50 research outputs found
Ancestry Analysis in the 11-M Madrid Bomb Attack Investigation
The 11-M Madrid commuter train bombings of 2004 constituted the second biggest terrorist attack to occur in Europe after
Lockerbie, while the subsequent investigation became the most complex and wide-ranging forensic case in Spain. Standard
short tandem repeat (STR) profiling of 600 exhibits left certain key incriminatory samples unmatched to any of the
apprehended suspects. A judicial order to perform analyses of unmatched samples to differentiate European and North
African ancestry became a critical part of the investigation and was instigated to help refine the search for further suspects.
Although mitochondrial DNA (mtDNA) and Y-chromosome markers routinely demonstrate informative geographic
differentiation, the populations compared in this analysis were known to show a proportion of shared mtDNA and Y
haplotypes as a result of recent gene-flow across the western Mediterranean, while any two loci can be unrepresentative of
the ancestry of an individual as a whole. We based our principal analysis on a validated 34plex autosomal ancestryinformative-marker single nucleotide polymorphism (AIM-SNP) assay to make an assignment of ancestry for DNA from
seven unmatched case samples including a handprint from a bag containing undetonated explosives together with
personal items recovered from various locations in Madrid associated with the suspects. To assess marker informativeness
before genotyping, we predicted the probable classification success for the 34plex assay with standard error estimators for a
naı¨ve Bayesian classifier using Moroccan and Spanish training sets (each n = 48). Once misclassification error was found to
be sufficiently low, genotyping yielded seven near-complete profiles (33 of 34 AIM-SNPs) that in four cases gave
probabilities providing a clear assignment of ancestry. One of the suspects predicted to be North African by AIM-SNP
analysis of DNA from a toothbrush was identified late in the investigation as Algerian in origin. The results achieved illustrate
the benefit of adding specialized marker sets to provide enhanced scope and power to an already highly effective system of
DNA analysis for forensic identification.European Commission GROWTH program, SNPforID project, contract G6RD-CT-2002-00844 to CP. Xunta de Galicia, Spain: Fund PGIDTIT06PXIB228195PR and Ministerio de Educación y Ciencia, Spain: project BIO2006-06178 to MVL. Fundación de Investigación Médica Mutua Madrileña, Spain: 2006/CL370 and 2008/CL444 to AS. Continued development of the work and its application to forensic analysis is being funded by Allelyus, Santiago de Compostela, SpainS
Pantograph wear assesment in overhead conductor rail systems
Wear is the phenomenon that determines the lifetime of the collector strips. Since wear is an inevitable effect on pantograph-catenary systems, it is necessary to determine optimal operating conditions that can mitigate its effects. In this study we have performed a simulation model of the pantograph-overhead conductor rail system which allows the evaluation of the dynamic conditions of the system through the contact force. With these results we have made an evaluation of the quality of current collection, a calculation of the pantograph wear and a definition of the optimal operation conditions of the pantograph-overhead conductor rail system
Application of virtual certification techniques to vehicle design and track maintenance
Virtual certification partially substitutes by computer simulations the experimental techniques required for rail vehicle certification. In this paper, several works were these techniques were used in the vehicle design and track maintenance processes are presented. Dynamic simulation of multibody systems was used to virtually apply the EN14363 standard to certify the dynamic behaviour of vehicles. The works described are: assessment of a freight bogie design adapted to meter-gauge, assessment of a railway track layout for a subway network, freight bogie design with higher speed and axle load, and processing of the data acquired by a track recording vehicle for track maintenance
Development and Validation of Single Nucleotide Polymorphisms (SNPs) Markers from Two Transcriptome 454-Runs of Turbot (Scophthalmus maximus) Using High-Throughput Genotyping
The turbot (Scophthalmus maximus) is a commercially valuable flatfish and one of the most promising aquaculture species in Europe. Two transcriptome 454-pyrosequencing runs were used in order to detect Single Nucleotide Polymorphisms (SNPs) in genes related to immune response and gonad differentiation. A total of 866 true SNPs were detected in 140 different contigs representing 262,093 bp as a whole. Only one true SNP was analyzed in each contig. One hundred and thirteen SNPs out of the 140 analyzed were feasible (genotyped), while Ш were polymorphic in a wild population. Transition/transversion ratio (1.354) was similar to that observed in other fish studies. Unbiased gene diversity (He) estimates ranged from 0.060 to 0.510 (mean = 0.351), minimum allele frequency (MAF) from 0.030 to 0.500 (mean = 0.259) and all loci were in Hardy-Weinberg equilibrium after Bonferroni correction. A large number of SNPs (49) were located in the coding region, 33 representing synonymous and 16 non-synonymous changes. Most SNP-containing genes were related to immune response and gonad differentiation processes, and could be candidates for functional changes leading to phenotypic changes. These markers will be useful for population screening to look for adaptive variation in wild and domestic turbot.This study was supported by the Consolider Ingenio Aquagenomics (CSD200700002), the Science and Education Spanish Ministry (AGL2009-11782) and the Xunta de Galicia (09MMA011261PR) projectsS
Integrative transcriptome, genome and quantitative trait loci resources identify single nucleotide polymorphisms in candidate genes for growth traits in turbot
Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotide polymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish species
New insights into the Manila clam – Perkinsus olseni interaction based on gene expression analysis of clam hemocytes and parasite trophozoites through in vitro challenges
The Manila clam (Ruditapes philippinarum) is the bivalve species with the highest global production from both fisheries and aquaculture, but its production is seriously threatened by perkinsosis, a disease caused by the protozoan parasite Perkinsus olseni. To understand the molecular mechanisms underlying R. philippinarum–P. olseni interactions, we analysed the gene expression profiles of in vitro challenged clam hemocytes and P. olseni trophozoites, using two oligo-microarray platforms, one previously validated for R. philippinarum hemocytes and a new one developed and validated in this study for P. olseni. Manila clam hemocytes were in vitro challenged with trophozoites, zoospores, and extracellular products from P. olseni in vitro cultures, while P. olseni trophozoites were in vitro challenged with Manila clam plasma along the same time-series (1 h, 8 h, and 24 h). The hemocytes showed a fast activation of the innate immune response, particularly associated with hemocyte recruitment, in the three types of challenges. Nevertheless, different immune-related pathways were activated in response to the different parasite stages, suggesting specific recognition mechanisms. Furthermore, the analyses provided useful complementary data to previous in vivo challenges, and confirmed the potential of some proposed biomarkers. The combined analysis of gene expression in host and parasite identified several processes in both the clam and P. olseni, such as redox and glucose metabolism, protease activity, apoptosis and iron metabolism, whose modulation suggests cross-talk between parasite and host. This information might be critical to determine the outcome of the infection, thus highlighting potential therapeutic targets. Altogether, the results of this study aid understanding the response and interaction between R. philippinarum and P. olseni, and will contribute to developing effective control strategies for this threatening parasitosisThis work was funded by the Ministerio de Economía y Competitividad of the Spanish Government, through the projects (AGL2011-30449-C02-01 and AGL2012-37981), the European Regional Development Funds (FEDER 2007–2013) and the Regional Government of Galicia, Xunta de Galicia, Spain, through the projects ED431C 2018/28 and ED431D 2017/21. The study was also supported by the Centro de Supercomputación de Galicia (CESGA). The first author would like to acknowledge the PhD scholarship awarded by the EXPERTS III Consortium of the European Community Mobility Programme “Erasmus Mundus Action 2, Strand 1” (EMA2). SFB was supported by a scholarship of the Consellería do Mar da Xunta de GaliciaS
Blood Transcriptomics of Turbot Scophthalmus maximus:A Tool for Health Monitoring and Disease Studies
Blood transcriptomics is emerging as a relevant tool to monitor the status of the immune system and assist in diagnosis, prognosis, treatment and pathogenesis studies of diseases. In fish pathology, the potential of transcriptome profiling of blood is still poorly explored. Here, RNA sequencing was applied to analyze the blood transcriptional profile of turbot (Scophthalmus maximus), the most important farmed flatfish. The study was conducted in healthy specimens and specimens parasitized by the myxozoan Enteromyxum scophthalmi, which causes one of the most devastating diseases in turbot aquaculture. The blood of healthy turbot showed a transcriptomic profile mainly related to erythrocyte gas transportation function, but also to antigen processing and presentation. In moderately infected turbot, the blood reflected a broad inhibition of the immune response. Particularly, down-regulation of the B cell receptor signaling pathway was shared with heavily parasitized fish, which showed larger transcriptomic changes, including the activation of the inflammatory response. Turbot response to enteromyxosis proved to be delayed, dysregulated and ineffective in stopping the infection. The study evinces that blood transcriptomics can contribute to a better understanding of the teleost immune system and serve as a reliable tool to investigate the physiopathological status of fish
A combined strategy involving Sanger and 454 pyrosequencing increases genomic resources to aid in the management of reproduction, disease control and genetic selection in the turbot (Scophthalmus maximus)
Background: Genomic resources for plant and animal species that are under exploitation primarily for human
consumption are increasingly important, among other things, for understanding physiological processes and for
establishing adequate genetic selection programs. Current available techniques for high-throughput sequencing
have been implemented in a number of species, including fish, to obtain a proper description of the transcriptome.
The objective of this study was to generate a comprehensive transcriptomic database in turbot, a highly priced
farmed fish species in Europe, with potential expansion to other areas of the world, for which there are unsolved
production bottlenecks, to understand better reproductive- and immune-related functions. This information is
essential to implement marker assisted selection programs useful for the turbot industry.
Results: Expressed sequence tags were generated by Sanger sequencing of cDNA libraries from different immunerelated tissues after several parasitic challenges. The resulting database (“Turbot 2 database”) was enlarged with
sequences generated from a 454 sequencing run of brain-hypophysis-gonadal axis-derived RNA obtained from
turbot at different development stages. The assembly of Sanger and 454 sequences generated 52,427 consensus
sequences (“Turbot 3 database”), of which 23,661 were successfully annotated. A total of 1,410 sequences were
confirmed to be related to reproduction and key genes involved in sex differentiation and maturation were
identified for the first time in turbot (AR, AMH, SRY-related genes, CYP19A, ZPGs, STAR FSHR, etc.). Similarly, 2,241
sequences were related to the immune system and several novel key immune genes were identified (BCL, TRAF,
NCK, CD28 and TOLLIP, among others). The number of genes of many relevant reproduction- and immune-related
pathways present in the database was 50–90% of the total gene count of each pathway. In addition, 1,237
microsatellites and 7,362 single nucleotide polymorphisms (SNPs) were also compiled. Further, 2,976 putative
natural antisense transcripts (NATs) including microRNAs were also identified
Conclusions: The combined sequencing strategies employed here significantly increased the turbot genomic
resources available, including 34,400 novel sequences. The generated database contains a larger number of genes
relevant for reproduction- and immune-associated studies, with an excellent coverage of most genes present in
many relevant physiological pathways. This database also allowed the identification of many microsatellites and
SNP markers that will be very useful for population and genome screening and a valuable aid in marker assisted
selection programs.The current work was granted by the Spanish Government thanks to a Consolider Project (Project Aquagenomics, ref. CDS2007-0002) and to projects AGL2006-13158-C03 and
AGL2009-13282-C01 and C02. LR was supported by an Aquagenomics postdoctoral contract and BGP was supported by an Isidro Parga Pondal research fellowship from the Xunta de Galicia (Spain).S
An Expressed Sequence Tag (EST)-enriched genetic map of turbot (Scophthalmus maximus): a useful framework for comparative genomics across model and farmed teleosts
[Background]
The turbot (Scophthalmus maximus) is a relevant species in European aquaculture. The small turbot genome provides a source for genomics strategies to use in order to understand the genetic basis of productive traits, particularly those related to sex, growth and pathogen resistance. Genetic maps represent essential genomic screening tools allowing to localize quantitative trait loci (QTL) and to identify candidate genes through comparative mapping. This information is the backbone to develop marker-assisted selection (MAS) programs in aquaculture. Expressed sequenced tag (EST) resources have largely increased in turbot, thus supplying numerous type I markers suitable for extending the previous linkage map, which was mostly based on anonymous loci. The aim of this study was to construct a higher-resolution turbot genetic map using EST-linked markers, which will turn out to be useful for comparative mapping studies.
[Results]
A consensus gene-enriched genetic map of the turbot was constructed using 463 SNP and microsatellite markers in nine reference families. This map contains 438 markers, 180 EST-linked, clustered at 24 linkage groups. Linkage and comparative genomics evidences suggested additional linkage group fusions toward the consolidation of turbot map according to karyotype information. The linkage map showed a total length of 1402.7 cM with low average intermarker distance (3.7 cM; ~2 Mb). A global 1.6:1 female-to-male recombination frequency (RF) ratio was observed, although largely variable among linkage groups and chromosome regions. Comparative sequence analysis revealed large macrosyntenic patterns against model teleost genomes, significant hits decreasing from stickleback (54%) to zebrafish (20%). Comparative mapping supported particular chromosome rearrangements within Acanthopterygii and aided to assign unallocated markers to specific turbot linkage groups.
[Conclusions]
The new gene-enriched high-resolution turbot map represents a useful genomic tool for QTL identification, positional cloning strategies, and future genome assembling. This map showed large synteny conservation against model teleost genomes. Comparative genomics and data mining from landmarks will provide straightforward access to candidate genes, which will be the basis for genetic breeding programs and evolutionary studies in this species.This study was supported by the projects: Consolider Ingenio Aquagenomics (CSD200700002), Spanish Ministerio de Ciencia e Innovación (AGL2009-13273), and Xunta de Galicia local Government (09MMA011261PR). We are indebted to Lucía Insua, María Portela, Susana Sánchez, María López, Mónica Otero and Sonia Gómez for technical assistance. B.G. Pardo was supported by an Isidro Parga Pondal research fellowship from Xunta de Galicia (Spain)
Integrative Transcriptome, Genome and Quantitative Trait Loci Resources Identify Single Nucleotide Polymorphisms in Candidate Genes for Growth Traits in Turbot
Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotide polymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish speciesThis work was funded by Spanish Ministry of Economy and Competitiveness and European Regional Development Funds (AGL2012-35904), and Ministry of Science and Innovation (Consolider Ingenio, Aquagenomics, CSD200700002). DR was supported by a FPU fellowship funded by Spanish Ministry of Education, Culture and Sport. Thanks to Lucía Ínsua for technical assistance. We thank the High-Throughput Genomics Group at the Wellcome Trust Centre for Human Genetics for the generation of the sequencing data, and the Spanish National Genotyping Center (CEGEN-ISCIII)-USC node for SNP genotyping support. We acknowledge the support of the Centro de Supercomputación de Galicia (CESGA) in the completion of this workS