin is the most ancient member of the α group, while adenosine receptors could be the first member to diverge in the MECA (melanocortin, endothelial differentiation sphingolipid, cannabinoid, and adenosine receptors) subfamily and that histamine receptors could be the parent of the amines receptors, while hypocretin receptors might be the most ancient member of the β group. SOG (somatostatin, opioid, galanin) receptors formed the most ancient members of the γ group. Our analysis indicated that basal receptors might be playing a role in early evolution of the nervous system. This is evident in Trichoplax adhaerens genome, where we located histamine receptors and adenosine receptors.

Data on the evolutionary history of the V(D)J recombination-activating protein 1 - RAG1 coupled with sequence and variant analyses

RAG1 protein is one of the key component of RAG complex regulating the V(D)J recombination. There are only few studies for RAG1 concerning evolutionary history, detailed sequence and mutational hotspots. Herein, we present out datasets used for the recent comprehensive study of RAG1 based on sequence, phylogenetic and genetic variant analyses (Kumar et al., 2015) [1]. Protein sequence alignment helped in characterizing the conserved domains and regions of RAG1. It also aided in unraveling ancestral RAG1 in the sea urchin. Human genetic variant analyses revealed 751 mutational hotspots, located both in the coding and the non-coding regions. For further analysis and discussion, see (Kumar et al., 2015) [1].

A method for identifying discriminative isoform-specific peptides for clinical proteomics application

Background

Clinical proteomics application aims at solving a specific clinical problem within the context of a clinical study. It has been growing rapidly in the field of biomarker discovery, especially in the area of cancer diagnostics. Until recently, protein isoform has not been viewed as a new class of early diagnostic biomarkers for clinical proteomics. A protein isoform is one of different forms of the same protein. Different forms of a protein may be produced from single-nucleotide polymorphisms (SNPs), alternative splicing, or post-translational modifications (PTMs). Previous studies have shown that protein isoforms play critical roles in tumorigenesis, disease diagnosis, and prognosis. Identifying and characterizing protein isoforms are essential to the study of molecular mechanisms and early detection of complex diseases such as breast cancer.

However, there are limitations with traditional methods such as EST sequencing, Microarray profiling (exon array, Exon-exon junction array), mRNA next-generation sequencing used for protein isoform determination: 1) not in the protein level, 2) no connectivity about connection of nonadjacent exons, 3) no SNPs and PTMs, and 4) low reproducibility. Moreover, there exist the computational challenges of clinical proteomics studies: 1) low sensitivity of instruments, 2) high data noise, and 3) high variability and low repeatability, although recent advances in clinical proteomics technology, LC-MS/MS proteomics, have been used to identify candidate molecular biomarkers in diverse range of samples, including cells, tissues, serum/plasma, and other types of body fluids.

Results

Therefore, in the paper, we presented a peptidomics method for identifying cancer-related and isoform-specific peptide for clinical proteomics application from LC-MS/MS. First, we built a Peptidomic Database of Human Protein Isoforms, then created a peptidomics approach to perform large-scale screen of breast cancer-associated alternative splicing isoform markers in clinical proteomics, and lastly performed four kinds of validations: biological validation (explainable index), exon array, statistical validation of independent samples, and extensive pathway analysis.

Conclusions

Our results showed that alternative splicing isoform makers can act as independent markers of breast cancer and that the method for identifying cancer-specific protein isoform biomarkers from clinical proteomics application is an effective one for increasing the number of identified alternative splicing isoform markers in clinical proteomics.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2907-8) contains supplementary material, which is available to authorized users.