Search

Fil: Podio, Maricel. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Fil: Podio, Maricel. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias, Argentina. Fil. Rodríguez, María Pía. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias, Argentina. Fil: Felitti, Silvina Andrea. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias, Argentina. Fil: Stein, Juliana. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias, Argentina. Fil: Martínez, Eric J. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Fil: Siena, Lorena Adelina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias, Argentina. Fil: Quarin, Camilo Luis. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Fil: Pessino, Silvina Claudia. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias, Argentina. Fil: Ortíz, Juan Pablo Amelio. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias, Argentina. In previous studies we reported the identification of several AFLP, RAPD and RFLP molecular markers linked to apospory in Paspalum notatum. The objective of this work was to sequence these markers, obtain their flanking regions by chromosome walking and perform an in silico mapping analysis in rice and maize. The methylation status of two apospory-related sequences was also assessed using methylation-sensitive RFLP experiments. Fourteen molecular markers were analyzed and several protein-coding sequences were identified. Copy number estimates and RFLP linkage analysis showed that the sequence PnMAI3 displayed 2-4 copies per genome and linkage to apospory. Extension of this marker by chromosome walking revealed an additional protein-coding sequence mapping in silico in the apospory-syntenic regions of rice and maize. Approximately 5 kb corresponding to different markers were characterized through the global sequencing procedure. A more refined analysis based on sequence information indicated synteny with segments of chromosomes 2 and 12 of rice and chromosomes 3 and 5 of maize. Two loci associated with apomixis locus were tested in methylation-sensitive RFLP experiments using genomic DNA extracted from leaves. Although both target sequences were methylated no methylation polymorphisms associated with the mode of reproduction were detected.

Grubbs, Scott A., Pessino, Massimo, DeWalt, R. Edward (2012): Michigan Plecoptera (Stoneflies): Distribution Patterns And An Updated Species List. Illiesia 8 (18): 162-173, DOI: http://doi.org/10.5281/zenodo.4753235, {"references":["Baumann, R.W. 1996. A review of the stonefly genus Paranemoura (Plecoptera: Nemouridae) and a new species from the northeast. Proceedings of the Entomological Society of Washington, 98:818-826.","Boumans, L. & R.W. Baumann. 2012. Amphinemura palmeni is a valid Holarctic stonefly genus (Plecoptera: Nemouridae). Zootaxa, 3537:59-75.","Bright, E. 1996. A new larval record of Perlinella drymo (Plecoptera: Perlidae) for Michigan. The Great Lakes Entomologist, 29:39-42.","DeWalt, R.E. & S.A. Grubbs. 2011. Updates to the stonefly fauna of Illinois and Indiana. Illiesia, 7:31-50.","DeWalt, R.E., C. Favret, & D.W. Webb. 2005. Just how imperiled are aquatic insects? A case study of stoneflies (Plecoptera) in Illinois. Annals of the Entomological Society of America, 98:941-950.","DeWalt R.E., U. Neu-Becker, & G. Steuber. 2012. Plecoptera species file online. Version 1.0/4.1 [18 September 2012]. Available online, http://Plecoptera.SpeciesFile.org","DeWalt, R.E., Y. Cao, T. Tweddale, S.A. Grubbs, L. Hinz, & M. Pessino. 2012. Ohio USA stoneflies (Insecta: Plecoptera): species richness estimation, distribution of functional niche traits, drainage affiliations, and relationship to other state faunas. ZooKeys, 178:1-26.","Frison, T.H. 1942. Studies on North American Plecoptera, with special reference to the fauna of Illinois. Bulletin of the Illinois Natural History Survey, 22:235-355.","Grubbs, S.A. 1997. New records, zoogeographic notes, and a revised checklist of stoneflies (Plecoptera) from Maryland. Transactions of the American Entomological Society, 123:71-84.","Grubbs, S.A. & E. Bright. 2001. Arcynopteryx compacta (Plecoptera: Perlodidae), a Holarctic stonefly confirmed from Lake Superior, with a review and first checklist of the stoneflies of Michigan. Great Lakes Entomologist, 34:77-84.","Grubbs, S.A. & R.E. DeWalt. 2012. Perlesta ephelida (Plecoptera: Perlidae), a new eastern Nearctic stonefly species. ZooKeys, 194:1-15.","Grubbs, S.A. & B.P. Stark. 2001. Notes on Perlesta (Plecoptera: Perlidae) from eastern North America. Aquatic Insects, 23:119-122.","Hanson, J.F. 1943. Records and descriptions of North American Plecoptera. Part III. Notes on Isogenoides. American Midland Naturalist, 29:657- 669.","Kondratieff, B.C. & R.F. Kirchner. 1987. Additions, taxonomic corrections, and faunal affinities of the stoneflies (Plecoptera) of Virginia, U.S.A. Proceedings of the Entomological Society of Washington, 89:24-30.","Needham, J.G. & P.W. Claassen. 1925. A monograph of the Plecoptera or stoneflies of America north of Mexico. Thomas Say Foundation Series, Entomological Society of America, 2:1-397.","Nelson, C.R. & R.W. Baumann. 1987. The winter stonefly genus Capnura (Plecoptera: Capniidae) in North America: systematics, phylogeny, and zoogeography. Transactions of the American Entomological Society, 113:1-28.","Nelson, C.R. & R.W. Baumann. 1989. Systematics and distribution of the winter stonefly genus Capnia (Plecoptera: Capniidae) in North America. Great Basin Naturalist, 49:289-363.","Poulton, B.C. & K.W. Stewart. 1991. The stoneflies of the Ozark and Ouachita Mountains (Plecoptera). Memoirs of the American Entomological Society, 38:1-116.","Ricker, W.E. 1952. Systematic studies of Plecoptera. Indiana University Publication Scientific Series, 18:1-200.","Sandberg, J.B. & K.W. Stewart. 2005. Holomorphology and systematic of the stonefly genus Isogenoides (Plecoptera: Perlodidae). Transactions of the American Entomological Society, 131:269-345.","Stark, B.P. 2004. Perlidae (The Stones). Pages 61-148. In B.P. Stark & B.J. Armitage, editors. The Stoneflies (Plecoptera) of Eastern North America. Volume II. Chloroperlidae, Perlidae, and Perlodidae (Perlodinae). Bulletin of the Ohio Biological Survey, New Series Volume 14, Columbus, Ohio. 192 pp.","Stark, B.P. & R.W. Baumann. 2004. The winter stonefly genus Paracapnia (Plecoptera: Capniidae). Monographs of the Western North American Naturalist, 2:96-108.","Stewart, K.W. & B.P. Stark. 2002. Nymphs of North American Stonefly Genera (Plecoptera), 2nd edition. The Caddis Press, Columbus, Ohio, 510 pp.","Stout, R.J. & M.P. Rondinelli. 1995. Stream-dwelling insects and extremely low frequency electromagnetic fields: a ten year study. Hydrobiologia, 302:197-213.","Surdick, R.F. 2004. Chloroperlidae (The Sallflies). Pages 1-60. In B.P. Stark & B.J. Armitage, editors. The Stoneflies (Plecoptera) of Eastern North America. Volume II. Chloroperlidae, Perlidae, and Perlodidae (Perlodinae). Bulletin of the Ohio Biological Survey, New Series Volume 14, Columbus, Ohio. 192 pp.","Teslenko, V.A. 2012. A taxonomic revision of the genus Arcynopteryx Klapalek, 1904 (Plecoptera, Perlodidae). Zootaxa, 3329:1-18.","Yanoviak, S.P. & W.P. McCafferty. 1996. Comparison of macroinvertebrate assemblages inhabiting pristine streams in the Huron Mountains of Michigan, U.S.A. Hydrobiologia, 330:195-211."]}

A genomic clone encoding ferredoxin-NADP reductase binding protein (BP) from Zea mays L. was sequenced and characterized. The promoter region (692 bp) shows several motives resembling those involved in enhancement, tissue-specific expression and light regulation in plants, besides the typical TATA and CAAT boxes. The coding sequence is interrupted by two introns. The deduced amino acid (aa) sequence corresponds to 22.85 kDa for the precursor polypeptide, including a transit peptide of 64 aa and a mature protein of 148 aa.

This book reports on the status and evolution of human opportunity in Latin America and the Caribbean (LAC). It builds on the 2008 publication in several directions. First, it uses newly available data to expand the set of opportunities and personal circumstances under analysis. The data are representative of about 200 million children living in 19 countries over the last 15 years. Second, it compares human opportunity in LAC with that of developed countries, among them the United States and France, two very different models of social policy. This allows for illuminating exercises in benchmarking and extrapolation. Third, it looks at human opportunity within countries, across regions, states, and cities. This gives us a preliminary glimpse at the geographic dimension of equity, and at the role that different federal structures play. The overall message that emerges is one of cautious hope. LAC is making progress in opening the doors of development to all, but it still has a long way to go. At the current pace, it would take, on average, a generation for the region to achieve universal access to just the basic services that make for human opportunity. Seen from the viewpoint of equity, even our most successful nations lag far behind the developed world, and intracounty regional disparities are large and barely converging. Fortunately, there is much policy makers can do about it.

Conventional wisdom states that fiscal policy redistributes little in Latin America. Lower tax revenues and, above all, lower and less progressive transfers have been identified as the main cause. Existing studies show that, while in Europe the distribution of all transfers combined (cash and in-kind) is egalitarian, the bulk of transfers in Latin America accrue to the upper quintile. Through an in-depth fiscal incidence analysis applied to Argentina, Bolivia, Brazil, Mexico and Peru we argue that conventional wisdom may be wrong. First, the extent and effectiveness of income redistribution and poverty reduction, revenue-collection, and spending patterns vary so significantly across countries that speaking of "Latin America" as a unity is misleading. The (after direct taxes and transfers) Gini, for example, declines by over 10 percent in Argentina but by only 2.4 percent in Bolivia. In Argentina, Brazil and Bolivia government revenues are close to 40 percent of GDP, whereas in Mexico and Peru they are around 20 percent. Social spending (excluding contributory pensions) as a share of GDP ranges from 17 percent in Brazil to 5.2 percent in Peru. Second, social spending does not accrue to the richest quintile. On the contrary, concentration coefficients for social spending are highly negative (progressive in absolute terms) for Argentina and slightly so for Bolivia and Mexico. In Brazil and Peru social spending is progressive in relative terms only. Third, there is no obvious correlation between the size of government and the size of social spending, on the one hand, and the extent and effectiveness of redistribution, on the other: government size is similar for Argentina and Bolivia but they are on opposite sides in terms of the extent of redistribution.Fourth, due to indirect taxes households are net payers to the "fisc" beginning in the third decile in Bolivia and Brazil; for Argentina, Mexico and Peru this happens in the fifth decile. Fifth, corrective measures differ too: in Argentina, Bolivia and Brazil they may involve the reduction in revenues and total spending, while revenues and social spending (especially direct transfers to the poor) should be increased in Mexico and Peru. Bolivia and Brazil need to introduce changes to their tax and transfer system so that net payers to the "fisc" start at higher incomes. All five countries need to improve the of progressivity of their spending, including non-social spending components.

Weeping lovegrass is a forage grass cultivated in semiarid regions of the world that reproduces mainly by apomixis (diplospory), a process that involves the formation of asexual seeds and bypasses the processes of meiosis and fertilisation. The aim of this work was to evaluate and compare different techniques (cytoembryology, callose deposition, flow cytometry and progeny tests) to determine the reproductive mode of weeping lovegrass. Typical sexual and apomictic processes were clearly differentiated using cytoembryology, and different callose deposition patterns were observed in sexual and apomictic genotypes. Previous studies indicated that presence of callose on the cell wall of the megaspore mother cell is associated only with sexual processes. Nevertheless, our results also found callose deposition in apomictic genotypes, although clearly different from the pattern found in sexual processes, allowing discrimination between sexual and apomictic plants. Flow cytometry seed screening using individual seeds did not differentiate between sexual and apomictic plants as the embryo : endosperm DNA content ratio was similar in sexual and apomictic plants. Progeny tests using molecular markers showed uniform patterns in offspring from apomictic plants and variable patterns among the progeny of sexual plants. The results obtained from cytological studies and progeny tests were similar, indicating that both methods provide useful tools for determination of reproductive mode. However, the callose test with aniline blue was faster and easier to use than other techniques. Fil: Meier, Mauro Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentina Fil: Zappacosta, Diego Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentina Fil: Selva, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentina Fil: Pessino, Silvina Claudia. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Echenique, Carmen Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentina

Este trabajo es parte de una serie de estudios realizados en el marco del proyecto: “La efectividad de las redes de protección social: El rol de los sistemas integrados de información social”. Los estudios de caso fueron realizados en el período 2007-08. Se agradecen los comentarios de Ignacio Irarrázaval y Viviane Azevedo.

On the basis of the amino acid sequence of isolated tryptic peptides, it has been established that the differentiation enhancing factor, produced and active on murine erythroleukemia (MEL)cells, possesses a unique sequence, with no similarity to that of known proteins. Accordingly, this factor can be defined as a novel biologically active peptide. An antisense oligodeoxynucleotide, deduced from the sequence of a nonadecapeptide (produced by tryptic digestion of the factor), decreases the rate and the extent of MEL cell differentiation, induced by hexamethylenebisacetamide. In these cells the amount of the factor is reduced to one third of that constitutively present in untreated cells. Exogenous addition of the factor restores cell inducibility to normal values. Taken together, these results demonstrate the presence in MEL cells of a new factor, structurally and firnctionally unrelated to any of the known biologically active peptides, and suggest its crucial role in the promotion of an initial signal, in chemically induced erythroid differentiation.

Several studies have demonstrated that the intrinsic catalytic activity of cell surface glucose transporters is highly regulated in 3T3-L1 adipocytes expressing GLUT1 (erythrocyte/brain) and GLUT4 (adipocyte/skeletal muscle) glucose transporter isoforms. For example, inhibition of protein synthesis in these cells by anisomycin or cycloheximide leads to marked increases in hexose transport without a change in the levels of cell surface glucose transporter proteins (Clancy, B. M., Harrison, S. A., Buxton, J. M., and Czech, M. P. (1991) J. Biol. Chem. 266, 10122-10130). In the present work the exofacial hexose binding sites on GLUT1 and GLUT4 in anisomycin-treated 3T3-L1 adipocytes were labeled with the cell-impermeant photoaffinity reagent [2-3H]2-N-[4-(1-azitrifluoroethyl)benzoyl]-1,3-bis- (D-mannos-4-yloxy)-2-propylamine [( 2-3H] ATB-BMPA) to determine which isoform is activated by protein synthetic blockade. As expected, a 15-fold increase in 2-deoxyglucose uptake in response to insulin was associated with 1.7- and 2.6-fold elevations in plasma membrane GLUT1 and GLUT4 protein levels, respectively. Anisomycin treatment of cultured adipocytes for 5 h produced an 8-fold stimulation of hexose transport but no increase in the content of glucose transporters in the plasma membrane fraction as measured by protein immunoblot analysis. Cell surface GLUT1 levels were also shown to be unaffected on 3T3-L1 adipocytes in response to anisomycin using an independent method, the binding of an antiexofacial GLUT1 antibody to intact cells. In contrast, anisomycin fully mimicked the action of insulin to stimulate (about 4-fold) the radiolabeling of GLUT1 transporters specifically immunoprecipitated from intact 3T3-L1 adipocytes irradiated after incubation with [2-3H] ATB-BMPA. Photolabeling of GLUT4 under these conditions was also significantly enhanced (1.8-fold) by anisomycin treatment, but this effect was only 15% of that caused by insulin. These results suggest that: 1) the photoaffinity reagent [2-3H]ATB-BMPA labels those cell surface glucose transporters present in a catalytically active state rather than total cell surface transporters as assumed previously and 2) inhibition of protein synthesis in 3T3-L1 adipocytes stimulates sugar transport primarily by enhancing the intrinsic catalytic activity of cell surface GLUT1, and to a lesser extent, GLUT4 proteins.

In this study we tested the hypothesis that functional erythrocyte-type glucose transporters (GLUT1) exist as oligomeric complexes by expressing chimeric transporter proteins in Chinese hamster ovary cells harboring endogenous GLUT1 transporters. The chimeric transporters were GLUT1-4c, in which the 29 C-terminal residues of human GLUT1 were replaced by the 30 C-terminal residues of rat skeletal muscle glucose transporter (GLUT4), and GLUT1n-4, containing the N-terminal 199 residues of GLUT1 and the 294 C-terminal residues of GLUT4. Endogenous GLUT1 was quantitatively co-immunoprecipitated by using an anti-GLUT4 C-terminal peptide antibody from detergent extracts of Chinese hamster ovary cells expressing either of the chimeric proteins, as detected by immunoblotting the precipitates with an anti-GLUT1 C-terminal peptide antiserum. No co-immunoprecipitation of native GLUT1 with native GLUT4 from extracts of 3T3-L1 adipocytes, which contain both these transporters, was observed with the same antibody. These data are consistent with the hypothesis that GLUT1 transporters exist as homodimers or higher order oligomers and that a major determinant of oligomerization is located within the first 199 residues of GLUT1.

In many species polyploidization involves rearrangements of the progenitor genomes, at both genetic and epigenetic levels. We analyzed the cytosine methylation status in a ‘tetraploid-diploid-tetraploid’ series of Eragrostis curvula with a common genetic background by using the MSAP (Methylation-sensitive Amplified Polymorphism) technique. Considerable levels of polymorphisms were detected during ploidy conversions. The total level of methylation observed was lower in the diploid genotype compared to the tetraploid ones. A significant proportion of the epigenetic modifications occurring during the tetraploid–diploid conversion reverted during the diploid–tetraploid one. Genetic and expression data from previous work were used to analyze correlation with methylation variation. All genetic, epigenetic and gene expression variation data correlated significantly when compared by pairs in simple Mantel tests. Dendrograms reflecting genetic, epigenetic and expression distances as well as principal coordinate analysis suggested that plants of identical ploidy levels present similar sets of data. Twelve (12) different genomic fragments displaying different methylation behavior during the ploidy conversions were isolated, sequenced and characterized.

This paper presents the rationale in theory and practical implementation of a system for identification and exchanging information. This system allows governments to confront the problem of informality, tax evasion and social expenditure jointly, with important economies of scale, because the data or some personal information can be optimally used for both objectives increasing social benefits while decreasing costs.This system is about e-government inside the government itself. Hence it is concerned with E-management --- the use of information technology to improve the management of government, from streamlining business processes to maintaining electronic records, to improving the flow and integration of information.

Paspalum notatum Flugge is a warm-season forage grass with mainly diploid (2n =20) and autotetraploid (2n = 40) representa-tives.Diploid races reproduce sexually andrequire crosspollination due to a self-incom-patible mating system, while autotetraploids reproduce by aposporous apomixis. The objec-tives of this work were to develop a genetic linkage map of Paspalum notatum Flugge at the tetraploid level, identify the linkage/s group/s associated with apomixis and carry out a general characterization of its mode of inheritance. A pseudo test-cross F1 family of 113 individuals segregating for the mode of reproduction was obtained by crossinga syn-thetic completely sexual tetraploid plant (Q4188) as female parent with a naturalaposporous individual (Q4117) as pollen donor.Map construction was based on single-dose markers (SDAFs) segregating from both par-ents. Two linkage maps (female and male) were constructed. Within each map, homolo-gous groups were assembled by detectingrepulsion-phase linked SDAFs. Putative Q4188 and Q4117 homolog groups were identified by mapping shared single dose mark-ers (BSDF). The Q4188 map consisted of 263 markers distributed on 26 co-segregation groups over a total genetic distance of 1.590.6 cM, while the Q4117 map contained 216 loci dispersed on 39 co-segregation groups along 2.265.7 cM, giving an estimated genome cov-erage of 88% and 83%, respectively. Seven and 12 putative homologous chromosomes were detected within Q4188 and Q4117 maps,respectively. Afterward, ten female and male homologous chromosomes were identified by mapping BSDFs. In the Q4117 map, a single linkage group was associated with apospory. It was characterized by restriction in recombina-tion and preferential chromosome pairing. A BPSD marker mapping within this group allowed the detection of the female homolog and the putative four male groups of the set carrying apospory. Fil: Stein, Juliana. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Laboratorio de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pessino, Silvina Claudia. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Laboratorio de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Martínez, Eric Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Rodriguez Romero, María Pía. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Laboratorio de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Siena, Lorena Adelina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Laboratorio de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Quarin, Camilo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Ortiz, Juan Pablo Amelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Apomixis is a route of asexual reproduction through seeds, that progresses in the absence of meiosis and fertilization to generate maternal clonal progenies. Gametophytic apomicts are usually polyploid and probably arose from sexual ancestors through a limited number of mutations in the female reproductive pathway. A differential display analysis was carried out on immature inflorescences of sexual and apomictic tetraploid genotypes of Paspalum notatum, in order to identify genes associated with the emergence of apospory. Analysis of approximately 10,000 transcripts led to the identification of 94 high-quality differentially expressed sequences. Assembling analysis, plus validation, rendered 65 candidate unigenes, organized as 14 contigs and 51 singletons. Thirty-four unigenes were isolated from apomictic plants and 31 from sexual ones. A total of 45 (69.2%) unigenes were functionally categorized. While several of the differentially expressed sequences appeared to be components of an extracellular receptor kinase (ERK) signal transduction cascade, others seemed to participate in a variety of central cellular processes like cell-cycle control, protein turnover, intercellular signalling, transposon activity, transcriptional regulation and endoplasmic reticulum-mediated biosynthesis. In silico mapping revealed that a particular group of five genes silenced in apomictic plants clustered in a rice genomic area syntenic with the region governing apospory in Paspalum notatum and Brachiaria brizantha. Two of these genes mapped within the set of apo-homologues in P. notatum. Four genes previously reported to be controlled by ploidy were identified among those expressed differentially between apomictic and sexual plants. In situ hybridization experiments were performed for selected clones.

Feeding habits of Perla grandis (Rambur) nymphs have been investigated in the Rio Berga, an Apenninic stream of Northwestern Italy. In this study, we analysed gut contents of 50 nymphs of this species, with the aim to investigate feeding preferences. Nymphs were collected from a single riffl e, of which benthic coenosis was also determined. We detected a change in the diet during ontogenesis, with small instars feeding mainly on detritus and large instars strictly carnivorous. We also detected the existence of an evident trophic selection: diet was almost entirely dominated by Chironomidae, independently from their availability on the substratum. This fi nding is discussed on the basis of ecological and ethological considerations. Resume. Alimentation des nymphes de Perla grandis (Plecoptera : Perlidae) dans une riviere de premier ordre des Apennins (Rio Berga, Nord-Ouest de l'Italie). Les habitudes alimentaires des nymphes de Perla grandis (Rambur) ont ete etudiees dans le Rio Berga, une riviere des Apennins du Nord-Ouest de l'Italie. Dans cette etude, nous avons analyse le contenu digestif de 50 nymphes de cette espece, dans le but de determiner leurs preferences alimentaires. Les nymphes ont ete collectees d'un seul rapide dont la cenose benthique a aussi ete identifi ee. Nous avons detecte un changement dans la diete au cours de l'ontogenese : les premiers stades se nourrissent surtout de detritus et les derniers stades deviennent strcitement carnivores. Nous avons aussi detecte l'existence d'une selection trophique manifeste : la diete est presque entierement dominee par les Chironomidae, independemment de leur disponibilite sur le substrat. Cette decouverte est discutee sur la base de considerations ecologiques et ethologiques.

For over 40 years, fluorouracil has been the only drug registered for the treatment of metastatic colorectal cancer. During the past 5 years, combination chemotherapy regimens including either irinotecan or oxaliplatin have proven to be superior to fluorouracil monotherapy in randomized clinical trials, in terms of response rate, progression-free survival and overall survival. Both doublets demonstrated similar efficacy, therefore either combination can be considered standard first-line treatment for metastatic colorectal cancer. Recently, a new orally active fluorouracil analog, capecitabine, and two targeted biological agents, cetuximab and bevacizumab, have been added to the armamentarium of drugs active against metastatic colorectal cancer, thus making the scenario more complex. Moreover, ongoing clinical trials are currently testing new promising molecularly targeted agents. Thus, we are facing a new era in which the rapid clinical development of novel agents is outpacing the ability to perform Phase III clinical trials. At present, there is no single standard treatment suitable for all patients. However, general principles of management can be derived from the available clinical data in order to guide the therapeutic choice and individualize treatment.

Although the causes of novel variation in polyploids are not well understood, they could involve changes in gene expression through dosage-regulation, altered regulatory interactions and rapid genetic/epigenetic changes. The objective of this work was to contribute to the elucidation of the patterns and mechanisms of gene regulation during the early stages of polyploid formation. The genome-wide expression of ∼10,000 genes was monitored by using differential display transcript profiling on flowers of a diploid genotype and a newly-formed autotetraploid derivative. Differential expression of 64 clones was validated by reverse-Northern blot. Sequence analysis showed that 42 were homologous to 26 distinct genes of known function while the remaining 22 were classified as novel sequences. Genes detected were involved in processes of DNA repair, chromatin structure modification, regulation of transcription, proteolysis, protein folding, carbohydrate and lipid metabolism and signal transduction. Our results show evidence for gene expression alterations occurring immediately after polyploidization in Paspalum Fil: Martelotto, Luciano G.. Universidad Catolica de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ortiz, Juan Pablo Amelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina Fil: Stein, Juliana. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Espinoza, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Quarin, Camilo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Pessino, Silvina Claudia. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The objective of this work was to determine the type of inheritance (disomic/polysomic) in tetraploid (2n=4x=40) Paspalum notatum and investigate the transmission pattern of the chromosome region associated with apospory. An F1 family segregating for the reproductive mode (aposporous vs non-aposporous) was generated by crossing a tetraploid sexual plant as female parent with an apomictic individual as pollen donor. Pollen mother cells from both parental plants were examined to ascertain chromosome-pairing behavior at meiosis. The high rate of quadrivalent chromosome associations indicated an autotetraploid origin of the species, although bivalent pairing and occasional univalents were detected. The observation of a lagging bivalent, a bridge of chromatin, or two aligned laggards in the aposporous parent suggested a chromosome inversion in this strain. Segregation ratios of AFLP markers and the proportion of linkages in repulsion versus coupling phase denoted tetrasomic inheritance, but markers displaying disomic ratios were also observed. Preferential chromosome pairing (disomic inheritance) in the chromosome segment related to apospory was detected. The possible relationship between a chromosome rearrangement and the inheritance of apospory is discussed. Fil: Stein, Juliana. Universidad Nacional de Rosario; Argentina Fil: Quarin, Camilo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Martínez, Eric Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Pessino, Silvina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentina Fil: Ortiz, Juan Pablo Amelio. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Progeny tests employing molecular markers allow the identification of individuals originated by sexual means among the offspring of a facultative apomict. The objective of this work was to evaluate the effect of the pollination timing on the proportion of sexually formed individuals in progenies of a facultative apomictic Paspalum notatum genotype. Progeny families of approx. 30 plants each were generated at five different pollination times: 1–3 d pre‐anthesis; at anthesis; and 2, 4 and 6 d post‐anthesis. Cytoembryological analyses indicated that approx. 17 % of the ovules carried a meiotic cytologically reduced embryo sac in florets formed simultaneously with those used for crosses. The parental plants and the five F1 families were analysed using RAPD molecular markers. Ninety‐five oligonucleotides were assayed on the progenitors in order to search for male‐specific bands. Eight primers presenting clear polymorphic bands were selected for use in the progeny tests. The proportion of sexually produced progeny reached 3·4 % before anthesis and 20 % at anthesis, while pollination after anthesis generated only maternal plants. A second progeny of 97 plants obtained from pollination at anthesis produced 16 off‐type plants (16·5 %), of which only one was a BIII hybrid (2n + n). Our results indicate that pollination at anthesis allows the greatest potential for sexuality to be expressed in this facultative apomictic genotype. When pollination is delayed as soon as 2 d after anthesis, only the aposporous sacs develop endosperm through pseudogamy to set seed. Fil: Espinoza, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Pessino, Silvina Claudia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Quarin, Camilo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Valle, Estela Marta. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

El presente trabajo tuvo como objetivo examinar la dieta del puma (Puma concolor) en el área del Parque Nacional Lihue Calel, durante los períodos 1994.1997 y 2000. La muestra analizada consistió en 198 heces a partir de las cuales se identificaron 244 individuos presa, resultando el 97% mamíferos, el 2% aves y el 1% reptiles. En términos de biomasa relativa las grandes presas (> 20 kg) representaron el 40.6%, las presas medianas (1-20 kg) el 59.1% y las presas pequeñas (< 1 kg) el 0.3%. Entre 1994 y 1996 las vizcachas (Lagostomus maximus) fueron la principal presa del puma, a pesar de estar sufriendo una disminución de sus poblaciones. Este proceso quedó evidenciado en la dieta por una notable reducción y la posterior desaparición de esta presa. Paralelamente se incrementó el consumo de otras presas medianas, especialmente armadillos (Chaetophractus villosus y Zaedyus pichiy) y ungulados (Sus scrofa y Lama guanicoe). Durante el período de estudio los valores de amplitudes de nicho trófico y peso promedio de presas fueron, en general, superiores a los registrados para el área en trabajos previos. We examined puma (Puma concolor) food habits between 1994.1997 and 2000 in Lihue Calel National Park area. Using fecal analysis we identified 244 prey items in 198 feces. Mammalian species accounted for 97% of all prey items, birds 2% and reptiles 1%. In terms of relative biomass, large preys (> 20 kg) made up 40.6% of the diet, medium preys (1-20 kg) 59.1% and small preys (< 1 kg) 0.3%. From 1994 to 1996 plains vizcachas (Lagostomus maximus) were the staple prey of pumas, even though they were declining. This process was evidenced in the reduction and subsequent disappearance of vizcachas in pumas diet. Parallelly, there was an increase of other medium-sized preys, especially armadillos (Chaetophractus villosus and Zaedyus pichiy), and ungulates (Sus scrofa and Lama guanicoe). During the study period, both the breadth of diet and the mean weight of vertebrate prey were generally higher than those recorded during previous studies in the same area.

Surface receptors involved in natural killer (NK) cell triggering during the process of tumor cell lysis have recently been identified. Of these receptors, NKp44 is selectively expressed by IL-2– activated NK cells and may contribute to the increased efficiency of activated NK cells to mediate tumor cell lysis. Here we describe the molecular cloning of NKp44. Analysis of the cloned cDNA indicated that NKp44 is a novel transmembrane glycoprotein belonging to the Immunoglobulin superfamily characterized by a single extracellular V-type domain. The charged amino acid lysine in the transmembrane region may be involved in the association of NKp44 with the signal transducing molecule killer activating receptor–associated polypeptide (KARAP)/DAP12. These molecules were found to be crucial for the surface expression of NKp44. In agreement with data of NKp44 surface expression, the NKp44 transcripts were strictly confined to activated NK cells and to a minor subset of TCR-γ/δ+ T lymphocytes. Unlike genes coding for other receptors involved in NK cell triggering or inhibition, the NKp44 gene is on human chromosome 6.

The NKp46 molecule has been proposed to play the role of triggering receptor in the natural cytotoxicity mediated by human NK cells. In this study we have identified the gene encoding the murine NKp46 homologue that we termed MAR-1. The MAR-1 gene is localized on chromosome 7 that is synthenic to the human chromosome 19 where the NKp46 gene is located. MAR-1 encodes a type I transmembrane glycoprotein belonging to the immunoglobulin (Ig) superfamily that, like human NKp46, is characterized by two C2-type Ig-like domains, a transmembrane portion containing a positively charged residue and a cytoplasmic tail lacking the immunoreceptor tyrosine-based activation motif (ITAM). The MAR-1 protein is expressed on the surface of cell transfectants and displays a molecular mass of approximately 46 kDa similar to that of its human counterpart. Semiquantitative RT-PCR analysis showed that MAR-1, similar to the human NKp46, is selectively expressed by NK cells. The MAR-1 protein displays 58 % identity with the human NKp46 receptor. This high homology together with the presence of a charged amino acid (Arg) in the transmembrane portion suggest that MAR-1 may associate at the cell membrane into a multimeric complex with ITAM containing polypeptides.

NK cells display several killer inhibitory receptors (KIRs) specific for different alleles of major histocompatibility complex (MHC) class I molecules. A family of KIRs are represented by type I transmembrane proteins belonging to the Immunoglobulin Superfamily (Ig-SF). In the present study we describe a cDNA, termed cl.15.212, that encodes for a type I transmembrane protein displaying approximately 50% sequence homology with other Ig-SF members. The protein encoded by cl.15.212 (termed p49 according to its apparent molecular weight of 49 kDa) is characterized by two extracellular Ig-like domains, a 115-amino acid cytoplasmic tail containing a single immuno-receptor tyrosine-based inhibitory motif (ITIM) typical of KIR. Different from the other KIRs, the cl.15.212 transcript is expressed by all NK cells and by a fraction of T-cell clones expressing KIR. To determine the specificity of the cl.15.212-encoded receptor, we generated a chimeric protein, formed by the ectodomain of p49 and the Fc portion of human IgG1 (p49-Fc). Soluble molecules bound efficiently to LCL721.221 (221) cells transfected with HLA-G1, -A3, -B46 alleles and weakly to the -B7 allele. On the other hand, they did not bind to 221 cells either untransfected or transfected with HLA-A2, -B51, -Cw3, or-Cw4.

NK cells display several killer inhibitory receptors (KIR) specific for different alleles of MHC class I molecules. A family of KIR are represented by type I transmembrane proteins belonging to the immunoglobulin superfamily (Ig-SF). Besides cDNA encoding for these KIR, additional cDNA have been identified which encode for Ig-SF receptors with still undefined specificity. Here we analyze one of these cDNA, termed cl.15.212, which encodes a type I transmembrane protein characterized by two extracellular Ig-like domains and a 115-amino acid cytoplasmic tail containing a single immuno-receptor tyrosine-based inhibitory motif (ITIM) which is typical of KIR. cl.15.212 cDNA displays approximately 50 % sequence homology with other Ig-SF members. Different from the other KIR, cl.15.212 mRNA is expressed by all NK cells and by a fraction of KIR+ T cell clones. cl.15.212 cDNA codes for a membrane-bound receptor displaying an apparent molecular mass of 49 kDa, thus termed p49. To determine the specificity of the cl.15.212-encoded receptor, we generated soluble fusion proteins consisting of the ectodomain of p49 and the Fc portion of human IgG1. Soluble molecules bound efficiently to 221 cells transfected with HLA-G1, -A3, -B46 alleles and weakly to -B7 allele. On the other hand, they did not bind to 221 cells either untransfected or transfected with HLA-A2, -B51, -Cw3 or -Cw4. The binding specificity of soluble p49-Fc was confirmed by competition experiments using an anti-HLA class I-specific monoclonal antibody. Finally, different cDNA encoding for molecules homologous to cl.15.212 cDNA have been isolated, two of which lack the sequence encoding the transmembrane portion, thus suggesting they may encode soluble molecules.