159 research outputs found
Interaction paths promote module integration and network-level robustness of spliceosome to cascading effects
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPThe functionality of distinct types of protein networks depends on the patterns of protein-protein interactions. A problem to solve is understanding the fragility of protein networks to predict system malfunctioning due to mutations and other errors. Spec8111CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2017/08406-7, 2017/06994-9We thank Ana Paula Assis, Pâmela C. Santana and Leandro Giacobelli for helpful comments. PRG was supported by CNPq and FAPESP (2017/08406-7). PPC was supported by FAPESP (2017/06994-9). MC was supported by a PMP/BS postdoctoral fellowship (UFPR/UNIVALI 4
Nested species-rich networks of scavenging vertebrates support high levels of interspecific competition
Disentangling the processes that shape the organization of ecological assemblages and its implications for species coexistence is one of the foremost challenges of ecology. Although insightful advances have recently related community composition and structure with species coexistence in mutualistic and antagonistic networks, little is known regarding other species assemblages, such as those of scavengers exploiting carrion. Here we studied seven assemblages of scavengers feeding on ungulate carcasses in mainland Spain. We used dynamical models to investigate if community composition, species richness and structure (nestedness) affect species coexistence at carcasses. Scavenging networks showed a nested pattern in sites where highly efficient, obligate scavengers (i.e., vultures) were present and a non- nested pattern everywhere else. Griffon Vulture ( Gyps fulvus ) and certain meso- facultative mammalian scavengers (i.e., red fox, Vulpes vulpes, and stone marten, Martes foina ) were the main species contributing to nestedness. Assemblages with vultures were also the richest ones in species. Nested species- rich assemblages with vulture presence were associated with high carcass consumption rates, indicating higher interspecific competition at the local scale. However, the proportion of species stopping the consumption of carrion (as derived from the competitive dynamic model) stabilized at high richness and nestedness levels. This suggests that high species richness and nestedness may characterize scavenging networks that are robust to high levels of interspecific competition for carrion. Some facilitative interactions driven by vultures and major facultative scavengers could be behind these observations. Our findings are relevant for understanding species' coexistence in highly competitive systemsE. Sebastián- González and P. R. Guimarães benefited from FAPESP Research Foundation grants numbers 2011/17968- 2 and 2009/054422- 8, respectively; E. Sebastián- González is currently funded under the NSF grant NSF Award #1345247, M. Moleón by a postdoctoral grant from the Spanish Ministry of Education (Plan Nacional de I+D+I 2008- 2011), J. P. Gibert by an Other Fellowship and SBS Special Funds (U. of N.), and P. Mateo-Tomás by a postdoctoral grant of the Junta de Comunidades de Castilla-La Mancha and Fondo Social Europeo. The study was supported by the Spanish Ministry of Science and Innovation through projects 23/2007 ICTS- RBD, CGL2009- 12753- C02- 02, and CGL2012- 40013- C02- 02, FEDER funds, the Generalitat Valenciana through project ACOMP/2012/147, and the Junta de Andalucía through project RNM- 192
Iliac artery false aneurysm twelve years after allograft nephrectomy
We report a case of a non-infected right external iliac artery false aneurysm. The patient was a
44 year-old woman on chronic peritoneal dialysis had had an allograft nephrectomy 12 years before and who presented with acute abdominal pain. Ultrasound and CT-scan showed a saccular
aneurysm arising from the right external iliac artery. A large false aneurysm was identified during surgery, from donor arterial vessel remaining in situ after graft nephrectomy. Resection of the false
aneurysm, with ligation of the right external iliac artery and interposition of a femorofemoral graft was
successfully performed, with an uneventful post-operative recovery. False aneurysms after renal allograft nephrectomy are very rare. To our knowledge, this is the longest reported period of time between na nephrectomy and clinical evidence of a false aneurysm.info:eu-repo/semantics/publishedVersio
An analysis of synteny of Arachis with Lotus and Medicago sheds new light on the structure, stability and evolution of legume genomes
<p>Abstract</p> <p>Background</p> <p>Most agriculturally important legumes fall within two sub-clades of the Papilionoid legumes: the Phaseoloids and Galegoids, which diverged about 50 Mya. The Phaseoloids are mostly tropical and include crops such as common bean and soybean. The Galegoids are mostly temperate and include clover, fava bean and the model legumes <it>Lotus </it>and <it>Medicago </it>(both with substantially sequenced genomes). In contrast, peanut (<it>Arachis hypogaea</it>) falls in the Dalbergioid clade which is more basal in its divergence within the Papilionoids. The aim of this work was to integrate the genetic map of <it>Arachis </it>with <it>Lotus </it>and <it>Medicago </it>and improve our understanding of the <it>Arachis </it>genome and legume genomes in general. To do this we placed on the <it>Arachis </it>map, comparative anchor markers defined using a previously described bioinformatics pipeline. Also we investigated the possible role of transposons in the patterns of synteny that were observed.</p> <p>Results</p> <p>The <it>Arachis </it>genetic map was substantially aligned with <it>Lotus </it>and <it>Medicago </it>with most synteny blocks presenting a single main affinity to each genome. This indicates that the last common whole genome duplication within the Papilionoid legumes predated the divergence of <it>Arachis </it>from the Galegoids and Phaseoloids sufficiently that the common ancestral genome was substantially diploidized. The <it>Arachis </it>and model legume genomes comparison made here, together with a previously published comparison of <it>Lotus </it>and <it>Medicago </it>allowed all possible <it>Arachis-Lotus-Medicago </it>species by species comparisons to be made and genome syntenies observed. Distinct conserved synteny blocks and non-conserved regions were present in all genome comparisons, implying that certain legume genomic regions are consistently more stable during evolution than others. We found that in <it>Medicago </it>and possibly also in <it>Lotus</it>, retrotransposons tend to be more frequent in the variable regions. Furthermore, while these variable regions generally have lower densities of single copy genes than the more conserved regions, some harbor high densities of the fast evolving disease resistance genes.</p> <p>Conclusion</p> <p>We suggest that gene space in Papilionoids may be divided into two broadly defined components: more conserved regions which tend to have low retrotransposon densities and are relatively stable during evolution; and variable regions that tend to have high retrotransposon densities, and whose frequent restructuring may fuel the evolution of some gene families.</p
Nestedness across biological scales
Biological networks pervade nature. They describe systems throughout all levels of biological organization, from molecules regulating metabolism to species interactions that shape ecosystem dynamics. The network thinking revealed recurrent organizational patterns in complex biological systems, such as the formation of semi-independent groups of connected elements (modularity) and non-random distributions of interactions among elements. Other structural patterns, such as nestedness, have been primarily assessed in ecological networks formed by two non-overlapping sets of elements; information on its occurrence on other levels of organization is lacking. Nestedness occurs when interactions of less connected elements form proper subsets of the interactions of more connected elements. Only recently these properties began to be appreciated in one-mode networks (where all elements can interact) which describe a much wider variety of biological phenomena. Here, we compute nestedness in a diverse collection of one-mode networked systems from six different levels of biological organization depicting gene and protein interactions, complex phenotypes, animal societies, metapopulations, food webs and vertebrate metacommunities. Our findings suggest that nestedness emerge independently of interaction type or biological scale and reveal that disparate systems can share nested organization features characterized by inclusive subsets of interacting elements with decreasing connectedness. We primarily explore the implications of a nested structure for each of these studied systems, then theorize on how nested networks are assembled. We hypothesize that nestedness emerges across scales due to processes that, although system-dependent, may share a general.Facultad de Ciencias Naturales y Muse
Nestedness across biological scales
Biological networks pervade nature. They describe systems throughout all levels of biological organization, from molecules regulating metabolism to species interactions that shape ecosystem dynamics. The network thinking revealed recurrent organizational patterns in complex biological systems, such as the formation of semi-independent groups of connected elements (modularity) and non-random distributions of interactions among elements. Other structural patterns, such as nestedness, have been primarily assessed in ecological networks formed by two non-overlapping sets of elements; information on its occurrence on other levels of organization is lacking. Nestedness occurs when interactions of less connected elements form proper subsets of the interactions of more connected elements. Only recently these properties began to be appreciated in one-mode networks (where all elements can interact) which describe a much wider variety of biological phenomena. Here, we compute nestedness in a diverse collection of one-mode networked systems from six different levels of biological organization depicting gene and protein interactions, complex phenotypes, animal societies, metapopulations, food webs and vertebrate metacommunities. Our findings suggest that nestedness emerge independently of interaction type or biological scale and reveal that disparate systems can share nested organization features characterized by inclusive subsets of interacting elements with decreasing connectedness. We primarily explore the implications of a nested structure for each of these studied systems, then theorize on how nested networks are assembled. We hypothesize that nestedness emerges across scales due to processes that, although system-dependent, may share a general.Facultad de Ciencias Naturales y Muse
Reference genes for quantitative reverse transcription-polymerase chain reaction expression studies in wild and cultivated peanut
<p>Abstract</p> <p>Background</p> <p>Wild peanut species (<it>Arachis </it>spp.) are a rich source of new alleles for peanut improvement. Plant transcriptome analysis under specific experimental conditions helps the understanding of cellular processes related, for instance, to development, stress response, and crop yield. The validation of these studies has been generally accomplished by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) which requires normalization of mRNA levels among samples. This can be achieved by comparing the expression ratio between a gene of interest and a reference gene which is constitutively expressed. Nowadays there is a lack of appropriate reference genes for both wild and cultivated <it>Arachis</it>. The identification of such genes would allow a consistent analysis of qRT-PCR data and speed up candidate gene validation in peanut.</p> <p>Results</p> <p>A set of ten reference genes were analyzed in four <it>Arachis </it>species (<it>A. magna</it>; <it>A. duranensis</it>; <it>A. stenosperma </it>and <it>A. hypogaea</it>) subjected to biotic (root-knot nematode and leaf spot fungus) and abiotic (drought) stresses, in two distinct plant organs (roots and leaves). By the use of three programs (GeNorm, NormFinder and BestKeeper) and taking into account the entire dataset, five of these ten genes, <it>ACT1 </it>(actin depolymerizing factor-like protein), <it>UBI1 </it>(polyubiquitin), <it>GAPDH </it>(glyceraldehyde-3-phosphate dehydrogenase), <it>60S </it>(60S ribosomal protein L10) and <it>UBI2 </it>(ubiquitin/ribosomal protein S27a) emerged as top reference genes, with their stability varying in eight subsets. The former three genes were the most stable across all species, organs and treatments studied.</p> <p>Conclusions</p> <p>This first in-depth study of reference genes validation in wild <it>Arachis </it>species will allow the use of specific combinations of secure and stable reference genes in qRT-PCR assays. The use of these appropriate references characterized here should improve the accuracy and reliability of gene expression analysis in both wild and cultivated Arachis and contribute for the better understanding of gene expression in, for instance, stress tolerance/resistance mechanisms in plants.</p
Nestedness across biological scales
Biological networks pervade nature. They describe systems throughout all levels of biological organization, from molecules regulating metabolism to species interactions that shape ecosystem dynamics. The network thinking revealed recurrent organizational patterns in complex biological systems, such as the formation of semi-independent groups of connected elements (modularity) and non-random distributions of interactions among elements. Other structural patterns, such as nestedness, have been primarily assessed in ecological networks formed by two non-overlapping sets of elements; information on its occurrence on other levels of organization is lacking. Nestedness occurs when interactions of less connected elements form proper subsets of the interactions of more connected elements. Only recently these properties began to be appreciated in one-mode networks (where all elements can interact) which describe a much wider variety of biological phenomena. Here, we compute nestedness in a diverse collection of one-mode networked systems from six different levels of biological organization depicting gene and protein interactions, complex phenotypes, animal societies, metapopulations, food webs and vertebrate metacommunities. Our findings suggest that nestedness emerge independently of interaction type or biological scale and reveal that disparate systems can share nested organization features characterized by inclusive subsets of interacting elements with decreasing connectedness. We primarily explore the implications of a nested structure for each of these studied systems, then theorize on how nested networks are assembled. We hypothesize that nestedness emerges across scales due to processes that, although system-dependent, may share a general.Facultad de Ciencias Naturales y Muse
Caracterização da fauna de moscas-das-frutas (Diptera: Tephritidae) na região de Ponta Grossa, Paraná, Brasil
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