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1.
Int J Environ Sci Technol (Tehran) ; 20(7): 7925-7938, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36117955

RESUMEN

The aim of this work is to accomplish an in-depth analysis of the air pollution in the two main cities of the Bay of Algeciras (Spain). A large database of air pollutant concentrations and weather measurements were collected using a monitoring network installed throughout the region from the period of 2010-2015. The concentration parameters contain nitrogen dioxide (NO2), sulphur dioxide (SO2) and particulate matter (PM10). The analysis was developed in two monitoring stations (Algeciras and La Línea). The higher average concentration values were obtained in Algeciras for NO2 (28.850 µg/m3) and SO2 (11.966 µg/m3), and in La Línea for PM10 (30.745 µg/m3). The analysis shows patterns that coincide with human activity. One of the goals of this work is to develop a useful virtual sensor capable of achieving a more robust monitoring network, which can be used, for instance, in the case of missing data. By means of trends analysis, groups of equivalent stations were determined, implying that the values of one station could be substituted for those in the equivalent station in case of failure (e.g., SO2 weekly trends in Algeciras and Los Barrios show equivalence). On the other hand, a calculation of relative risks was developed showing that relative humidity, wind speed and wind direction produce an increase in the risk of higher pollutant concentrations. Besides, obtained results showed that wind speed and wind direction are the most important variables in the distribution of particles. The results obtained may allow administrations or citizens to support decisions.

3.
Sex Plant Reprod ; 25(2): 133-46, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22476326

RESUMEN

Sexual reproduction is essential for the propagation of higher plants. From an agronomical point of view, this is a particularly key process because fertilization guarantees fruit formation in most cultivated fruit species. In the olive, however, in spite of its agricultural importance, little attention has been paid to the study of sexual reproduction. In order to investigate the cellular and molecular mechanisms that regulate pollen-pistil interactions in the olive during the progamic phase, it is essential to first have a good knowledge of the reproductive structures involved in such interactions. This study characterizes the anatomical and ultrastructural changes in the olive pistil, beginning from the young pistil developing within the bud until the time of petal loss and visible stigma senescence. We have correlated changes in the pistil with a series of defined floral developmental stages and determined that olive pistil structures cannot be considered completely mature and ready to be pollinated and fertilized until the onset of anthesis. Our results clearly show histological and ultrastructural variation during the diverse flowering events. We discuss whether the changes observed might influence or result from pollen-pistil interactions during the progamic phase.


Asunto(s)
Flores/anatomía & histología , Flores/ultraestructura , Olea/anatomía & histología , Olea/ultraestructura , Flores/citología , Flores/crecimiento & desarrollo , Olea/citología , Olea/crecimiento & desarrollo , Almidón/metabolismo
4.
J Microsc ; 231(2): 332-41, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18778430

RESUMEN

Pollen allergens offer a dual perspective of study: some of them are considered key proteins for pollen physiology, but they are also able to trigger allergy symptoms in susceptible humans after coming in contact with their tissues. Profilin (Ole e 2 allergen) has been characterized, to some extent, as one of the major allergens from Olea europaea L. pollen, a highly allergenic species in the Mediterranean countries. In order to obtain clues regarding the biological role of this protein, we have analyzed both its cellular localization and the organization of actin throughout pollen hydration and early pollen tube germination. The localization of the cited proteins was visualized by confocal laser scanning microscopy immunofluorescence using different antibodies. Upon pollen hydration and pollen germination, a massive presence of profilin was detected close to the site of pollen tube emergence, forming a ring-like structure around the 'effective' apertural region. Profilin was also detected in the pollen exine of the germinating pollen grains and in the germination medium. After using a permeabilization-enhanced protocol for immunolocalization, profilin was also localized in the cytoplasm of the pollen tube, particularly at both the proximal and apical ends. Noticeable accumulations of actin were observed in the cytoplasm of the pollen tube; particularly, in both the apical region and the area immediately close to the aperture. Actin filaments were not observed, probably due to the need of further enhanced fixation procedures. The ultrastructural localization of profilin showed the presence of the protein in the cytoplasm of both the mature pollen grain and the pollen tube. The results shown here could be interpreted as signs of a massive dissociation of the actin-profilin complexes, mobilization of actin monomers, and therefore, an intense activity of the actin cytoskeleton. The extensive release of allergenic proteins from the pollen grain into the surrounding aqueous media, as described here for profilin, may help us to understand the mechanisms by which these allergens might come in contact with the human mucosa, therefore triggering the symptoms of allergy.


Asunto(s)
Actinas/análisis , Alérgenos/análisis , Germinación/fisiología , Olea/fisiología , Proteínas de Plantas/análisis , Antígenos de Plantas , Medios de Cultivo/química , Citoplasma/química , Microscopía Confocal , Microscopía Fluorescente , Olea/química , Tubo Polínico/química
5.
Protoplasma ; 233(1-2): 129-39, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18615237

RESUMEN

The localization of newly formed transcripts and molecules participating in pre-mRNA splicing, i.e., small nuclear ribonucleoproteins (snRNPs) and SC35 protein, in growing pollen tubes of Hyacinthus orientalis L. were analyzed in vitro and in vivo. The results indicated that the restart of RNA synthesis occurred first in the vegetative and then in the generative nucleus of both in vitro and in vivo growing pollen tubes. Changes in RNA synthesis were accompanied by the redistribution of splicing machinery elements in both vegetative and generative nuclei of the growing pollen tube. At stages of pollen tube growth when the vegetative and generative nuclei were transcriptionally active, clear differences in the distribution pattern of the splicing system components were observed in both pollen nuclei. While both small nuclear RNA with a trimethylguanosine cap on the 5' end and SC35 protein were diffusely distributed in the nucleoplasm in the vegetative nucleus, the studied antigens were only present in the areas between condensed chromatin in the generative nucleus. When the transcriptional activity of both pollen nuclei could no longer be observed at later stages of pollen tube growth, snRNPs and SC35 protein were still present in the vegetative nuclei but not in the generative nuclei. We, therefore, investigated potential differences in the spatial organization of splicing system elements during pollen tube growth. They clearly reflect differences in gene expression patterns in the vegetative and the generative cells, which may be determined by the different biological roles of angiosperm male gametophyte cells.


Asunto(s)
Hyacinthus/crecimiento & desarrollo , Hyacinthus/genética , Tubo Polínico/crecimiento & desarrollo , Tubo Polínico/genética , Empalme del ARN/genética , Transcripción Genética , Bromodesoxiuridina/metabolismo , Guanosina/análogos & derivados , Guanosina/metabolismo , Inmunoprecipitación , ARN de Planta/biosíntesis , Ribonucleoproteínas/metabolismo
6.
J Investig Allergol Clin Immunol ; 17 Suppl 1: 17-23, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18050567

RESUMEN

The olive tree is grown in many parts of the world. Its germplasm is very broad, with 250 varieties in Spain alone. Variations in the ability of pollen to germinate have been studied in detail and show conspicuous differences between varieties. However, commercial olive pollen from cultivars whose origin is unknown is the material that is commonly used for clinical and biological studies. We aim to assess the putative heterogeneity of olive cultivars with regard to the presence of several pollen allergens and to determine whether these differences have biological and clinical relevance. Previous studies show that most allergens isolated and characterized to date are highly polymorphic. Olive cultivars display wide differences in the expression levels of many allergens and in the number and molecular characteristics of the allergen isoforms expressed. These differences are maintained over the years, and are intrinsic to the genetics of each cultivar. Such broad polymorphism seems to be involved in the physiology of the olive reproductive system, which might include the adaptation of the plant to different environmental conditions, the establishment of the compatibility system, and pollen performance. The differences in allergen composition in cultivars, particularly in the Ole e 1 allergen, are responsible for the important differences in the allergenic potency of the extracts. These findings could have a number of implications for the diagnosis and therapy of olive pollen allergy. We discuss how cultivar differences affect extract quality, diagnostic and therapeutic efficacy and safety, and the development of new vaccines based on the use of recombinant allergens.


Asunto(s)
Alérgenos/inmunología , Olea/inmunología , Polen/inmunología , Alérgenos/química , Alérgenos/genética , Humanos , Olea/genética , Olea/fisiología , Polen/citología , Polen/genética , Polen/fisiología , Polimorfismo Genético , Isoformas de Proteínas , Rinitis Alérgica Estacional/diagnóstico , Rinitis Alérgica Estacional/inmunología , Rinitis Alérgica Estacional/terapia , España
7.
J Investig Allergol Clin Immunol ; 17 Suppl 1: 41-7, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18050571

RESUMEN

BACKGROUND: English plantain (Plantago lanceolata L.) and olive (Olea europaea L.) pollens are important causes of pollinosis in large areas of North America, Australia, and the Mediterranean basin. The major pollen allergens of both plants, Pla I 1 and Ole e 1, share 38.7% of their amino acid sequences. OBJECTIVE: To analyze putative cross-reactivity between these 2 proteins. METHODS: Several antibodies and patients' sera were used in immunoblot and immunocytochemistry experiments. RESULTS: Two anti-Pla I 1 antibodies were able to bind to 3 polypeptides from olive pollen protein extracts, which correspond to the 3 glycosylation isoforms of Ole e 1 (18-22 kDa) previously described. Moreover, Pla I 1 protein was found in the cytoplasm of both the vegetative and the generative cells of P lanceolata mature pollen. On olive pollen sections, these anti-Pla I 1 antibodies displayed significant labeling in the cytoplasm of the vegetative cell and in both the exine and the material adhering to this outer layer of the pollen wall. In addition, the anti-Ole e 1 antibody 10H1 was found to cross-react with proteins of similar masses (16-20 kDa) to Pla I 1 variants. In Plantago pollen sections, the 10H1 antibody recognized proteins located in the cytoplasm of both the vegetative and generative cells. Cross-reaction was confirmed using sera from patients allergic to either plant pollen. CONCLUSION: Both allergens share common epitopes, which can be cross-recognized by different antibodies and sera from different patients, although this antigenic similarity seems to have little clinical relevance.


Asunto(s)
Alérgenos/inmunología , Glicoproteínas/inmunología , Olea/inmunología , Proteínas de Plantas/inmunología , Plantago/inmunología , Polen/inmunología , Alérgenos/análisis , Antígenos de Plantas , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática , Epítopos , Glicoproteínas/análisis , Humanos , Microscopía Electrónica de Transmisión , Olea/ultraestructura , Proteínas de Plantas/análisis , Plantago/ultraestructura , Polen/ultraestructura
8.
Biocell ; 27(1): 11-8, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12875246

RESUMEN

Cell wall pectins are some of the most complex biopolymers known, and yet their functions remain largely mysterious. The aim of this paper was to deepen the study of the spatial pattern of pectin distribution in the aperture of Oenothera hookeri.velans ster/+ster fertile pollen. We used "in situ" immunocytochemical techniques at electron microscopy, involving monoclonal antibodies JIM5 and JIM7 directed against pectin epitopes in fertile pollen grains of Oenothera hookeri.velans ster/+ster. The same region was also analyzed by classical cytochemistry for polysaccharide detection. Immunogold labelling at the JIM7 epitope showed only in mature pollen labelling mainly located at the intine endo-aperture region. Cytoplasmic structures near the plasma membrane of the vegetative cell showed no labelling gold grains. In the same pollen stge the labelling at the JIM5 epitope was mostly confined to a layer located in the limit between the endexine and the ektexine at the level of the border of the oncus. Some tubuli at the base of the ektexine showed also an accumulation of gold particles. No JIM5 label was demonstrated in the aperture chamber and either in any cytoplasmic structure of the pollen grains. The immunocytochemical technique, when compared with the traditional methods for non-cellulose polysaccharide cytochemistry is fare more sensitive and allows the univocal determination of temporal and spatial location of pectins recognized by the JIM7 and JIM5 MAbs.


Asunto(s)
Oenothera/metabolismo , Pectinas/metabolismo , Polen/metabolismo , Anticuerpos Monoclonales/metabolismo , Pared Celular/química , Pared Celular/metabolismo , Pared Celular/ultraestructura , Epítopos/metabolismo , Inmunohistoquímica , Oenothera/citología , Polen/ultraestructura , Polisacáridos/química , Polisacáridos/metabolismo , Sensibilidad y Especificidad , Factores de Tiempo , Distribución Tisular
9.
Protoplasma ; 221(3-4): 237-44, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12802631

RESUMEN

The presence of abundant oil bodies in the mature olive pollen grain has led us to focus on the behavior of these lipid bodies during pollen development and in vitro pollen germination. The appearance, increase, and accumulation of lipid bodies have been determined by following the sequential development of the pollen grain. Semithin slices of anthers and pollen grains were stained with Sudan Black B in order to identify neutral lipids. Ultrastructural studies were also carried out. Our results show a notable increase in lipid bodies between the young-pollen-grain stage and the mature-pollen-grain stage. Substantial polarization of lipid bodies was observed after 1 or 2 h of pollen incubation in germination medium. During pollen tube growth, the lipid bodies are located near the germinative aperture after 3 h of incubation, as well as inside the pollen tube, thus suggesting that the lipid bodies move from the pollen grain to the pollen tube. After 7 h of germination the presence of lipid bodies inside the pollen tube is no longer substantial. Our results support the idea that lipid bodies are involved in pollen germination, stigma penetration, and pollen tube growth. These results are discussed in connection with their implications for the pollen germination process.


Asunto(s)
Germinación , Metabolismo de los Lípidos , Olea/crecimiento & desarrollo , Olea/metabolismo , Polen/ultraestructura , Polaridad Celular , Técnicas In Vitro , Microscopía Electrónica , Microscopía de Polarización , Olea/citología , Factores de Tiempo
10.
Biocell ; 27(1): 11-18, Apr. 2003.
Artículo en Inglés | LILACS | ID: lil-384255

RESUMEN

Cell wall pectins are some of the most complex biopolymers known, and yet their functions remain largely mysterious. The aim of this paper was to deepen the study of the spatial pattern of pectin distribution in the aperture of Oenothera hookeri.velans ster/+ster fertile pollen. We used "in situ" immunocytochemical techniques at electron microscopy, involving monoclonal antibodies JIM5 and JIM7 directed against pectin epitopes in fertile pollen grains of Oenothera hookeri.velans ster/+ster. The same region was also analyzed by classical cytochemistry for polysaccharide detection. Immunogold labelling at the JIM7 epitope showed only in mature pollen labelling mainly located at the intine endo-aperture region. Cytoplasmic structures near the plasma membrane of the vegetative cell showed no labelling gold grains. In the same pollen stge the labelling at the JIM5 epitope was mostly confined to a layer located in the limit between the endexine and the ektexine at the level of the border of the oncus. Some tubuli at the base of the ektexine showed also an accumulation of gold particles. No JIM5 label was demonstrated in the aperture chamber and either in any cytoplasmic structure of the pollen grains. The immunocytochemical technique, when compared with the traditional methods for non-cellulose polysaccharide cytochemistry is fare more sensitive and allows the univocal determination of temporal and spatial location of pectins recognized by the JIM7 and JIM5 MAbs.


Asunto(s)
Oenothera/metabolismo , Pectinas/metabolismo , Polen/metabolismo , Anticuerpos Monoclonales/metabolismo , Epítopos/metabolismo , Inmunohistoquímica , Oenothera/citología , Pared Celular/química , Pared Celular/metabolismo , Pared Celular/ultraestructura , Polen/ultraestructura , Polisacáridos/química , Polisacáridos/metabolismo , Sensibilidad y Especificidad , Factores de Tiempo , Distribución Tisular
11.
Micron ; 33(1): 33-7, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-11473812

RESUMEN

In situ reverse transcription-PCR of mRNAs corresponding to the olive major allergen (Ole e I) has been tested at the ultrastructural level in mature olive pollen. The transcripts were present in the cytoplasm of both the vegetative and the generative cells, frequently associated to ribosomes in the endoplasmic reticulum. No labeling was detected in the pollen wall, nor in vacuoles, lipid bodies, plastids or mitochondria. Localization of the major olive allergen at ultrastructural level showed the protein present mainly in the lumen of the endoplasmic reticulum vesicles or pockets scattered in the cytoplasm, and in the outer region of the pollen exine. The results confirm the rough endoplasmic reticulum as the cell system involved in both the synthesis and storage of this protein. This is the first report of in situ RT-PCR on plant material at the ultrastructural level. The method described for mRNA amplification and detection is confirmed as a valuable tool for studying gene expression in plant material.


Asunto(s)
Alérgenos/genética , Magnoliopsida , Proteínas de Plantas/genética , Polen/química , ARN Mensajero/análisis , Alérgenos/metabolismo , Antígenos de Plantas , Inmunohistoquímica , Microscopía Electrónica , Proteínas de Plantas/metabolismo , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Árboles
12.
Planta ; 213(2): 182-91, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11469582

RESUMEN

Localization of pectins in the style of Petunia hybrida before and after pollination was investigated by immunocytochemistry using two primary monoclonal antibodies specific to highly (JIM7) and weakly (JIM5) methylesterified pectins. In the unpollinated style, esterified pectins occurred mainly in the cell walls of cortex tissue, while unesterified pectins were present mainly in the extracellular matrix (ECM) of the transmitting tract. After pollination no remarkable differences were found in pectin distribution in the ground tissue of the style. On the other hand, in the transmitting tract a reduction in the quantity of unesterified pectins was observed. Unesterified pectins in the extracellular regions of the transmitting tissue decreased before the penetration of the pollen tubes, indicating that pollination induces a reduction in the amount of unesterified pectins in the transmitting-tract ECM. The correlation between the degradation of strongly Ca2+-binding pectins and the growing level of those ions in the extracellular regions of the transmitting tract in the pollinated pistil of P. hybrida (M. Lenartowska et al. 1997) suggests that this process may constitute a mechanism for creating an optimum calcium medium for in vivo-growing pollen tubes. Both pectin categories were localized in pollen tubes. Esterified pectin epitopes were localized mainly in the vesicles of the tip cytoplasm. Unesterified pectin epitopes were found in the external fibrillar wall of pollen tubes.


Asunto(s)
Magnoliopsida/química , Pectinas/análisis , Anticuerpos Monoclonales , Calcio/metabolismo , Epítopos , Esterificación , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Magnoliopsida/citología , Magnoliopsida/crecimiento & desarrollo , Magnoliopsida/ultraestructura , Microscopía Electrónica , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/metabolismo , Polen/crecimiento & desarrollo , Polen/metabolismo
13.
Genomics ; 69(1): 95-103, 2000 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-11013079

RESUMEN

The genomic organization of the annexin A11 gene was determined in mouse and human to assess its congruity with other family members and to examine the species variation in alternative splicing patterns. Mouse annexin A11 genomic clones were characterized by restriction analysis, Southern blotting, and DNA sequencing, and the homologous human gene (HGMW-approved gene symbol ANXA11) was deciphered from high-throughput genomic sequence with coanalysis of expressed sequence tags. Exons 6-15 of the tetrad core repeat region differ from annexins A7 and A13 but are spliced identically to other phylogenetic descendents, making annexin A11 the putative primary progenitor of up to nine paralogous human annexins. The 5' regions consist of untranslated exon 1, followed by an extensive intron 1 comprising almost half the total gene length of >40 kb, and additional GC-rich exons 2-5 encoding the proline- and glycine-rich amino-terminus. Distinct cDNA isoforms in cow and human were determined to be unique to each species and hence of dubious general significance for this gene's function. Multiple transcription start sites were revealed by primer extension analysis of the mouse gene, and transfection constructs containing the prospective promoter generated transcriptional activity comparable to that of the SV40 promoter. Internal repetitive elements and vicinal gene markers were mapped for the complete human annexin A11 gene sequence to characterize the surrounding genomic environment.


Asunto(s)
Anexinas/genética , ADN Complementario/genética , Genes/genética , Células 3T3 , Empalme Alternativo , Animales , Secuencia de Bases , ADN/química , ADN/genética , ADN/aislamiento & purificación , ADN Complementario/química , Exones , Ligamiento Genético , Humanos , Intrones , Luciferasas/genética , Luciferasas/metabolismo , Ratones , Ratones Endogámicos , Datos de Secuencia Molecular , Regiones Promotoras Genéticas/genética , Isoformas de Proteínas/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Secuencias Repetitivas de Ácidos Nucleicos , Análisis de Secuencia de ADN , Transcripción Genética
14.
J Cell Sci ; 112 ( Pt 15): 2501-9, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10393806

RESUMEN

The distribution of Ole e I (the major olive pollen allergen) and its transcripts was investigated in the anther from premeiotic stages until the dehiscent pollen stage. Crude protein extracts were analyzed by immunoblotting and probed with a monoclonal antibody to Ole e I. The protein, with three variants, was found to accumulate from the early microspore stage onwards. In addition to the previously reported localization of the protein, Ole e I has been immunolocalized for the first time within the pollen wall and in the tapetum. Reverse transcription-polymerase chain reaction analysis using specific oligonucleotides and RNA extracted from whole anthers revealed that the Ole e I gene is expressed from the late tetrad stage onwards. No expression was found in control tissues such as petals, roots or leaves. Light microscopy in situ hybridization on developing flower buds and dehiscent pollen confirmed the transcripts to be present in both the microspores and the sporophytic tissue (tapetum). Labeling was found primarily in the tapetum, reaching the highest concentration in the cytoplasm of the developing and mature pollen, once tapetum started to degenerate. In situ hybridization at the transmission electron microscope level showed the transcripts to accumulate on ribosomes of the rough endoplasmic reticulum. These studies, together with others carried out previously by us, indicated that both synthesis and storage of Ole e I take place in the endoplasmic reticulum, coincidentally with the conspicuous changes suffered by this membrane system during pollen development. This process is most likely controlled at the transcriptional level. The localization of the protein in the pollen ectexine bring new insights into the function of the allergen, which are discussed.


Asunto(s)
Alérgenos/genética , Retículo Endoplásmico Rugoso/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Árboles/genética , Antígenos de Plantas , Retículo Endoplásmico Rugoso/ultraestructura , Regulación del Desarrollo de la Expresión Génica , Microscopía Inmunoelectrónica , Proteínas de Plantas/biosíntesis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción Genética , Árboles/crecimiento & desarrollo
15.
Biochem J ; 337 ( Pt 1): 125-31, 1999 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-9854034

RESUMEN

Mouse annexin V genomic clones were characterized by restriction analysis, Southern blotting and DNA sequencing. The entire gene spans close to 50 kb of the mouse genome and contains 14 exons ranging in size from 31 bp for exon 2 to 482 bp for exon 13 up to the polyadenylation site. Intron sizes range from 111 bp for intron 1b to more than 17 kb for intron 2. Non-coding exon 1 is present in two alternative forms separated by approx. 7.4 kb, and the two promoters associated with exons 1a and 1b are quite distinct. The upstream promoter has a TATA box and may direct the limited, tissue-specific expression of mRNA transcripts containing exon 1a. The downstream, TATA-less promoter has high G+C content, and exon 1b predominates among abundantly expressed mRNA species. The conservation of certain cis-elements, including Sp1, AP2, gamma-IRE and NF-IL6, in orthologous species of annexin V genes points to their possible role in trans-acting protein factor binding and gene regulation. Primer-extension analysis revealed multiple origins for transcription, with principal start sites 100-150 bp upstream of the ATG start codon in exon 2. Intron 4 was longer than that previously identified in the orthologous rat gene due to the integration of an apparently complete copy of the murine endogenous retrovirus element, MuERV-L. Phylogenetic analysis of annexin V from 12 species and the presence of neighbouring loci with paralogous counterparts linked to annexin VI pointed to the common ancestry of these genes via chromosomal duplication more than 600 million years ago.


Asunto(s)
Anexina A5/genética , Retrovirus Endógenos/genética , Genoma , Animales , Anexina A5/aislamiento & purificación , Secuencia de Bases , Clonación Molecular , ADN Viral , Ratones , Datos de Secuencia Molecular , Filogenia , Regiones Promotoras Genéticas , Ratas , Secuencias Repetitivas de Ácidos Nucleicos , Homología de Secuencia de Ácido Nucleico , Transcripción Genética
16.
Eur J Cell Biol ; 74(2): 181-9, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9352223

RESUMEN

We studied the ultrastructural evolution of the nucleolus during meiotic prophase in olive microsporocytes. During prophase, nuclear bodies morphologically similar to coiled bodies were observed. The nucleic acid composition of these bodies was examined in microsporocytes using electron microscopic techniques with EDTA preferential ribonucleoprotein staining, anti-DNA immunolabeling, the in situ terminal deoxynucleotidyl transferase-immunogold technique, and in situ hybridization with 18S rRNA and U3 snoRNA digoxigenin-labeled probes. The ultrastructural appearance of the meiocyte nucleolus indicated a low level of activity from the early prophase stage: the granular component was practically absent and nucleoli were constituted almost exclusively by dense fibrillar component containing large fibrillar centers that lacked chromatin inclusions. However, the appearance of reactivation vacuoles in the nucleolus during zygotene and high levels of rRNA in the nucleoplasm during pachytene support the presence of a peak in rRNA synthesis. Our results also show that the nuclear bodies that appear during prophase I are ribonucleoproteinaceous in nature; neither DNA nor ribosomal RNA were detected. The presence of U3 snoRNA, as shown by in situ hybridization in nuclear bodies from plant material, is also evidence that these structures are coiled bodies. We suggest that coiled bodies are involved not only in pre- and post-splicing events but also in the storage, transport or recycling of rRNA maturation elements.


Asunto(s)
Nucléolo Celular/metabolismo , Núcleo Celular/metabolismo , Meiosis , Profase/fisiología , Nucléolo Celular/química , Nucléolo Celular/ultraestructura , Núcleo Celular/química , Núcleo Celular/ultraestructura , ADN/análisis , Ácido Edético/metabolismo , Hibridación in Situ , Ácidos Nucleicos/análisis , Células Vegetales , Precursores del ARN/análisis , ARN Ribosómico 18S/análisis , ARN Nuclear Pequeño/análisis , Coloración y Etiquetado
17.
Biotech Histochem ; 72(6): 285-90, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9453673

RESUMEN

The callosic wall which covers microsporocyte mother cells during meiotic division has been studied using different fluorochromes as alternatives to the widely used aniline blue. We have confirmed that both acridine orange and 4', 6' diamidino-2-phenylindole (DAPI) produce a fluorescent response to callose which is comparable in specificity and intensity to that of aniline blue; therefore, they can be used to study callose wall formation. Staining properties of these fluorochromes, as well of those of curcumin and sirofluor, reported earlier as fluorescent stains for callose, are discussed. We also discuss the efficacy of the combined use of sirofluor and DAPI to study particular aspects of the deposition of callose.


Asunto(s)
Colorantes Fluorescentes , Glucanos/metabolismo , Células Vegetales , Plantas/metabolismo , Colorantes , Histocitoquímica , Fijación del Tejido
18.
Ann Rheum Dis ; 55(12): 895-900, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9014583

RESUMEN

OBJECTIVE: To investigate the occurrence of anti-annexin V autoantibodies in sera of patients with rheumatoid arthritis to assess involvement with the disease and any relation to glucocorticoid treatment. METHODS: Anti-annexin V antibodies were measured by an enzyme linked immunosorbent assay (ELISA) which used the purified human recombinant protein as antigen. RESULTS: Concentrations of anti-annexin V autoantibodies, predominantly of the IgG class, were significantly raised in sera from patients with rheumatoid arthritis compared to normal controls. This was not correlated with other indices of disease activity such as erythrocyte sedimentation rate or C reactive protein and was unrelated to glucocorticoid treatment. CONCLUSIONS: Extracellular annexin V provides an antigenic stimulus for autoantibody production and its in vivo expression is independent of glucocorticoid control. Such autoantibodies may have a detrimental role in the arthritic condition by interfering with putative functions of annexin V, including collagen type II binding, inhibition of phospholipase A2 activity, and Fc receptor activity.


Asunto(s)
Anexina A5/inmunología , Artritis Reumatoide/inmunología , Autoanticuerpos/sangre , Adulto , Anciano , Anexina A5/biosíntesis , Artritis Reumatoide/tratamiento farmacológico , Sedimentación Sanguínea , Proteína C-Reactiva/análisis , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/metabolismo , Femenino , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Prednisolona/uso terapéutico , Proteínas Recombinantes/biosíntesis
19.
J Cell Sci ; 109 ( Pt 4): 859-66, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8718677

RESUMEN

We related changes in the ultrastructural organization of the nucleoli with the results of quantitative in situ hybridizations to characterize rRNA metabolism during the development of microspore mother cells in the sugar beet anther (Beta vulgaris L.). In the course of meiotic prophase and early postmeiotic interphase the morphological characteristics of the nucleoli are typical of low or no transcriptional activity and a low rate of rRNA processing. However, we found evidence of an apparent increase in the relative numbers of 18 S rRNA transcripts in some stages of microsporogenesis. This was found in both the nucleoli and cytoplasm of pachytene meiocytes, and in later stages there was a spectacular accumulation of rRNA transcripts in nucleoli of the tetrad cells. Quantitative data are analyzed in the light of morphometric findings in the cell and their compartments to elucidate the degree to which changes in cell size are related to changes in labeling density and distribution. The results are discussed in terms of rRNA synthesis, transport and degradation as processes involved in the regulation of rRNA within microsporocytes and microspores.


Asunto(s)
ADN de Plantas/metabolismo , Plantas/genética , ARN Ribosómico 18S/metabolismo , Nucléolo Celular/ultraestructura , Hibridación in Situ , Microscopía Electrónica , Desarrollo de la Planta , Plantas/ultraestructura , Transcripción Genética
20.
J Histochem Cytochem ; 44(2): 151-8, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8609371

RESUMEN

We investigated the immunolocalization of the olive major allergen Ole e I and Ole e I-like proteins in pollen from several Oleaceae species [olive (Olea europaea), ash (Fraxinus excelsior), privet (Ligustrum vulgaris), lilac (Syringa vulgare), and forsythia (Forsythia suspensa)]. Crossreactions among different pollens were found in enzyme immunoassays. For immunolocalization with light microscopy we used the silver enhancement technique with three monoclonal antibodies (1D8, 10H1, and 16G2) that recognize three different epitopes of the allergen Ole e I. Our findings show that the silver enhancement technique is very useful when several antibodies are to be used for rapid screening of different materials. MAb 10H1 gave the most precise results and was selected for further immunolocalization studies with transmission electron microscopy. The epitope recognized by this MAb was localized exclusively in the endoplasmic reticulum in olive pollen. In lilac, privet, and ash pollen, most of the reactivity was also seen in the endoplasmic reticulum; however, the 10H1 epitope was not detected in forsythia pollen.


Asunto(s)
Alérgenos/análisis , Proteínas de Plantas/análisis , Plantas Medicinales/inmunología , Polen/inmunología , Alérgenos/inmunología , Animales , Antígenos de Plantas , Inmunohistoquímica , Microscopía Fluorescente , Microscopía Inmunoelectrónica , Proteínas de Plantas/inmunología , Conejos
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