1,720,965 research outputs found
First report of chrysodeixis includens nucleopolyhedrovirus (ChinNPV) infecting chrysodeixis includens (Lepidoptera: Noctuidae) in Argentina
Full text linkSummary Typical baculovirus infection symptoms were observed in Chrysodeixis includens Walker (Lepidoptera: Noctuidae) larvae from a laboratory rearing in Tucumán, Argentina. Scanning electron microscopy revealed the occurrence of polyhedral occlusion bodies displaying a heterogeneous morphology. Amplification, sequencing, and phylogenetic analysis of conserved polyhedrin, lef-8 and lef-9 genes identified the pathogen, for the first time in Argentina, as a variant of Chrysodeixis includens nucleopolyhedrovirus (ChinNPV). The biocontrol potential of this new isolate is worthy of future research.Fil: Arneodo Larochette, Joel Demián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Dami, Luciana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Jakubowicz, Violeta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Alzogaray, Raúl Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigaciones de Plagas E Insecticidas; ArgentinaFil: Taibo, Catalina Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentin
Central role of squid gene during oocyte development in the Hemiptera Rhodnius prolixus
No full textOocyte polarity establishment is a conserved and crucial phenomenon for embryonic development. It relies on the precise spatial localization of maternal factors deposited during oocyte development, which is essential for establishing and maintaining cell polarity and subsequently specifying embryonic axes. The heterogeneous nuclear ribonucleoprotein (hnRNP) encoded by the squid (sqd) gene has been implicated in mRNA localization and embryonic axis establishment in Drosophila melanogaster. Comparative genomics allowed for the identification of a homologue in Rhodnius prolixus. In this study, we investigated the function of Rp-sqd during oogenesis and early embryonic development. We observed persistent expression of Rp-sqd during oocyte development, with localization in the cytoplasm of ovary germarium and growing oocytes in previtellogenic and vitellogenic stages. A Parental RNA interference (RNAi) experiment targeting Rp-sqd resulted in female sterility. The ovaries showed disrupted oocyte development, disarray of follicular epithelium, and affected nurse cells integrity. Immunostaining and microscopic techniques revealed microtubule disarray and a reduction in the presence of organelles in the trophic cords that connect the germarium with the oocytes. The Rp-sqd depletion impacted the transcript expression of maternal mRNAs involved in apoptosis, axis formation, oogenesis, and cytoskeleton maintenance, indicating a pleiotropic function of Rp-sqd during oogenesis. This study provides new insights into the genetic basis of R. prolixus oogenesis, highlighting the crucial role of Rp-sqd in oocyte development, fertility, and germarium integrity. These findings contribute to our understanding of insect developmental processes, provide a foundation for future investigations into reproduction, and reveal the regulatory mechanisms governing the process.Fil: Pascual, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Taibo, Catalina Beatriz. No especifíca;Fil: Rivera Pomar, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentin
Light microscopy of microsporidian spores and baculovirus occlusion bodies in Epinotia aporema and Helicoverpa gelotopoeon larval tissues, respectively
No full textEntomopathogens help regulate natural insect populations, and their use in pest management is the subject of active research. Classical and molecular techniques are currently available to elucidate disease etiology and pathogenesis. Here, we performed an Azan trichrome stain for light microscopic visualization of pathogens in the larval tissues of two Neotropical lepidopterans.
Epinotia aporema larvae exhibiting symptoms of microsporidiosis were fortuitously detected in a rearing facility (IMyZA-INTA, Argentina), while Helicoverpa gelotopoeon specimens were experimentally infected with an Argentinean isolate of Helicoverpa armigera nucleopolyhedrovirus (HearNPV). Caterpillars were fixed in Duboscq-Brasil and paraffin embedded. Microtome sections (5 μm-thick) were deparaffinized and stained2 for observation under a Nikon Eclipse 80i microscope equipped with a Nikon DS-U3 digital camera.Inst. de Microbiología y Zoología Agrícola IMyZAFil: Arneodo Larochette, Joel Demian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Taibo, Catalina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Servicio de Microscopía; ArgentinaFil: Sciocco, Alicia Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentin
Biological and molecular characterization of Rachiplusia nu single nucleopolyhedrovirus, a promising biocontrol agent against the South American soybean pest Rachiplusia nu
No full textRachiplusia nu (Lepidoptera: Noctuidae) is a key soybean pest in Argentina. Current management of this moth
relies mainly on the use of synthetic insecticides and transgenic plants. In search of biological control-based
alternatives, a baculovirus from R. nu (hereafter RanuNPV) was characterized and its insecticidal properties
tested under laboratory conditions. RanuNPV occlusion bodies (OBs) were nearly tetrahedral, averaging
1.0 ± 0.2 μm in their longest edge and containing singly enveloped nucleocapsids. Histopathology of infected
late-instar larvae revealed broad tissue tropism, where fat bodies and epidermis were the most affected organs.
Phylogenetic analysis of concatenated polh, lef-8 and lef-9 partial sequences classified RanuNPV as a new species
that clusters with other group II alphabaculoviruses infecting larvae of Plusiinae. Bioassays performed with R. nu
neonates determined the median lethal dosage to be approximately 2.5 OBs/larva; most insects died within
4–5 days post inoculation showing typical baculovirus-induced liquefaction. No effects were observed in other
lepidopteran species assayed, including Spodoptera frugiperda, Cydia pomonella and Diatraea saccharalis. High
pathogenicity and host specificity make RanuNPV a good candidate for controlling R. nu.Instituto de Microbiología y Zoología Agrícola (IMYZA)Fil: Jakubowicz, Violeta. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de investigaciones Científicas y Tecnológicas. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Taibo, Catalina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Servicio de Microscopía; ArgentinaFil: Sciocco, Alicia Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Arneodo Larochette, Joel Demian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de investigaciones Científicas y Tecnológicas. Instituto de Agrobiotecnología y Biología Molecular; Argentin
Comparative Pathogenesis of Generalist AcMNPV and Specific RanuNPV in Larvae of Rachiplusia nu (Lepidoptera: Noctuidae) Following Single and Mixed Inoculations
Full text linkThe South American soybean pest, Rachiplusia nu (Guenée), is naturally infected by Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and Rachiplusia nu nucleopolyhedrovirus (RanuNPV). We compared their pathogenicity to fourth-instar R. nu larvae, by evaluating time to death and virus spread throughout the tissues in single and mixed infections. Bioassays showed that generalist AcMNPV had a faster speed of kill than specific RanuNPV, while the mixed-virus treatment did not statistically differ from AcMNPV alone. Histopathology evidenced similar tissue tropism for both viruses, but co-inoculation resulted in mostly
AcMNPV-infected cells. In sequential inoculations, however, the first virus administered predominated over the second one. Implications on baculovirus interactions and biocontrol potential are discussed.Instituto de Microbiología y Zoología Agrícola (IMYZA)Fil: Decker Franco, Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Decker Franco, Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Taibo, Catalina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Laboratorio Integral de Microscopía; ArgentinaFil: Di Rienzo, Julio A. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Estadística y Biometría; ArgentinaFil: Alfonso, Victoria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Alfonso, Victoria. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Arneodo, Joel D. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Arneodo, Joel D. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentin
Mycoparasitic interaction between Trichoderma afroharzianum strain Th2RI99 and Rhizoctonia solani
No full textThe behavior of Trichoderma afroharzianum strain Th2RI99 confronted to Rhizoctonia solani AG4-HG II in dual culture was observed under light (LM) and scanning electron microscope (SEM). There is evidence of mycoparasitism in the Trichoderma harzianum complex, but no report is available regarding T. afroharzianum, since it has been just recently described as a new species, previously identified with phylogenetic analysis with 3 genes.Instituto de BiotecnologíaFil: Melignani, Eliana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Martin, Mara Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular (IABIMO); ArgentinaFil: Martin, Mara Edith. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mema, Vanesa Yamila. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola (IMYZA); ArgentinaFil: Taibo, Catalina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola (IMYZA); ArgentinaFil: Sabio Y Garcia, Julia Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola (IMYZA); ArgentinaFil: Barrera, Viviana Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola (IMYZA); Argentin
The role of glucose in the pathology of EHEC O157: H7
Full text linkThe pathogen enterohemorrhagic Escherichia coli (EHEC) O157: H7 is responsible for hemorrhagic
colitis and hemolytic uremic syndrome in humans [1]. During the colonization process in the
gastrointestinal tract, EHEC needs to adapt to changes in nutrient availability [2]. The objective of this
study was to evaluate the influence of glucose on physiology and processes involved in the pathogenesis
of EHEC O157: H7 in order to improve our understanding of the mechanisms controlling EHEC growth
and survival in the bovine gut.
In this study we first analyzed the growth rate of EHEC O157: H7 Rafaela II clade 8, a strain isolated
from a bovine in Argentina, grown in the medium DMEM supplemented with either 4.5% glucose (Highglucose - DHG) or 1% glucose (Low-glucose - DLG). In addition, we assessed the bacterial adhesion
capacity and actin pedestal formation induced by EHEC [3] by performing infection assays. For this
purpose, Caco-2 epithelial cells were exposed for 5 h with Rafaela II grown with the different
concentrations of glucose. Subsequently, the samples were fixed (paraformaldehyde 4%) and
permeabilized (triton); actin and nucleic acids (DNA) were stained with rhodamine-phalloidin and TOPRO-3, respectively. Bacterial adhesion capacity and pedestal formation of cells were evaluated using a
Leica TCS SP5 laser scanning confocal microscope (MC). Each Image was acquired by monitoring a
single focal plane over time (xyt scanning mode) using a 40X/1.25 oil objective lens and 543nm HeNe
and 633 nm HeNe lasers. The frequency and resolution for acquiring images were set at 200 Hz and 1,024
x 1,024 pixels, while maintaining the same settings for laser powers, gain, and offset.Instituto de BiotecnologíaFil: Marques Da Silva, Wanderson. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Marques Da Silva, Wanderson. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Taibo, Catalina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Laboratorio Integral de Microscopía; ArgentinaFil: Sabio Y Garcia, Julia Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Sabio Y Garcia, Julia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sabio Y Garcia, Julia Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Laboratorio Integral de Microscopía; ArgentinaFil: Larzabal, Mariano. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Larzabal, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Cataldi, Angel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
