title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1344 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Coastal fish assemblages and predation pressure in northern-central Chilean Lessonia trabeculata kelp forests and barren grounds link: https://peerj.com/articles/6964 last-modified: 2019-06-12 description: Kelp forests are declining in many parts of the globe, which can lead to the spreading of barren grounds. Increased abundances of grazers, mainly due to reduction of their predators, are among the causes of this development. Here, we compared the species richness (SR), frequency of occurrence (FO), and maximum abundance (MaxN) of predatory fish and their predation pressure between kelp forest and barren ground habitats of northern-central Chile. Sampling was done using baited underwater cameras with vertical and horizontal orientation. Two prey organisms were used as tethered baits, the black sea urchin Tetrapygus niger and the porcelanid crab Petrolisthes laevigatus. SR did not show major differences between habitats, while FO and MaxN were higher on barren grounds in vertical videos, with no major differences between habitats in horizontal videos. Predation pressure did not differ between habitats, but after 24 h consumption of porcelanid crabs was significantly higher than that of sea urchins. Scartichthys viridis/gigas was the main predator, accounting for 82% of the observed predation events on Petrolisthes laevigatus. Most of these attacks occurred on barren grounds. Scartichthys viridis/gigas was the only fish observed attacking (but not consuming) tethered sea urchins. High abundances of opportunistic predators (Scartichthys viridis/gigas) are probably related to low abundances of large predatory fishes. These results suggest that intense fishing activity on large predators, and their resulting low abundances, could result in low predation pressure on sea urchins, thereby contributing to the increase of T. niger abundances in subtidal rocky habitats. creator: Nicolás Riquelme-Pérez creator: Catalina A. Musrri creator: Wolfgang B. Stotz creator: Osvaldo Cerda creator: Oscar Pino-Olivares creator: Martin Thiel uri: https://doi.org/10.7717/peerj.6964 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Riquelme-Pérez et al. title: Relative and absolute within-session reliability of the modified Star Excursion Balance Test in healthy elite athletes link: https://peerj.com/articles/6999 last-modified: 2019-06-12 description: BackgroundThe Star Excursion Balance Test (SEBT) is commonly used to assess dynamic postural balance both in clinical practice and research. The aim of our study was to assess the within-session relative and absolute reliability of participants’ performance of the modified SEBT (mSEBT) using a single practice trial in healthy elite athletes who were familiar with the test.MethodsAn intra-session repeated-measures design was used to investigate the relative and absolute reliability of participants’ (healthy athletes partaking in sports at a high-risk of ankle sprain injury) performance of the mSEBT. A total of 122 healthy elite athletes from soccer (n = 73), basketball (n = 15), and volleyball (n = 34) performed one practice trial and three test trials within one session, in three directions (anterior, postero-medial, and postero-lateral), for both legs. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest detectable change at a 95% confidence were calculated.ResultsWe found a good to excellent relative within-session intra-rater reliability between the three trials on specified directions, with an ICC (3,1) from 0.90 to 0.95. SEM and SDC95 for normalized and composite scores, for both legs ranged from 0.91 to 2.86, and 2.54 to 7.94, respectively.ConclusionsIn conclusion, we report good to excellent within-session reliability for the mSEBT. Our results confirm that the test can be reliably used with only one practice trial in healthy elite athletes familiar with the test. creator: Roxana R. Onofrei creator: Elena Amaricai creator: Radu Petroman creator: Oana Suciu uri: https://doi.org/10.7717/peerj.6999 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Onofrei et al. title: Fine-root traits of allelopathic rice at the seedling stage and their relationship with allelopathic potential link: https://peerj.com/articles/7006 last-modified: 2019-06-12 description: BackgroundAllelopathic rice releases allelochemicals through its root systems, thereby exerting a negative effect on paddy weeds. This research aimed to evaluate the relationship between fine-root traits and the rice allelopathic potential at the seedling stage.MethodsTwo allelopathic rice cultivars, ‘PI312777’ and ‘Taichung Native1,’ and one non-allelopathic rice cultivar, ‘Lemont,’ were grown to the 3–6 leaf stage in a hydroponic system. Their fine roots were collected for morphological trait (root length, root surface area, root volume, and root tips number) in smaller diameter cutoffs and proliferative trait (root biomass) analysis. Their root-exudates were used for quantitative analysis of phenolic acids contents and an evaluation of allelopathic potential. Correlation analysis was also used to assess whether any linear relationships existed.ResultsOur results showed that allelopathic rice cultivars had significantly higher fine-root length having diameters <0.2 mm, more root tips number, and greater root biomass, coupled with higher allelopathic potential and phenolic acid contents of their root exudates, comparing with non-allelopathic rice cultivar. These fine-root traits were significantly-positively correlated to allelopathic inhibition and total phenolic contents in rice root-exudates. However, there were not significant correlations among the rice allelopathic potential and total phenolic acid contents of rice root-exudates with the root length, root surface area, and root volume of fine root in diameter >0.2 mm.DiscussionOur results implied that fine-root traits appears to be important in understanding rice allelopathy at the seedling stage. The high allelopathic potential of rice cultivars might be attributed to their higher length of fine roots <0.2 mm in diameter and more number of root tips of fine root, which could accumulate and release more allelochemicals to solutions, thereby resulting in high inhibition on target plants. The mechanisms regulating this process need to be further studied. creator: Jiayu Li creator: Shunxian Lin creator: Qingxu Zhang creator: Qi Zhang creator: Wenwen Hu creator: Haibin He uri: https://doi.org/10.7717/peerj.7006 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Li et al. title: Water regime and osmotic adjustment under warming conditions on wheat in the Yaqui Valley, Mexico link: https://peerj.com/articles/7029 last-modified: 2019-06-12 description: An experiment was carried out to evaluate the effect of increased temperature on roots and leaf water and osmotic potential, osmotic adjustment (OA) and transpiration on Triticum durum L. (CIRNO C2008 variety) during growth (seedling growth), tillering and heading phenophases. Wheat was sown under field conditions at the Experimental Technology Transfer Center (CETT-910), as a representative wheat crop area from the Yaqui Valley, Sonora México. Thermal radiators were placed at 1.20 m from the crop canopy. Treatments included warmed plots (2 °C) and ambient canopy temperature with five replicates. Temperature treatment was controlled using a (proportional, integrative, derivative) feedback control system on plots covering a circular area of r = 1.5 m. Results indicated a significant decrease in the osmotic potential of roots and leaves for the warmed plots. Water potential, under warming treatment, also experienced a significant reduction and a potential gradient was observed in both, roots and leaves, while the phenophases were delayed. Such results demonstrate that, under warmer conditions, plants increase water absorption for cooling. Hence, transpiration experienced a significant increase under warming in all phenophases that was related to the low root and leaf water potential. CIRNO C2008 also experienced OA in all phenophases with glycine betaine as the osmolyte with major contribution. creator: Leandris Argentel-Martínez creator: Jaime Garatuza-Payan creator: Enrico A. Yepez creator: Tulio Arredondo creator: Sergio de los Santos-Villalobos uri: https://doi.org/10.7717/peerj.7029 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Argentel-Martínez et al. title: Identification and characterization of PsDREB2 promoter involved in tissue-specific expression and abiotic stress response from Paeonia suffruticosa link: https://peerj.com/articles/7052 last-modified: 2019-06-12 description: Dehydration-responsive element-binding factor 2 (DREB2) belongs to the C-repeat-binding factor (CBF)/DREB subfamily of proteins. In this study, a 2,245 bp PsDREB2 promoter fragment was isolated from the genome of Paeonia suffruticosa. The fragment was rich in A/T bases and contained TATA box sequences, abscisic acid (ABA)-response elements, and other cis-elements, such as MYB and CAAT box. The promoter was fused with the β-glucuronidase (GUS) reporter gene to generate an expression vector. Arabidopsis thaliana was transformed with a flower dipping method. Gus activity in different tissues and organs of transgenic plants was determined via histochemical staining and quantified via GUS fluorescence. The activity of promoter regulatory elements in transgenic plants under drought, low-temperature, high-salt, and ABA stresses was analyzed. The results showed that the PsDREB2 gene promoter was expressed in the roots, stems, leaves, flowers, and silique pods but not in the seeds of transgenic Arabidopsis. Furthermore, the promoter was induced by drought, low temperature, high salt, and ABA. Hence, the PsDREB2 promoter is tissue- and stress-specific and can be used in the genetic engineering of novel peony cultivars in the future. creator: Huichun Liu creator: Kaiyuan Zhu creator: Chen Tan creator: Jiaqiang Zhang creator: Jianghua Zhou creator: Liang Jin creator: Guangying Ma creator: Qingcheng Zou uri: https://doi.org/10.7717/peerj.7052 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Liu et al. title: Sex- and tissue-specific expression of odorant-binding proteins and chemosensory proteins in adults of the scarab beetle Hylamorpha elegans (Burmeister) (Coleoptera: Scarabaeidae) link: https://peerj.com/articles/7054 last-modified: 2019-06-12 description: In this study, we addressed the sex- and tissue-specific expression patterns of odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) in Hylamorpha elegans (Burmeister), an important native scarab beetle pest species from Chile. Similar to other members of its family, this scarab beetle exhibit habits that make difficult to control the pest by conventional methods. Hence, alternative ways to manage the pest populations based on chemical communication and signaling (such as disrupting mating or host finding process) are highly desirable. However, developing pest-control methods based on chemical communication requires to understand the molecular basis for pheromone recognition/chemical perception in this species. Thus, with the aim of discovering olfaction-related genes, we obtained the first reference transcriptome assembly of H. elegans. We used different tissues of adult beetles from males and females: antennae and maxillary palps, which are well known for embedded sensory organs. Then, the expression of predicted odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) was analyzed by qRT-PCR. In total, 165 transcripts related to chemoperception were predicted. Of these, 16 OBPs, including one pheromone-binding protein (PBP), and four CSPs were successfully amplified by qRT-PCR. All of these genes were differentially expressed in the sensory tissues with respect to the tibial tissue that was used as a control. The single predicted PBP found was highly expressed in the antennal tissues, particularly in males, while several OBPs and one CSP showed male-biased expression patterns, suggesting that these proteins may participate in sexual recognition process. In addition, a single CSP was expressed at higher levels in female palps than in any other studied condition, suggesting that this CSP would participate in oviposition process. Finally, all four CSPs exhibited palp-biased expression while mixed results were obtained for the expression of the OBPs, which were more abundant in the palps than in the antennae. These results suggest that these chemoperception proteins would be interesting novel targets for control of H. elegans, thus providing a theoretical basis for further studies involving new pest control methods. creator: Angélica González-González creator: María E. Rubio-Meléndez creator: Gabriel I. Ballesteros creator: Claudio C. Ramírez creator: Rubén Palma-Millanao uri: https://doi.org/10.7717/peerj.7054 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 González-González et al. title: Bioinformatic pipelines for whole transcriptome sequencing data exploitation in leukemia patients with complex structural variants link: https://peerj.com/articles/7071 last-modified: 2019-06-12 description: BackgroundExtensive genome rearrangements, known as chromothripsis, have been recently identified in several cancer types. Chromothripsis leads to complex structural variants (cSVs) causing aberrant gene expression and the formation of de novo fusion genes, which can trigger cancer development, or worsen its clinical course. The functional impact of cSVs can be studied at the RNA level using whole transcriptome sequencing (total RNA-Seq). It represents a powerful tool for discovering, profiling, and quantifying changes of gene expression in the overall genomic context. However, bioinformatic analysis of transcriptomic data, especially in cases with cSVs, is a complex and challenging task, and the development of proper bioinformatic tools for transcriptome studies is necessary.MethodsWe designed a bioinformatic workflow for the analysis of total RNA-Seq data consisting of two separate parts (pipelines): The first pipeline incorporates a statistical solution for differential gene expression analysis in a biologically heterogeneous sample set. We utilized results from transcriptomic arrays which were carried out in parallel to increase the precision of the analysis. The second pipeline is used for the identification of de novo fusion genes. Special attention was given to the filtering of false positives (FPs), which was achieved through consensus fusion calling with several fusion gene callers. We applied the workflow to the data obtained from ten patients with chronic lymphocytic leukemia (CLL) to describe the consequences of their cSVs in detail. The fusion genes identified by our pipeline were correlated with genomic break-points detected by genomic arrays.ResultsWe set up a novel solution for differential gene expression analysis of individual samples and de novo fusion gene detection from total RNA-Seq data. The results of the differential gene expression analysis were concordant with results obtained by transcriptomic arrays, which demonstrates the analytical capabilities of our method. We also showed that the consensus fusion gene detection approach was able to identify true positives (TPs) efficiently. Detected coordinates of fusion gene junctions were in concordance with genomic breakpoints assessed using genomic arrays.DiscussionByapplying our methods to real clinical samples, we proved that our approach for total RNA-Seq data analysis generates results consistent with other genomic analytical techniques. The data obtained by our analyses provided clues for the study of the biological consequences of cSVs with far-reaching implications for clinical outcome and management of cancer patients. The bioinformatic workflow is also widely applicable for addressing other research questions in different contexts, for which transcriptomic data are generated. creator: Jakub Hynst creator: Karla Plevova creator: Lenka Radova creator: Vojtech Bystry creator: Karol Pal creator: Sarka Pospisilova uri: https://doi.org/10.7717/peerj.7071 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Hynst et al. title: Estimating biological accuracy of DSM for attention deficit/hyperactivity disorder based on multivariate analysis for small samples link: https://peerj.com/articles/7074 last-modified: 2019-06-12 description: ObjectiveTo estimate whether the “Diagnostic and Statistical Manual of Mental Disorders” (DSM) is biologically accurate for the diagnosis of Attention Deficit/ Hyperactivity Disorder (ADHD) using a biological-based classifier built by a special method of multivariate analysis of a large dataset of a small sample (much more variables than subjects), holding neurophysiological, behavioral, and psychological variables.MethodsTwenty typically developing boys and 19 boys diagnosed with ADHD, aged 10–13 years, were examined using the Attentional Network Test (ANT) with recordings of event-related potentials (ERPs). From 774 variables, a reduced number of latent variables (LVs) were extracted with a clustering of variables method (CLV), for further reclassification of subjects using the k-means method. This approach allowed a multivariate analysis to be applied to a significantly larger number of variables than the number of cases.ResultsFrom datasets including ERPs from the mid-frontal, mid-parietal, right frontal, and central scalp areas, we found 82% of agreement between DSM and biological-based classifications. The kappa index between DSM and behavioral/psychological/neurophysiological data was 0.75, which is regarded as a “substantial level of agreement”.DiscussionThe CLV is a useful method for multivariate analysis of datasets with much less subjects than variables. In this study, a correlation is found between the biological-based classifier and the DSM outputs for the classification of subjects as either ADHD or not. This result suggests that DSM clinically describes a biological condition, supporting its validity for ADHD diagnostics. creator: Dimitri M. Abramov creator: Vladimir V. Lazarev creator: Saint Clair Gomes Junior creator: Carlos Alberto Mourao-Junior creator: Monique Castro-Pontes creator: Carla Q. Cunha creator: Leonardo C. deAzevedo creator: Evelyne Vigneau uri: https://doi.org/10.7717/peerj.7074 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Abramov et al. title: Genetic diversity of gliadin-coding alleles in bread wheat (Triticum aestivum L.) from Northern Kazakhstan link: https://peerj.com/articles/7082 last-modified: 2019-06-12 description: BackgroundSpring bread wheat (Triticum aestivum L.) represents the main cereal crop in Northern Kazakhstan. The quality of wheat grain and flour strongly depends on the structure of gluten, comprised of gliadin and glutenin proteins. Electrophoresis spectra of gliadins are not altered by environmental conditions or plant growth, are easily reproducible and very useful for wheat germplasm identification in addition to DNA markers. Genetic polymorphism of two Gli loci encoding gliadins can be used for selection of preferable genotypes of wheat with high grain quality.MethodsPolyacrylamide gel electrophoresis was used to analyse genetic diversity of gliadins in a germplasm collection of spring bread wheat from Northern Kazakhstan.ResultsThe highest frequencies of gliadin alleles were found as follows, in Gli1: -A1f (39.3%), -B1e (71.9%), and -D1a (41.0%); and in Gli-2: -A2q (17.8%), -B2t (13.5%), and -D2q (20.4%). The combination of these alleles in a single genotype may be associated with higher quality of grain as well as better adaptation to the dry environment of Northern Kazakhstan; preferable for wheat breeding in locations with similar conditions. creator: Maral Utebayev creator: Svetlana Dashkevich creator: Nina Bome creator: Kulpash Bulatova creator: Yuri Shavrukov uri: https://doi.org/10.7717/peerj.7082 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Utebayev et al. title: T cell receptor signaling pathway and cytokine-cytokine receptor interaction affect the rehabilitation process after respiratory syncytial virus infection link: https://peerj.com/articles/7089 last-modified: 2019-06-12 description: BackgroundRespiratory syncytial virus (RSV) is the main cause of respiratory tract infection, which seriously threatens the health and life of children. This study is conducted to reveal the rehabilitation mechanisms of RSV infection.MethodsE-MTAB-5195 dataset was downloaded from EBI ArrayExpress database, including 39 acute phase samples in the acute phase of infection and 21 samples in the recovery period. Using the limma package, differentially expressed RNAs (DE-RNAs) were analyzed. The significant modules were identified using WGCNA package, and the mRNAs in them were conducted with enrichment analysis using DAVID tool. Afterwards, co-expression network for the RNAs involved in the significant modules was built by Cytoscape software. Additionally, RSV-correlated pathways were searched from Comparative Toxicogenomics Database, and then the pathway network was constructed.ResultsThere were 2,489 DE-RNAs between the two groups, including 2,386 DE-mRNAs and 103 DE-lncRNAs. The RNAs in the black, salmon, blue, tan and turquoise modules correlated with stage were taken as RNA set1. Meanwhile, the RNAs in brown, blue, magenta and pink modules related to disease severity were defined as RNA set2. In the pathway networks, CD40LG and RASGRP1 co-expressed with LINC00891/LINC00526/LINC01215 were involved in the T cell receptor signaling pathway, and IL1B, IL1R2, IL18, and IL18R1 co-expressed with BAIAP2-AS1/CRNDE/LINC01503/SMIM25 were implicated in cytokine-cytokine receptor interaction.ConclusionLINC00891/LINC00526/LINC01215 co-expressed with CD40LG and RASGRP1 might affect the rehabilitation process of RSV infection through the T cell receptor signaling pathway. Besides, BAIAP2-AS1/CRNDE/LINC01503/SMIM25 co-expressed with IL1 and IL18 families might function in the clearance process after RSV infection via cytokine-cytokine receptor interaction. creator: Zuanhao Qian creator: Zhenglei Zhang creator: Yingying Wang uri: https://doi.org/10.7717/peerj.7089 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Qian et al.