320 resultados para SUBFAMILIES
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Phytochemical studies of Hortia brasiliana and Hortia oreadica (Rutaceae) have led to the identification of three novel dihydrocinnamic acids: 5-methoxy-2,2-dimethyl-2H-1-benzopyran-8-propanoic acid, 5,6-dimethoxy-2,2-dimethyl-2H-1-benzopyran-8-propanoic acid and erythro-2-hydroxy-4-methoxy-3-(1,2,3-trihydroxy-3-methylbutyl) benzenepropanoic acid from H. brasiliana and the second compound and six known dihydrocinnamic acids from H. oreadica. Engler included Hortia as the single Neotropical genus in the Toddalioideae subtribe Toddaliinae. However, the range of dihydrocinnamic acid derivatives found in H. brasiliana and H. oreadica show that they contain similar compounds to other species of Hortia and clearly point to their phytochemical affinities with other Rutoideae species. (C) 2012 Elsevier Ltd. All rights reserved.
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Abstract Background The naturally-acquired immune response to Plasmodium vivax variant antigens (VIR) was evaluated in individuals exposed to malaria and living in different endemic areas for malaria in the north of Brazil. Methods Seven recombinant proteins representing four vir subfamilies (A, B, C, and E) obtained from a single patient from the Amazon Region were expressed in Escherichia coli as soluble glutathione S-transferase fusion proteins. The different recombinant proteins were compared by ELISA with regard to the recognition by IgM, IgG, and IgG subclass of antibodies from 200 individuals with patent infection. Results The frequency of individuals that presented antibodies anti-VIR (IgM plus IgG) during the infection was 49%. The frequencies of individuals that presented IgM or IgG antibodies anti-VIR were 29.6% or 26.0%, respectively. The prevalence of IgG antibodies against recombinant VIR proteins was significantly lower than the prevalence of antibodies against the recombinant proteins representing two surface antigens of merozoites of P. vivax: AMA-1 and MSP119 (57.0% and 90.5%, respectively). The cellular immune response to VIR antigens was evaluated by in vitro proliferative assays in mononuclear cells of the individuals recently exposed to P. vivax. No significant proliferative response to these antigens was observed when comparing malaria-exposed to non-exposed individuals. Conclusion This study provides evidence that there is a low frequency of individuals responding to each VIR antigens in endemic areas of Brazil. This fact may explain the host susceptibility to new episodes of the disease.
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Abstract Background Heavy metal Resistance-Nodulation-Division (HME-RND) efflux systems help Gram-negative bacteria to keep the intracellular homeostasis under high metal concentrations. These proteins constitute the cytoplasmic membrane channel of the tripartite RND transport systems. Caulobacter crescentus NA1000 possess two HME-RND proteins, and the aim of this work was to determine their involvement in the response to cadmium, zinc, cobalt and nickel, and to analyze the phylogenetic distribution and characteristic signatures of orthologs of these two proteins. Results Expression assays of the czrCBA operon showed significant induction in the presence of cadmium and zinc, and moderate induction by cobalt and nickel. The nczCBA operon is highly induced in the presence of nickel and cobalt, moderately induced by zinc and not induced by cadmium. Analysis of the resistance phenotype of mutant strains showed that the ΔczrA strain is highly sensitive to cadmium, zinc and cobalt, but resistant to nickel. The ΔnczA strain and the double mutant strain showed reduced growth in the presence of all metals tested. Phylogenetic analysis of the C. crescentus HME-RND proteins showed that CzrA-like proteins, in contrast to those similar to NczA, are almost exclusively found in the Alphaproteobacteria group, and the characteristic protein signatures of each group were highlighted. Conclusions The czrCBA efflux system is involved mainly in response to cadmium and zinc with a secondary role in response to cobalt. The nczCBA efflux system is involved mainly in response to nickel and cobalt, with a secondary role in response to cadmium and zinc. CzrA belongs to the HME2 subfamily, which is almost exclusively found in the Alphaproteobacteria group, as shown by phylogenetic analysis. NczA belongs to the HME1 subfamily which is more widespread among diverse Proteobacteria groups. Each of these subfamilies present distinctive amino acid signatures.
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Zusammenfassung der Dissertation von Markus Böhm 'Klonierung, Sequenzierung und Funktion der beiden SAPK-Mitglieder JNK und p38 MAPK des marinen Schwamms S. domuncula' am Fachbereich Biologie der Johannes Gutenberg-Universität Mainz: Da Schwämme zu den einfachsten Metazoen gehören, eignen sie sich gut zur Erforschung von Signaltransduktionsprozessen. Die SAPKs stellen hoch konservierte Signalmoleküle dar, die durch viele Zellstress-auslösende Faktoren aktiviert werden und in zahlreichen biologischen Prozessen involviert sind.Im Rahmen dieser Arbeit wurden zwei SAPK-Gene aus S. domuncula isoliert. Ihre abgeleiteten Aminosäuresequenzen wiesen die höchsten Homologien zu den Mitgliedern der SAPK1/JNK- und SAPK2/p38 MAPK-Subfamilie der Metazoen auf. Die geringste Übereinstimmung existierte gegenüber der einzigen SAPK der Hefe (HOG1). Beide Gene des Schwamms besaßen zudem eine außerordentlich hohe Übereinstimmung hinsichtlich ihrer Exon/Intron-Strukturen. Diese Ergebnisse deuten daraufhin, dass die SAPKs der multizellulären Tiere durch Duplikation eines HOG1-verwandten Vorläufergens entstanden sind. Durch den Vergleich der Intronpositionen mit denen von SAPK-Genen aus D. melanogaster, C. elegans und H. sapiens wurde ersichtlich, dass die Positionen der nichtkodierenden Sequenzbereiche dieser Gene hoch konserviert sind. Western Blot-Analysen demonstrierten, dass beide Schwamm-Kinasen durch hyperosmotischen Stress, LPS und den Phosphataseinhibitor Okadainsäure aktiviert werden. Außerdem wurde durch Versuche mit HOG1-defizienten Hefemutanten gezeigt, dass sie die Funktion des HOG1-Proteins in S. cerevisiae vollständig übernehmen können. Da die aktivierten Kinasen des Schwamms wie HOG1 im Nukleus der Hefezellen akkumuliert werden, müssen die Kerntransportmechanismen der SAPKs ebenfalls evolutionär erhalten sein.
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CYP3A verstoffwechselt mehr als 50% aller gegenwärtig in der Therapie eingesetzten Wirkstoffe, die häufig an klinisch relevanten Arzneimitttel-Wechselwirkungen beteiligt sind. Das Verständnis über die Bedeutung und die Regulation von einzelnen CYP3A Genen in der Pharmakologie und Physiologie ist unvollständig. Wir untersuchten die Evolution des CYP3 Genlokus über einen Zeitraum von 450 Millionen Jahre mittels genomischer Sequenzen von 16 Tierarten. Neue CYP3 Unterfamilien (CYP3B, C und D) entstanden über eine beschleunigte Evolution aus CYP3A Vorstufen von Clupeocephala Spezies. Ausgeprägte funktionelle Unterschiede traten zwischen CYP3A in Säugern und Clupeocephala CYP3 auf. Alle amnioten CYP3A Gene entwickelten sich aus zwei CYP3A Urgenen. Aufgrund der Entstehung von Säugern mit Plazenta ging eines von ihnen verloren während das andere eine neue genomische Umgebung infolge einer Translokation erlangte. In Primaten unterzog sich CYP3A mit mehreren Genduplikationen, Deletionen, Pseudogenisierung und Genkonversionen einer raschen evolutionären Veränderung. Die Entwicklung von CYP3A in Schmalnasenaffen (Alte Welt Affen, große Menschenaffen und Menschen) unterschieden sich wesentlich von Neue Welt Primaten (z.B. gewöhnlichen Krallenaffen) und Feuchtnasenaffen (z.B. Galago). Stellvertretend für die CYP3A Protein-codierende Sequenz entdeckten wir zwei frühe Episoden von besonders starker positiver Selektion: (1) auf CYP3A7 in der frühen hominoiden Evolution, welche im fetalen Zeitraum von einer Einschränkung der hepatischen Expression begleitet war, und (2) auf humanes CYP3A4 im Anschluss an die Teilung der Abstammungslinie in Schimpansen und Mensch. In Übereinstimmung mit diesen Befunden beeinflussen drei von vier positiv ausgewählten Aminosäuren, die in früheren biochemischen CYP3A Studien untersucht wurden, die Aktivität und Regioselektivität. Es ist somit naheliegend, dass CYP3A7 und CYP3A4 katalytische Funktionen erworben haben können, die besonders wichtig waren für die Evolution von Hominoiden und Menschen. Die Charakterisierung von CYP3A Promotoren in Primaten zeigte eine Anreicherung von ER6 Elementen in CYP3A Promotoren von Primaten und einen Trend in Richtung Erhöhung der ER6 Enstehung entlang den Abstammungslinien, die zu humanen und Schimpansen CYP3A4 führten. Die steigende Anzahl an ER6 Elementen kann durch die ausgeprägte CYP3A4 Induzierbarkeit und Expressionsvariabilität im Menschen verursacht sein.
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The new goblin spider genus Prethopalpus is restricted to the Australasian tropics, from the lower Himalayan Mountains in Nepal and India to the Malaysian Peninsula, Indonesia, Papua New Guinea, and Australia. Prethopalpus contains those species with a swollen palpal patella, which is one to two times the size of the femur, together with a cymbium and bulb that is usually separated, although it is largely fused in four species. The type species Opopaea fosuma Burger et al. from Sumatra, and Camptoscaphiella infernalis Harvey and Edward from Western Australia are newly transferred to Prethopalpus. The genus consists of 41 species of which 39 are newly described: P. ilam Baehr (♂, ♀) from Nepal; P. khasi Baehr (♂), P. madurai Baehr (♂), P. mahanadi Baehr (♂, ♀), and P. meghalaya Baehr (♂, ♀) from India; P. bali Baehr (♂), P. bellicosus Baehr and Thoma (♂, ♀), P. brunei Baehr (♂, ♀), P. deelemanae Baehr and Thoma (♂), P. java Baehr (♂, ♀), P. kranzae Baehr (♂), P. kropfi Baehr (♂, ♀), P. leuser Baehr (♂, ♀), P. magnocularis Baehr and Thoma (♂), P. pahang Baehr (♂), P. perak Baehr (♂, ♀), P. sabah Baehr (♂, ♀), P. sarawak Baehr (♂), P. schwendingeri Baehr (♂, ♀), and P. utara Baehr (♂, ♀) from Indonesia and Malaysia; and P. alexanderi Baehr and Harvey (♂), P. attenboroughi Baehr and Harvey (♂), P. blosfeldsorum Baehr and Harvey (♂), P. boltoni Baehr and Harvey (♂, ♀), P. callani Baehr and Harvey (♂, ♀), P. cooperi Baehr and Harvey (♂), P. eberhardi Baehr and Harvey (♂, ♀), P. framenaui Baehr and Harvey (♂, ♀), P. humphreysi Baehr and Harvey (♂, ♀), P. kintyre Baehr and Harvey (♂), P. scanloni Baehr and Harvey (♂), P. pearsoni Baehr and Harvey (♂), P. julianneae Baehr and Harvey (♂), P. maini Baehr and Harvey (♂, ♀), P. marionae Baehr and Harvey (♂, ♀), P. platnicki Baehr and Harvey (♂, ♀), P. oneillae Baehr and Harvey (♂), P. rawlinsoni Baehr and Harvey (♂), and P. tropicus Baehr and Harvey (♂, ♀) from Australia and Papua New Guinea. Three separate keys to species from different geographical regions are provided. Most species are recorded from single locations and only three species are more widely distributed. A significant radiation of blind troglobites comprising 14 species living in subterranean ecosystems in Western Australia is discussed. These include several species that lack abdominal scuta, a feature previously used to define subfamilies of Oonopidae.
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Members of the plant NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER (NRT1/PTR) family display protein sequence homology with the SLC15/PepT/PTR/POT family of peptide transporters in animals. In comparison to their animal and bacterial counterparts, these plant proteins transport a wide variety of substrates: nitrate, peptides, amino acids, dicarboxylates, glucosinolates, IAA, and ABA. The phylogenetic relationship of the members of the NRT1/PTR family in 31 fully sequenced plant genomes allowed the identification of unambiguous clades, defining eight subfamilies. The phylogenetic tree was used to determine a unified nomenclature of this family named NPF, for NRT1/PTR FAMILY. We propose that the members should be named accordingly: NPFX.Y, where X denotes the subfamily and Y the individual member within the species.
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Amino acids are necessary for all living cells and organisms. Specialized transporters mediate the transfer of amino acids across plasma membranes. Malfunction of these proteins can affect whole-body homoeostasis giving raise to diverse human diseases. Here, we review the main features of the SLC3 and SLC7 families of amino acid transporters. The SLC7 family is divided into two subfamilies, the cationic amino acid transporters (CATs), and the L-type amino acid transporters (LATs). The latter are the light or catalytic subunits of the heteromeric amino acid transporters (HATs), which are associated by a disulfide bridge with the heavy subunits 4F2hc or rBAT. These two subunits are glycoproteins and form the SLC3 family. Most CAT subfamily members were functionally characterized and shown to function as facilitated diffusers mediating the entry and efflux of cationic amino acids. In certain cells, CATs play an important role in the delivery of L-arginine for the synthesis of nitric oxide. HATs are mostly exchangers with a broad spectrum of substrates and are crucial in renal and intestinal re-absorption and cell redox balance. Furthermore, the role of the HAT 4F2hc/LAT1 in tumor growth and the application of LAT1 inhibitors and PET tracers for reduction of tumor progression and imaging of tumors are discussed. Finally, we describe the link between specific mutations in HATs and the primary inherited aminoacidurias, cystinuria and lysinuric protein intolerance.
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Gammaherpesviruses, including the human pathogens Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, are causative agents of lymphomas and other malignancies. The structural characterization of these viruses has been limited due to difficulties in obtaining adequate amount of virion particles. Here we report the first three-dimensional structural characterization of a whole gammaherpesvirus virion by an emerging integrated approach of cryo-electron tomography combined with single-particle cryo-electron microscopy, using murine gammaherpesvirus-68 (MHV-68) as a model system. We found that the MHV-68 virion consists of distinctive envelope and tegument compartments, and a highly conserved nucleocapsid. Two layers of tegument are identified: an inner tegument layer tethered to the underlying capsid and an outer, flexible tegument layer conforming to the overlying, pleomorphic envelope, consistent with the sequential viral tegumentation process inside host cells. Surprisingly, comparison of the MHV-68 virion and capsid reconstructions shows that the interactions between the capsid and inner tegument proteins are completely different from those observed in alpha and betaherpesviruses. These observations support the notion that the inner layer tegument across different subfamilies of herpesviruses has evolved significantly to confer specific characteristics related to viral-host interactions, in contrast to a highly conserved capsid for genome encapsidation and protection.
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Integrin adhesion molecules have both positive and negative potential in the regulation of peripheral blood T cell (PB T cell) activation, yet their mechanism of action in the mediation of human T lymphocyte function remains largely undefined. The goals of this study then were to elucidate integrin signaling mechanisms in PB T cells.^ By ligating $\beta$1 integrins with mAb 18D3, it was demonstrated that costimulation of PB T cell proliferation induced by coimmobilizing antibodies specific for $\beta$1, $\beta$2, and $\beta$7 integrin subfamilies in conjunction with the anti-CD3 mAb OKT3 was inhibited. Costimulation of T cell proliferation induced by non-integrins CD4, CD26, CD28, CD44, CD45RA, or CD45RO was unaffected. Inhibition of costimulation correlated with diminished IL-2 production. In his manner, $\beta$1 integrins could regulate heterologous integrins of the $\beta$2 and $\beta$7 subfamilies in a transdominant fashion. It was also demonstrated that integrin costimulation of T cell activation was acutely sensitive to the structural conformation of $\beta$1 integrins. Using the cyclic hexapeptide CWLDVC (TBC772, which is based on the $\alpha4\beta1$ integrin binding site in fibronectin) in soluble form, it was shown that integrins locked into a conformation displaying a neo-epitope called the ligand induced binding site (LIBS) recognized by mAb 15/7 were inhibited from sending mitogenic signals to T cells. When BSA-conjugated TBC772 was coimmobilized with anti-CD3 mAb OKT3, costimulation of proliferation occurred. This suggested that temporally uncoupling integrin receptor occupancy from receptor crosslinking inhibited $\beta$1 integrin signaling mechanisms. When subsets of PB T cells were examined to determine those initially activated by integrins within 6 hours of activation, costimulation induced intracellular accumulation of IL-2 predominantly in the CD4$\sp+$ and CD45RO$\sp+$ T cell subsets. This was similar to a number of PB T cell costimulatory molecules including CD26, CD43, CD44. Only CD28 costimulated IL-2 production from both CD45RA$\sp+$ and CD45RO$\sp+$ subpopulations.^ The GTPase Rho has been implicated in regulating integrin mediated stress fiber formation and anchorage dependent growth in fibroblasts, so studies were initiated to determine if Rho played a role in integrin dependent T cell function. In order to perform this, a technique based on scrape-loading was developed to incorporate macromolecules into PB T cells that maintained their functional activity. With this technique, C3 exoenzyme from Clostridium botulinum was incorporated into PB T cells. C3 ADP-ribosylates Rho proteins on Asn$\sp{41},$ which is in close proximity to the Rho effector domain, rendering it inactive. It was demonstrated that functional Rho is not required for basal or upregulated PB T cell adhesion to $\beta$1 integrin substrates, however PB T cell homotypic aggregation induced by PMA, which is an event mediated predominantly by the integrin $\rm\alpha L\beta2,$ was delayed. PB T cells lacking Rho function displayed altered cell morphology on $\beta$1 integrin ligands, producing stellate, dendritic-like pseudopodia. Rho activity was also found to be required for integrin dependent costimulation of proliferation. When intracellular accumulation of IL-2 was measured, inactivation of Rho prevented both integrin and CD28 costimulatory activity. Rho was identified to lie upstream of signals mediating PKC activation and Ca$\sp{++}$ fluxes, as PMA and ionomycin activation of PB T cells was unaffected by the inactivation of Rho. ^
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Traumatic brain injury (TBI) often results in disruption of the blood brain barrier (BBB), which is an integral component to maintaining the central nervous system homeostasis. Recently cytosolic calcium levels ([Ca2+]i), observed to elevate following TBI, have been shown to influence endothelial barrier integrity. However, the mechanism by which TBI-induced calcium signaling alters the endothelial barrier remains unknown. In the present study, an in vitro BBB model was utilized to address this issue. Exposure of cells to biaxial mechanical stretch, in the range expected for TBI, resulted in a rapid cytosolic calcium increase. Modulation of intracellular and extracellular Ca2+ reservoirs indicated that Ca2+ influx is the major contributor for the [Ca2+]i elevation. Application of pharmacological inhibitors was used to identify the calcium-permeable channels involved in the stretch-induced Ca2+ influx. Antagonist of transient receptor potential (TRP) channel subfamilies, TRPC and TRPP, demonstrated a reduction of the stretch-induced Ca2+ influx. RNA silencing directed at individual TRP channel subtypes revealed that TRPC1 and TRPP2 largely mediate the stretch-induced Ca2+ response. In addition, we found that nitric oxide (NO) levels increased as a result of mechanical stretch, and that inhibition of TRPC1 and TRPP2 abolished the elevated NO synthesis. Further, as myosin light chain (MLC) phosphorylation and actin cytoskeleton rearrangement are correlated with endothelial barrier disruption, we investigated the effect mechanical stretch had on the myosin-actin cytoskeleton. We found that phosphorylated MLC was increased significantly by 10 minutes post-stretch, and that inhibition of TRP channel activity or NO synthesis both abolished this effect. In addition, actin stress fibers formation significantly increased 2 minutes post-stretch, and was abolished by treatment with TRP channel inhibitors. These results suggest that, in brain endothelial cells, TRPC1 and TRPP2 are activated by TBI-mechanical stress and initiate actin-myosin contraction, which may lead to disruption of the BBB.
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The family Munnopsidae was the most abundant and diverse among 22 isopod families collected by the ANDEEP deep-sea expeditions in 2002 and 2005 in the Atlantic sector of the Southern Ocean. A total of 219 species from 31 genera and eight subfamilies were analysed. Only 20% species were known to science, and 11% of these were reported outside the ANDEEP area mainly from other parts of the SO or the South Atlantic deep sea. One hundred and five species (50%) were rare, occurring at only 1 or 2 stations. Seventy-two percent of all munnopsid specimens belong to the most numerous 25 species with a total abundance of more than 75 specimens; 5 of these species (40% of all specimens) belong to the main genera of the world munnopsid fauna, Eurycope, Disconectes, Betamorpha, and Ilyarachna. About half of all munnopsid specimens and 34% of all species belong to the subfamily Eurycopinae, which is followed in occurrence by the Lipomerinae (19%). Munnopsinae is the poorest represented subfamily (1.5%). The composition of the subfamilies for the munnopsid fauna of the ANDEEP area differs from that of northern faunas. Lipomerinae show a lower percentage (7%) in the North Atlantic and are absent in the Arctic and in the North Pacific. This subfamily is considered as young and having a centre of origin and diversification in the Southern Ocean. The analyses of the taxonomic diversity and the distribution of Antarctic munnopsids and the distribution of the world fauna of all genera of the family revealed that species richness and diversity of the genera are highest in the ANDEEP area. The investigated fauna is characterised also by high percentage of endemic species, the highest richness and diversity of the main munnopsid genera and subfamily Lipomerinae. This supports the hypothesis that the Atlantic sector of SO deep sea may be considered as the main contemporary centre of diversification of the Munnopsidae. It might serve as a diversity pump of species of the Munnopsidae to more northern Atlantic areas via the deep water originating in the Weddell Sea.
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The general objective of this work is to analyze the regulatory processes underlying flowering transition and inflorescence and flower development in grapevine. Most of these crucial developmental events take place within buds growing during two seasons in two consecutive years. During the first season, the shoot apical meristem within the bud differentiates all the basic elements of the shoot including flowering transition in lateral primordia and development of inflorescence primordia. These events practically end with bud dormancy. The second season, buds resume shoot growth associated to flower formation and development. In grapevine, the lateral meristems can give rise either to tendril or inflorescence primordia that are homologous organs. With this purpose, we performed global transcriptome analyses along the bud annual cycle and during inflorescence and tendril development. In addition, we approach the genomic analysis of the MIKC type MADS-box gene family in grapevine to identify all its members and assign them putative biological functions. Regarding buds developmental cycle, the results indicate that the main factors explaining the global gene expression differences were the processes of bud dormancy and active growth as well as stress responses. Non dormant buds exhibited up-regulation in functional categories typical of actively proliferating and growing cells (photosynthesis, cell cycle regulation, chromatin assembly) whereas in dormant ones the main functional categories up-regulated were associated to stress response pathways together with transcripts related to starch catabolism. Major transcriptional changes during the dormancy period were associated to the para/endodormancy, endo/ecodormancy and ecodormancy/bud break transitions. Global transcriptional analyses along tendril and inflorescence development suggested that these two homologous organs share a common transcriptional program related to cell proliferation functions. Both structures showed a progressive decrease in the expression of categories such as cell-cycle, auxin metabolism/signaling, DNA metabolism, chromatin assembly and a cluster of five transcripts belonging to the GROWTH-REGULATING FACTOR (GRF) transcription factor family, that are known to control cell proliferation in other species and determine the size of lateral organs. However, they also showed organ specific transcriptional programs that can be related to their differential organ structure and function. Tendrils showed higher transcription of genes related to photosynthesis, hormone signaling and secondary metabolism than inflorescences, while inflorescences have higher transcriptional activity for genes encoding transcription factors (especially those belonging to the MADS-box gene family). Further analysis along inflorescence development evidenced the relevance of additional functions likely related to processes of flower development such as fatty acid and lipid metabolism, jasmonate signaling and oxylipin biosynthesis. The transcriptional analyses performed highlighted the relevance of several groups of transcriptional regulators in the developmental processes studied. The expression profiles along bud development revealed significant differences for some MADS-box subfamilies in relation to other plant species, like the members of the FLC and SVP subfamilies suggesting new roles for these groups in grapevine. In this way, it was found that VvFLC2 and VvAGL15.1 could participate, together with some members of the SPL-L family, in dormancy regulation, as was shown for some of them in other woody plants. Similarly, the expression patterns of the VvFLC1, VvFUL, VvSOC1.1 (together with VvFT, VvMFT1 and VFL) genes could indicate that they play a role in flowering transition in grapevine, in parallel to their roles in other plant systems. The expression levels of VFL, the grapevine LEAFY homolog, could be crucial to specify the development of inflorescence and flower meristems instead of tendril meristems. MADS-box genes VvAP3.1 and 2, VvPI, VvAG1 and 3, VvSEP1-4, as well as VvBS1 and 2 are likely associated with the events of flower meristems and flower organs differentiation, while VvAP1 and VvFUL-L (together with VvSOC1.1, VvAGL6.2) could be involved on tendril development given their expression patterns. In addition, the biological function ofVvAP1 and VvTFL1A was analyzed using a gene silencing approach in transgenic grapevine plants. Our preliminary results suggested a possible role for both genes in the initiation and differentiation of tendrils. Finally, the genomic analysis of the MADS-box gene family in grapevine revealed differential features regarding number and expression pattern of genes putatively involved in the flowering transition process as compared to those involved in the specification of flower and fruit organ identity. Altogether, the results obtained allow identifying putative candidate genes and pathways regulating grapevine reproductive developmental processes paving the way to future experiments demonstrating specific gene biological functions. RESUMEN El objetivo general de este trabajo es analizar los procesos regulatorios subyacentes a la inducción floral así como al desarrollo de la inflorescencia y la flor en la vid. La mayor parte de estos eventos cruciales tienen lugar en las yemas a lo largo de dos estaciones de crecimiento consecutivas. Durante la primera estación, el meristemo apical contenido en la yema diferencia los elementos básicos del pámpano, lo cual incluye la inducción de la floración en los meristemos laterales y el subsiguiente desarrollo de primordios de inflorescencia. Estos procesos prácticamente cesan con la entrada en dormición de la yema. En la segunda estación, se reanuda el crecimiento del pámpano acompañado por la formación y desarrollo de las flores. En la vid, los meristemos laterales pueden dar lugar a primordios de inflorescencia o de zarcillo que son considerados órganos homólogos. Con este objetivo llevamos a cabo un estudio a nivel del transcriptoma de la yema a lo largo de su ciclo anual, así como a lo largo del desarrollo de la inflorescencia y del zarcillo. Además realizamos un análisis genómico de la familia MADS de factores transcripcionales (concretamente aquellos del tipo MIKC) para identificar todos sus miembros y tratar de asignarles posibles funciones biológicas. En cuanto al ciclo de desarrollo de la yema, los resultados indican que los principales factores que explican las diferencias globales en la expresión génica fueron los procesos de dormición de la yema y el crecimiento activo junto con las respuestas a diversos tipos de estrés. Las yemas no durmientes mostraron un incremento en la expresión de genes contenidos en categorías funcionales típicas de células en proliferación y crecimiento activo (como fotosíntesis, regulación del ciclo celular, ensamblaje de cromatina), mientras que en las yemas durmientes, las principales categorías funcionales activadas estaban asociadas a respuestas a estrés, así como con el catabolismo de almidón. Los mayores cambios observados a nivel de transcriptoma en la yema coincidieron con las transiciones de para/endodormición, endo/ecodormición y ecodormición/brotación. Los análisis transcripcionales globales a lo largo del desarrollo del zarcillo y de la inflorescencia sugirieron que estos dos órganos homólogos comparten un programa transcripcional común, relacionado con funciones de proliferación celular. Ambas estructuras mostraron un descenso progresivo en la expresión de genes pertenecientes a categorías funcionales como regulación del ciclo celular, metabolismo/señalización por auxinas, metabolismo de ADN, ensamblaje de cromatina y un grupo de cinco tránscritos pertenecientes a la familia de factores transcripcionales GROWTH-REGULATING FACTOR (GRF), que han sido asociados con el control de la proliferación celular y en determinar el tamaño de los órganos laterales en otras especies. Sin embargo, también pusieron de manifiesto programas transcripcionales que podrían estar relacionados con la diferente estructura y función de dichos órganos. Los zarcillos mostraron mayor actividad transcripcional de genes relacionados con fotosíntesis, señalización hormonal y metabolismo secundario que las inflorescencias, mientras que éstas presentaron mayor actividad transcripcional de genes codificantes de factores de transcripción (especialmente los pertenecientes a la familia MADS-box). Análisis adicionales a lo largo del desarrollo de la inflorescencia evidenciaron la relevancia de otras funciones posiblemente relacionadas con el desarrollo floral, como el metabolismo de lípidos y ácidos grasos, la señalización mediada por jasmonato y la biosíntesis de oxilipinas. Los análisis transcripcionales llevados a cabo pusieron de manifiesto la relevancia de varios grupos de factores transcripcionales en los procesos estudiados. Los perfiles de expresión estudiados a lo largo del desarrollo de la yema mostraron diferencias significativas en algunas de las subfamilias de genes MADS con respecto a otras especies vegetales, como las observadas en los miembros de las subfamilias FLC y SVP, lo cual sugiere que podrían desempeñar nuevas funciones en la vid. En este sentido, se encontró que los genes VvFLC2 y VvAGL15.1 podrían participar, junto con algunos miembros de la familia SPL-L, en la regulación de la dormición. De un modo similar, los patrones de expresión de los genes VvFLC1, VvFUL, VvSOC1.1 (junto con VvFT, VvMFT1 y VFL) podría indicar que desempeñan un papel en la regulación de la inducción de la floración en la vid, como se ha observado en otros sistemas vegetales. Los niveles de expresión de VFL, el homólogo en vid del gen LEAFY de A. thaliana podrían ser cruciales para la especificación del desarrollo de meristemos de inflorescencia y flor en lugar de meristemos de zarcillo. Los genes VvAP3.1 y 2, VvPI, VvAG1 y 3, VvSEP1-4, así como VvBS1 y 2 parecen estar asociados con los eventos de diferenciación de meristemos y órganos florales, mientras que VvAP1 y VvFUL-L (junto con VvSOC1.1 y VvAGL6.2) podrían estar implicados en el desarrollo del zarcillo dados sus patrones de expresión. Adicionalmente, se analizó la función biológica de los genes VvAP1 y VvTFL1A por medio de una estrategia de silenciamiento génico. Los datos preliminares sugieren un posible papel para ambos genes en la iniciación y diferenciación de los zarcillos. Finalmente, el análisis genómico de la familia MADS en vid evidenció diferencias con respecto a otras especies vegetales en cuanto a número de miembros y patrón de expresión en genes supuestamente implicados en la inducción de la floración, en comparación con aquellos relacionados con la especificación de identidad de órganos florales y desarrollo del fruto. En conjunto, los resultados obtenidos han permitido identificar posibles rutas y genes candidatos a participar en la regulación de los procesos de desarrollo reproductivo de la vid, sentando las bases de futuros experimentos encaminados a conocer la funciones biológicas de genes específicos.
Resumo:
Axonal outgrowth and the formation of the axon initial segment (AIS) are early events in the acquisition of neuronal polarity. The AIS is characterized by a high concentration of voltage-dependent sodium and potassium channels. However, the specific ion channel subunits present and their precise localization in this axonal subdomain vary both during development and among the types of neurons, probably determining their firing characteristics in response to stimulation. Here, we characterize the developmental expression of different subfamilies of voltage-gated potassium channels in the AISs of cultured mouse hippocampal neurons, including subunits Kv1.2, Kv2.2 and Kv7.2. In contrast to the early appearance of voltage-gated sodium channels and the Kv7.2 subunit at the AIS, Kv1.2 and Kv2.2 subunits were tethered at the AIS only after 10 days in vitro. Interestingly, we observed different patterns of Kv1.2 and Kv2.2 subunit expression, with each confined to distinct neuronal populations. The accumulation of Kv1.2 and Kv2.2 subunits at the AIS was dependent on ankyrin G tethering, it was not affected by disruption of the actin cytoskeleton and it was resistant to detergent extraction, as described previously for other AIS proteins. This distribution of potassium channels in the AIS further emphasizes the heterogeneity of this structure in different neuronal populations, as proposed previously, and suggests corresponding differences in action potential regulation.
Resumo:
El software se ha convertido en el eje central del mundo actual, una compleja creación humana que influye en la vida, negocios y comunicación de todas las personas pertenecientes a la Sociedad de la Información. El rápido crecimiento experimentado en el ámbito del desarrollo software ha permitido la creación de avanzadas estructuras tecnológicas, denominadas “Sistemas Intensivos Software”, capaces de comunicarse con otros sistemas, dispositivos, sensores y personas. A lo largo de los próximos años los sistemas se enfrentarán a una mayor complejidad, surgida de la necesidad de operar en entornos de grandes dimensiones y de comportamientos no deterministas. Los métodos y herramientas actuales no son lo suficientemente potentes para diseñar, construir,implementar y mantener sistemas intensivos software con estas características, y detener la construcción de sistemas intensivos software o construir sistemas poco flexibles o fiables no es una alternativa real. En el desarrollo de “Sistemas Intensivos Software” pueden llegar a intervenir distintas entidades o compañías software que suelen estar en ubicaciones geográficas distintas y constituidas por grandes equipos de desarrollo, multidisciplinares e incluso multilingües. Debido a la criticidad del resultado de las actividades realizadas de forma independiente en el sistema resultante, éstas se han de controlar y monitorizar para asegurar la correcta integración de todos los elementos del sistema completo. El objetivo de este proyecto es la creación de una herramienta software para dar soporte a la gestión y monitorización de la construcción e integración de sistemas intensivos software, siendo extensible también a proyectos de otra índole. La herramienta resultante se denomina Positioning System, una aplicación web del tipo SPA (Single Page Application) creada con tecnología de última generación como el framework JavaScript AngularJS y tecnología de back-end como SlimPHP. Positioning System provee la funcionalidad necesaria para la creación de proyectos, familias y subfamilias de productos que constituyen los productos software de los proyectos creados, así como la gestión de socios comerciales y gestión de contactos de dichos proyectos. Todas estas funcionalidades son fácilmente monitorizadas y controladas por gráficos estadísticos generados para cada proyecto. ABSTRACT Software has become the backbone of today’s world, a complex human creation that has an important impact in the life, business and communication of all people involved with the Information Society. The quick growth that software development has undergone for last years has enabled the creation of advanced technological structures called “Software Intensive Systems”. They are able to communicate with other systems, devices, sensors and people. Next years, systems will face more complexity. It arises from the need of operating systems of large dimensions with non-deterministic behaviors. Current methods and tools are not powerful enough to design, build, implement and maintain software intensive systems; however stopping the development or developing unreliable and non-flexible systems is not a real alternative. Software Intensive Systems” development may involve different entities or software companies which may be in different geographical locations and may be constituted by large, multidisciplinary and even multilingual development teams. Due to the criticality of the result of each conducted activity, independently in the resulting system, these activities must be controlled and monitored to ensure the proper integration of all the elements within the complete system. The goal of this project is the creation of a software tool to support the management and monitoring of the construction and integration of software intensive systems, being possible to be extended to other kind of projects. The resultant tool is called Positioning System, a web application that follows the SPA (Single Page Application) style. It was created with the latest technologies, such as, the AngularJS framework and SlimPHP. The Positioning System provides the necessary features for the creation of projects, families and subfamilies of products that constitute the software products of the created projects, as well as the management of business partners and contacts of these projects. All these features are easily monitored and controlled by statistical graphs generated for each project.